Write release notes for v0.19.0

README.md

@@ -26,6 +26,8 @@ source-relative prompt content, supplies an inline input, and prepares through
 a scoped view. The example also demonstrates collection inventories and
 namespace-filtered discovery, without contacting a provider or requiring
 credentials.
+The example disables the bundled OpenRouter configuration to keep its
+inventories limited to its own offline fixtures.
 The [consumer guide](docs/consumers/pkg-promptkit.md) also shows a local backend,
 ordered file/embedded sources, programmatic mappings, and how to replace an
 engine when source files change. Applications adapting the prior keyed
@@ -43,6 +45,11 @@ boundary and constraints that framework work must preserve.
 
 ## Release Guidance
 
+The [v0.18.0 release notes](docs/releases/v0.18.0.md) cover the default-on
+OpenRouter backend and profiles, recorded configuration normalization, and
+ConfigKit v1.1. The notes explain inventory changes and the bundle opt-out;
+the Go 1.27 minimum remains unchanged.
+
 The [v0.17.0 release notes](docs/releases/v0.17.0.md) cover the vanity module
 path, ConfigKit v1, identified resource lists, removal of prompt-version
 metadata, and the Go 1.27 minimum. This is a breaking pre-v1 migration.

artifact_ownership_contract_test.go

@@ -0,0 +1,43 @@
+package promptkit_test
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"testing"
+
+	"go.maximumdirect.net/configkit"
+	"go.maximumdirect.net/promptkit"
+)
+
+type independentArtifactReader struct{}
+
+func (independentArtifactReader) Read(_ context.Context, ref promptkit.ArtifactRef) (*promptkit.Artifact, error) {
+	return &promptkit.Artifact{Body: []byte(ref.Body), Hash: ref.Body}, nil
+}
+
+func TestConcurrentPreparationWithTransferredArtifacts(t *testing.T) {
+	input := configkit.Input{Source: configkit.Mapping("ownership", map[string]any{
+		"profiles": []any{map[string]any{"id": "profile", "endpoint": "https://example.invalid/v1", "model": "model"}},
+		"prompts":  []any{map[string]any{"id": "prompt", "default_profile": "profile", "inputs": []any{map[string]any{"name": "document", "required": true}}, "messages": []any{map[string]any{"role": "user", "content": `{{input "document"}}`}}, "output": map[string]any{"format": "text", "validation_mode": "none"}}},
+	})}
+	engine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Main: &input}}, promptkit.WithArtifactReader(independentArtifactReader{}))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var group sync.WaitGroup
+	for i := range 24 {
+		group.Go(func() {
+			value := fmt.Sprintf("body-%d", i)
+			prepared, err := engine.Prepare(context.Background(), promptkit.RunRequest{PromptID: "prompt", Inputs: map[string]promptkit.ArtifactRef{"document": promptkit.Inline(value)}})
+			if err != nil {
+				t.Errorf("prepare: %v", err)
+				return
+			}
+			if len(prepared.Messages) != 1 || prepared.Messages[0].Content != value || prepared.InputHashes["document"] != value {
+				t.Errorf("prepared = %+v", prepared)
+			}
+		})
+	}
+	group.Wait()
+}

backends.go

@@ -78,7 +78,8 @@ type AuthenticationProbeConfig struct {
 // It encodes fields without validating them; NewEngine validates the final
 // effective configuration after all selected source layers are combined.
 // Mapping captures a copy of supported input values at creation; unsupported
-// values fail when the source is loaded.
+// values fail when the source is loaded. ExtraParams must use ConfigKit Mapping
+// input forms; callers must explicitly convert numbers or containers as needed.
 func BackendSource(label string, backends []BackendConfig) configkit.Source {
 	definitions := make([]any, 0, len(backends))
 	for _, config := range backends {
@@ -96,7 +97,7 @@ func BackendSource(label string, backends []BackendConfig) configkit.Source {
 			fields["queue_capacity"] = *config.QueueCapacity
 		}
 		if config.ExtraParams != nil {
-			fields["extra_params"] = providerMapForMapping(config.ExtraParams)
+			fields["extra_params"] = config.ExtraParams
 		}
 		if config.SmokeTests != nil {
 			smokeTests := make(map[string]any)

bundled_composition_contract_test.go

@@ -0,0 +1,114 @@
+package promptkit_test
+
+import (
+	"context"
+	"reflect"
+	"slices"
+	"testing"
+
+	"go.maximumdirect.net/configkit"
+	"go.maximumdirect.net/promptkit"
+)
+
+func TestBundledCompositionReplacementAndInheritance(t *testing.T) {
+	underlay := configkit.Input{Source: configkit.Mapping("caller underlay", map[string]any{
+		"profiles": []any{map[string]any{"id": "gpt-sol-latest", "model": "underlay-model"}},
+	})}
+	underlayEngine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{underlay}}}}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	underlayProfile, err := underlayEngine.InspectProfile(context.Background(), "gpt-sol-latest")
+	if err != nil || underlayProfile.EffectiveModelParams.Model != "underlay-model" || underlayProfile.EffectiveModelParams.BackendID != "" {
+		t.Fatalf("underlay replacement = %+v, %v", underlayProfile, err)
+	}
+	main := configkit.Input{Source: configkit.Mapping("caller main", map[string]any{
+		"backends": []any{map[string]any{"id": "openrouter", "endpoint": "https://local.invalid/v1"}, map[string]any{"id": "other", "endpoint": "https://other.invalid/v1"}},
+		"profiles": []any{
+			map[string]any{"id": "gpt-sol-latest", "model": "main-model"},
+			map[string]any{"id": "custom", "extends": map[string]any{"id": "gpt-luna-latest"}, "model": "custom-model"},
+			map[string]any{"id": "auto", "backend": "other", "model": "other-model"},
+		},
+		"collections": map[string]any{"openrouter": map[string]any{
+			"backends": []any{map[string]any{"id": "local", "endpoint": "https://collection.invalid/v1"}},
+			"profiles": []any{map[string]any{"id": "profile", "backend": "openrouter/local", "model": "collection-model"}},
+		}},
+	})}
+	engine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{underlay}}}, Main: &main}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	inspect := func(id string) promptkit.ExecutionTarget {
+		t.Helper()
+		profile, err := engine.InspectProfile(context.Background(), id)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return profile.EffectiveModelParams
+	}
+	if target := inspect("gpt-sol-latest"); target.Model != "main-model" || target.BackendID != "" {
+		t.Fatalf("replacement = %+v", target)
+	}
+	if target := inspect("custom"); target.Model != "custom-model" || target.BackendID != "openrouter" || target.Endpoint != "https://local.invalid/v1" {
+		t.Fatalf("inherited = %+v", target)
+	}
+	if target := inspect("gpt-luna-latest"); target.Endpoint != "https://local.invalid/v1" || target.APIKeyEnv != "" {
+		t.Fatalf("backend replacement = %+v", target)
+	}
+	if target := inspect("openrouter/profile"); target.BackendID != "openrouter/local" || target.Model != "collection-model" {
+		t.Fatalf("collection = %+v", target)
+	}
+	target := inspect("auto-low")
+	wantPlugins := map[string]any{"plugins": []any{map[string]any{"id": "auto-router", "cost_tier": "low"}}}
+	if target.BackendID != "other" || target.Model != "other-model" || !reflect.DeepEqual(target.ExtraParams, wantPlugins) {
+		t.Errorf("inherited tier = %+v", target)
+	}
+}
+
+func TestBundledCompositionSequenceModes(t *testing.T) {
+	for _, test := range []struct {
+		name, mode, id string
+		wantErr        bool
+		hasAuto        bool
+	}{
+		{"duplicate append", "append", "auto", true, false},
+		{"distinct append", "append", "custom", false, true},
+		{"replace", "replace", "custom", false, false},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			input := configkit.Input{Source: configkit.Mapping("sequence", map[string]any{
+				"config":   map[string]any{"sequences": []any{map[string]any{"destination": []any{"profiles"}, "mode": test.mode}}},
+				"profiles": []any{map[string]any{"id": test.id, "model": "custom-model"}},
+			})}
+			engine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Main: &input}})
+			if test.wantErr {
+				if err == nil {
+					t.Fatal("expected duplicate rejection")
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			profiles, err := engine.ListProfiles(context.Background())
+			if err != nil || !slices.Contains(profiles, "custom") || slices.Contains(profiles, "auto") != test.hasAuto {
+				t.Fatalf("profiles = %v, %v", profiles, err)
+			}
+		})
+	}
+}
+
+func TestBundledCompositionRejectsStrictConflictsAndMissingBackends(t *testing.T) {
+	profile := configkit.Input{Source: configkit.Mapping("profile", map[string]any{"profiles": []any{map[string]any{"id": "auto", "model": "caller"}}})}
+	_, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{profile, profile}}}}})
+	if err == nil {
+		t.Fatal("strict group accepted duplicate records")
+	}
+	input := configkit.Input{Source: configkit.Mapping("replace backends", map[string]any{
+		"config":   map[string]any{"sequences": []any{map[string]any{"destination": []any{"backends"}, "mode": "replace"}}},
+		"backends": []any{map[string]any{"id": "other", "endpoint": "https://other.invalid/v1"}},
+	})}
+	if _, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Main: &input}}); err == nil {
+		t.Fatal("missing bundled backend was accepted")
+	}
+}

bundled_execution_contract_test.go

@@ -0,0 +1,89 @@
+package promptkit_test
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"reflect"
+	"strings"
+	"testing"
+
+	"go.maximumdirect.net/configkit"
+	"go.maximumdirect.net/promptkit"
+)
+
+func bundledPromptConfig(client *http.Client) promptkit.Config {
+	input := configkit.Input{Source: configkit.Mapping("prompt", map[string]any{"prompts": []any{map[string]any{
+		"id": "prompt", "messages": []any{map[string]any{"role": "user", "content": "hello"}}, "output": map[string]any{"format": "text", "validation_mode": "none"},
+	}}})}
+	return promptkit.Config{HTTPClient: client, Sources: promptkit.ConfigurationSources{Main: &input}}
+}
+
+func TestBundledProfilePreparationAndExecution(t *testing.T) {
+	client := &fakeLLMClient{response: &promptkit.GenerateResponse{Content: "ok"}}
+	engine, err := promptkit.NewEngine(bundledPromptConfig(nil), promptkit.WithLLMClient(client))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := engine.PrepareExecution(context.Background(), promptkit.RunRequest{PromptID: "prompt"}); !errors.Is(err, promptkit.ErrProfileRequired) {
+		t.Fatalf("missing profile = %v", err)
+	}
+	temperature := 0.3
+	request := promptkit.RunRequest{PromptID: "prompt", ProfileID: "gpt-luna-latest", Execution: &promptkit.ExecutionTargetOverride{Temperature: &temperature}}
+	prepared, err := engine.PrepareExecution(context.Background(), request)
+	if err != nil {
+		t.Fatal(err)
+	}
+	details := prepared.Details()
+	if details.SelectedProfileID != "gpt-luna-latest" || details.EffectiveModelParams.Model != "~openai/gpt-luna-latest" || details.EffectiveModelParams.BackendID != "openrouter" || details.EffectiveModelParams.Temperature != temperature {
+		t.Fatalf("prepared target = %+v", details.EffectiveModelParams)
+	}
+	if _, err := engine.Run(context.Background(), request); err != nil {
+		t.Fatal(err)
+	}
+	if len(client.requests) != 1 || client.requests[0].Target.Model != "~openai/gpt-luna-latest" || client.requests[0].Target.BackendID != "openrouter" {
+		t.Fatalf("requests = %+v", client.requests)
+	}
+}
+
+func TestBundledProfileHTTPPayloads(t *testing.T) {
+	t.Setenv("OPENROUTER_API_KEY", "synthetic-key")
+	for _, test := range []struct{ id, model, tier string }{
+		{"auto-low", "openrouter/auto", "low"}, {"gpt-luna-latest", "~openai/gpt-luna-latest", ""},
+	} {
+		t.Run(test.id, func(t *testing.T) {
+			var body map[string]any
+			transport := roundTripFunc(func(request *http.Request) (*http.Response, error) {
+				if request.Header.Get("Authorization") != "Bearer synthetic-key" {
+					t.Errorf("authorization = %q", request.Header.Get("Authorization"))
+				}
+				if err := json.NewDecoder(request.Body).Decode(&body); err != nil {
+					t.Fatal(err)
+				}
+				return &http.Response{StatusCode: 200, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(`{"choices":[{"message":{"content":"ok"}}]}`))}, nil
+			})
+			engine, err := promptkit.NewEngine(bundledPromptConfig(&http.Client{Transport: transport}))
+			if err != nil {
+				t.Fatal(err)
+			}
+			if _, err := engine.Run(context.Background(), promptkit.RunRequest{PromptID: "prompt", ProfileID: test.id}); err != nil {
+				t.Fatal(err)
+			}
+			if body["model"] != test.model || body["extra_params"] != nil {
+				t.Fatalf("request = %+v", body)
+			}
+			if test.tier == "" {
+				if _, exists := body["plugins"]; exists {
+					t.Fatalf("unexpected plugins = %+v", body)
+				}
+				return
+			}
+			want := []any{map[string]any{"id": "auto-router", "cost_tier": test.tier}}
+			if !reflect.DeepEqual(body["plugins"], want) {
+				t.Fatalf("plugins = %#v, want %#v", body["plugins"], want)
+			}
+		})
+	}
+}

bundled_openrouter_contract_test.go

@@ -0,0 +1,117 @@
+package promptkit_test
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"reflect"
+	"strings"
+	"testing"
+
+	"go.maximumdirect.net/configkit"
+	"go.maximumdirect.net/promptkit"
+)
+
+type rejectBundleTransport struct{}
+
+func (rejectBundleTransport) RoundTrip(*http.Request) (*http.Response, error) {
+	return nil, errors.New("unexpected HTTP request")
+}
+
+func TestBundledOpenRouterOptionsAndInventory(t *testing.T) {
+	t.Setenv("OPENROUTER_API_KEY", "")
+	for _, test := range []struct {
+		name    string
+		options []promptkit.Option
+		enabled bool
+	}{
+		{"default", nil, true}, {"enabled", []promptkit.Option{promptkit.WithBundledOpenRouter(true)}, true},
+		{"disabled", []promptkit.Option{promptkit.WithBundledOpenRouter(false)}, false},
+		{"last disables", []promptkit.Option{promptkit.WithBundledOpenRouter(true), promptkit.WithBundledOpenRouter(false)}, false},
+		{"last enables", []promptkit.Option{promptkit.WithBundledOpenRouter(false), promptkit.WithBundledOpenRouter(true)}, true},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			engine, err := promptkit.NewEngine(promptkit.Config{HTTPClient: &http.Client{Transport: rejectBundleTransport{}}}, test.options...)
+			if err != nil {
+				t.Fatal(err)
+			}
+			profiles, err := engine.ListProfiles(context.Background())
+			if err != nil {
+				t.Fatal(err)
+			}
+			backends, err := engine.ListBackends(context.Background())
+			if err != nil {
+				t.Fatal(err)
+			}
+			prompts, err := engine.ListPrompts(context.Background())
+			if err != nil {
+				t.Fatal(err)
+			}
+			collections, err := engine.ListCollections(context.Background())
+			if err != nil {
+				t.Fatal(err)
+			}
+			if (len(profiles) > 0) != test.enabled || len(backends) != boolCount(test.enabled) || len(prompts) != 0 || len(collections) != 0 {
+				t.Fatalf("inventories: %v %v %v %v", profiles, backends, prompts, collections)
+			}
+			if test.enabled {
+				if !reflect.DeepEqual(backends, []string{"openrouter"}) {
+					t.Fatalf("bundle inventory: %v %v", profiles, backends)
+				}
+				profile, err := engine.InspectProfile(context.Background(), "auto")
+				if err != nil || profile.EffectiveModelParams.BackendID != "openrouter" {
+					t.Fatalf("bundle profile = %+v, %v", profile, err)
+				}
+				view, err := engine.InspectConfiguration()
+				if err != nil {
+					t.Fatal(err)
+				}
+				if !strings.Contains(fmtSources(view.Sources()), "Promptkit bundled OpenRouter") {
+					t.Fatal("bundle source missing")
+				}
+				if explanation, found := view.Explain(configkit.Keys("backends").Index(0).Key("endpoint")); !found || !strings.Contains(explanation.Effective.YAML, "https://openrouter.ai/api/v1") || len(explanation.History) == 0 {
+					t.Fatalf("bundle explanation = %+v", explanation)
+				}
+			}
+		})
+	}
+}
+
+func boolCount(value bool) int {
+	if value {
+		return 1
+	}
+	return 0
+}
+func fmtSources(sources []configkit.SourceInfo) string {
+	var b strings.Builder
+	for _, source := range sources {
+		b.WriteString(source.Label)
+	}
+	return b.String()
+}
+
+func TestBundlePreservesCallerUnderlayBackingArray(t *testing.T) {
+	source := configkit.Mapping("caller", map[string]any{"profiles": []any{map[string]any{"id": "caller", "model": "model"}}})
+	groups := make([]configkit.Underlay, 1, 2)
+	groups[0] = configkit.Underlay{Inputs: []configkit.Input{{Source: source}}}
+	before := append([]configkit.Underlay(nil), groups...)
+	if _, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Underlays: groups}}); err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(groups, before) || !reflect.DeepEqual(groups[:2][1], configkit.Underlay{}) {
+		t.Fatal("caller underlays were modified")
+	}
+}
+
+func TestDisabledBundleKeepsCallerOpenRouter(t *testing.T) {
+	input := configkit.Input{Source: configkit.Mapping("caller", map[string]any{"backends": []any{map[string]any{"id": "openrouter", "endpoint": "https://local.invalid/v1"}}})}
+	engine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Main: &input}}, promptkit.WithBundledOpenRouter(false))
+	if err != nil {
+		t.Fatal(err)
+	}
+	backends, err := engine.ListBackends(context.Background())
+	if err != nil || !reflect.DeepEqual(backends, []string{"openrouter"}) {
+		t.Fatalf("backends = %v, %v", backends, err)
+	}
+}

bundled_smoke_contract_test.go

@@ -0,0 +1,181 @@
+package promptkit_test
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"reflect"
+	"strings"
+	"testing"
+
+	"go.maximumdirect.net/configkit"
+	"go.maximumdirect.net/promptkit"
+)
+
+type cancelingAuthenticationBody struct {
+	remaining int
+	cancel    context.CancelFunc
+	closed    bool
+}
+
+func (b *cancelingAuthenticationBody) Read(p []byte) (int, error) {
+	n := min(len(p), b.remaining)
+	for i := range p[:n] {
+		p[i] = 'x'
+	}
+	b.remaining -= n
+	if b.remaining == 0 {
+		b.cancel()
+		return n, context.Canceled
+	}
+	return n, nil
+}
+func (b *cancelingAuthenticationBody) Close() error { b.closed = true; return nil }
+
+func TestAuthenticationReadCancellationWinsOverOverflow(t *testing.T) {
+	for _, size := range []int{1024, (1 << 20) + 1} {
+		ctx, cancel := context.WithCancel(context.Background())
+		body := &cancelingAuthenticationBody{remaining: size, cancel: cancel}
+		engine, err := promptkit.NewEngine(promptkit.Config{HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
+			return &http.Response{StatusCode: 200, Header: make(http.Header), Body: body}, nil
+		})}})
+		if err != nil {
+			cancel()
+			t.Fatal(err)
+		}
+		report, err := engine.SmokeTest(ctx, promptkit.SmokeTestRequest{Kind: promptkit.SmokeTestAuthentication, BackendID: "openrouter"})
+		cancel()
+		if !errors.Is(err, context.Canceled) || report == nil || report.Completed || report.Failure != promptkit.ExecutionFailureCanceled || report.Facts.CredentialsAccepted != nil || report.Facts.ResponseReceived == nil || !*report.Facts.ResponseReceived || !body.closed {
+			t.Fatalf("size %d: report=%+v error=%v closed=%v", size, report, err, body.closed)
+		}
+	}
+}
+
+func TestBundledSmokeHTTPDefaults(t *testing.T) {
+	t.Setenv("OPENROUTER_API_KEY", "synthetic-key")
+	var urls []string
+	var models []string
+	transport := roundTripFunc(func(request *http.Request) (*http.Response, error) {
+		urls = append(urls, request.URL.String())
+		body := `{"data":{"label":"member","is_free_tier":false,"usage":0}}`
+		if request.Method == http.MethodPost {
+			var payload map[string]any
+			if err := json.NewDecoder(request.Body).Decode(&payload); err != nil {
+				t.Fatal(err)
+			}
+			models = append(models, payload["model"].(string))
+			content := "PROMPTKIT_OK"
+			if _, structured := payload["response_format"]; structured {
+				content = `{"status":"ok"}`
+			}
+			encoded, err := json.Marshal(map[string]any{"choices": []any{map[string]any{"message": map[string]any{"content": content}}}})
+			if err != nil {
+				t.Fatal(err)
+			}
+			body = string(encoded)
+		} else if strings.HasSuffix(request.URL.Path, "/key") && request.Header.Get("Authorization") != "Bearer synthetic-key" {
+			t.Errorf("authentication header missing")
+		}
+		return &http.Response{StatusCode: 200, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(body))}, nil
+	})
+	engine, err := promptkit.NewEngine(promptkit.Config{HTTPClient: &http.Client{Transport: transport}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	before, _ := engine.ListProfiles(context.Background())
+	inspectionBefore, err := engine.InspectConfiguration()
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, kind := range []promptkit.SmokeTestKind{promptkit.SmokeTestReachability, promptkit.SmokeTestAuthentication, promptkit.SmokeTestTextInference, promptkit.SmokeTestStructuredOutput} {
+		report, err := engine.SmokeTest(context.Background(), promptkit.SmokeTestRequest{Kind: kind, BackendID: "openrouter"})
+		if err != nil || report == nil || !report.Completed || report.Failure != "" {
+			t.Fatalf("%s report = %+v, %v", kind, report, err)
+		}
+		if kind == promptkit.SmokeTestAuthentication && (report.Facts.CredentialsAccepted == nil || !*report.Facts.CredentialsAccepted) {
+			t.Fatalf("authentication facts = %+v", report.Facts)
+		}
+		if kind == promptkit.SmokeTestTextInference || kind == promptkit.SmokeTestStructuredOutput {
+			if report.Target.ProfileID != "gpt-luna-latest" || report.Target.EffectiveSettings.Model != "~openai/gpt-luna-latest" {
+				t.Fatalf("target = %+v", report.Target)
+			}
+		}
+	}
+	wantURLs := []string{"https://openrouter.ai/api/v1", "https://openrouter.ai/api/v1/key", "https://openrouter.ai/api/v1/chat/completions", "https://openrouter.ai/api/v1/chat/completions"}
+	if !reflect.DeepEqual(urls, wantURLs) || !reflect.DeepEqual(models, []string{"~openai/gpt-luna-latest", "~openai/gpt-luna-latest"}) {
+		t.Fatalf("urls %v, models %v", urls, models)
+	}
+	after, _ := engine.ListProfiles(context.Background())
+	if !reflect.DeepEqual(before, after) {
+		t.Fatalf("inventory changed: %v %v", before, after)
+	}
+	inspectionAfter, err := engine.InspectConfiguration()
+	if err != nil {
+		t.Fatal(err)
+	}
+	diff, err := inspectionBefore.Diff(inspectionAfter)
+	if err != nil || len(diff) != 0 {
+		t.Fatalf("inspection changed: %+v, %v", diff, err)
+	}
+}
+
+func TestBundledSmokeSelectionUsesEffectiveConfiguration(t *testing.T) {
+	replacement := configkit.Input{Source: configkit.Mapping("replacement", map[string]any{"profiles": []any{map[string]any{"id": "gpt-luna-latest", "backend": "openrouter", "model": "replacement"}}})}
+	replacementClient := &fakeLLMClient{response: &promptkit.GenerateResponse{Content: "PROMPTKIT_OK"}}
+	replacementEngine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Main: &replacement}}, promptkit.WithLLMClient(replacementClient))
+	if err != nil {
+		t.Fatal(err)
+	}
+	replacementReport, err := replacementEngine.SmokeTest(context.Background(), promptkit.SmokeTestRequest{Kind: promptkit.SmokeTestTextInference, BackendID: "openrouter"})
+	if err != nil || replacementReport.Target.ProfileID != "gpt-luna-latest" || replacementReport.Target.EffectiveSettings.Model != "replacement" {
+		t.Fatalf("replaced default = %+v, %v", replacementReport, err)
+	}
+	replacementClient.response.Content = "unexpected"
+	mismatch, err := replacementEngine.SmokeTest(context.Background(), promptkit.SmokeTestRequest{Kind: promptkit.SmokeTestTextInference, BackendID: "openrouter"})
+	if err != nil || mismatch == nil || !mismatch.Completed {
+		t.Fatalf("concluded mismatch = %+v, %v", mismatch, err)
+	}
+	input := configkit.Input{Source: configkit.Mapping("application", map[string]any{
+		"backends": []any{map[string]any{"id": "openrouter", "endpoint": "https://example.invalid/v1", "smoke_tests": map[string]any{"default_profile": "custom"}}},
+		"profiles": []any{map[string]any{"id": "gpt-luna-latest", "backend": "openrouter", "model": "replacement"}, map[string]any{"id": "custom", "backend": "openrouter", "model": "custom-model"}},
+		"prompts":  []any{map[string]any{"id": "prompt", "default_profile": "free", "messages": []any{map[string]any{"role": "user", "content": "private application marker"}}, "output": map[string]any{"format": "text", "validation_mode": "none"}}},
+	})}
+	client := &fakeLLMClient{response: &promptkit.GenerateResponse{Content: "PROMPTKIT_OK"}}
+	engine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Main: &input}}, promptkit.WithLLMClient(client))
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, test := range []struct {
+		request        promptkit.SmokeTestRequest
+		profile, model string
+	}{
+		{promptkit.SmokeTestRequest{BackendID: "openrouter"}, "custom", "custom-model"},
+		{promptkit.SmokeTestRequest{BackendID: "openrouter", PromptID: "prompt"}, "free", "openrouter/free"},
+		{promptkit.SmokeTestRequest{BackendID: "openrouter", PromptID: "prompt", ProfileID: "gpt-luna-latest"}, "gpt-luna-latest", "replacement"},
+	} {
+		test.request.Kind = promptkit.SmokeTestTextInference
+		report, err := engine.SmokeTest(context.Background(), test.request)
+		if err != nil || report.Target.ProfileID != test.profile || report.Target.EffectiveSettings.Model != test.model {
+			t.Fatalf("report = %+v, %v", report, err)
+		}
+		if strings.Contains(client.requests[len(client.requests)-1].Prompt.Messages[0].Content, "private application marker") {
+			t.Fatal("application content used by diagnostic")
+		}
+	}
+}
+
+func TestBundledSmokeAuthenticationResponseOverflow(t *testing.T) {
+	transport := roundTripFunc(func(*http.Request) (*http.Response, error) {
+		return &http.Response{StatusCode: 200, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(strings.Repeat("x", (1<<20)+1)))}, nil
+	})
+	engine, err := promptkit.NewEngine(promptkit.Config{HTTPClient: &http.Client{Transport: transport}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	report, err := engine.SmokeTest(context.Background(), promptkit.SmokeTestRequest{Kind: promptkit.SmokeTestAuthentication, BackendID: "openrouter", APIKey: "private-key-marker"})
+	if err != nil || report == nil || !report.Completed || report.Reason != promptkit.SmokeTestReasonAuthenticationResponseLimitExceeded || report.Failure != promptkit.ExecutionFailureOther || report.Facts.CredentialsAccepted != nil {
+		t.Fatalf("overflow = %+v, %v", report, err)
+	}
+}

configuration_diff_contract_test.go

@@ -81,6 +81,34 @@ func TestConfigurationInspectionDiffIgnoresSourceHistory(t *testing.T) {
 	}
 }
 
+func TestConfigurationInspectionDiffUsesNormalizedValues(t *testing.T) {
+	inspect := func(endpoint string) promptkit.ConfigurationInspection {
+		t.Helper()
+		engine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{{Source: configkit.Mapping("backend", map[string]any{
+			"backends": []any{map[string]any{"id": "local", "endpoint": endpoint}},
+		})}}}}}})
+		if err != nil {
+			t.Fatal(err)
+		}
+		view, err := engine.InspectConfiguration()
+		if err != nil {
+			t.Fatal(err)
+		}
+		return view
+	}
+	left := inspect(" HTTPS://example.invalid/v1 ")
+	equal := inspect("https://example.invalid/v1")
+	differences, err := left.Diff(equal)
+	if err != nil || len(differences) != 0 {
+		t.Fatalf("normalized diff = %+v, %v", differences, err)
+	}
+	changed := inspect("https://other.invalid/v1")
+	differences, err = left.Diff(changed)
+	if err != nil || len(differences) != 1 || differences[0].Path.String() != "/backends" {
+		t.Fatalf("changed diff = %+v, %v", differences, err)
+	}
+}
+
 func TestConfigurationInspectionDiffReportsPresenceAndSequences(t *testing.T) {
 	left := comparisonInspectionFrom(t, "before", "same-model", map[string]any{
 		"sequence": []any{"earlier", "unchanged"},

configuration_inspection_contract_test.go

@@ -21,7 +21,7 @@ func TestConfigurationInspectionReportsLiteralKeysAndRedactedHistory(t *testing.
 		Underlays: []configkit.Underlay{
 			{Inputs: []configkit.Input{{Source: configkit.Mapping("defaults", map[string]any{
 				"backends": []any{map[string]any{
-					"id": "local", "endpoint": "https://example.invalid/v1", "api_key_env": "OPTIONAL_KEY",
+					"id": "local", "endpoint": " HTTPS://example.invalid/v1 ", "api_key_env": "OPTIONAL_KEY",
 					"extra_params": map[string]any{"token": "private-sentinel", "visible": "public-value"},
 				}},
 				"collections": map[string]any{"literal": map[string]any{
@@ -42,7 +42,7 @@ func TestConfigurationInspectionReportsLiteralKeysAndRedactedHistory(t *testing.
 				}},
 			})}}},
 		},
-	}})
+	}}, promptkit.WithBundledOpenRouter(false))
 	if err != nil {
 		t.Fatalf("construct layered engine: %v", err)
 	}
@@ -64,6 +64,11 @@ func TestConfigurationInspectionReportsLiteralKeysAndRedactedHistory(t *testing.
 		t.Fatalf("literal-key path = %q", inheritedPath)
 	}
 	secretPath := configkit.Keys("backends").Index(0).Key("extra_params").Key("token")
+	endpointPath := configkit.Keys("backends").Index(0).Key("endpoint")
+	endpoint, found := view.Explain(endpointPath)
+	if !found || !strings.Contains(endpoint.Effective.YAML, "https://example.invalid/v1") || strings.Contains(fmt.Sprintf("%+v", view.Metadata().History(endpointPath)), "private-sentinel") {
+		t.Fatalf("normalized endpoint explanation = %+v", endpoint)
+	}
 	secret, found := view.Explain(secretPath)
 	if !found || !secret.Effective.Redacted || strings.Contains(secret.Effective.YAML, "private-sentinel") {
 		t.Fatalf("credential-shaped provider value was not redacted: (%+v, %t)", secret, found)

construction_contract_test.go

@@ -291,7 +291,7 @@ func TestBackendSourceOwnsSmokeTestValuesAndDefersDefaultLookup(t *testing.T) {
 		"https://backend.example/v1",
 		"not-yet-listed",
 		"https://probe.example/ready?check=1",
-		" OPENROUTER_KEY ",
+		"openrouter_key",
 		"https://probe.example/key?scope=current",
 	} {
 		if !strings.Contains(contents, want) {

convert.go

@@ -2,7 +2,6 @@ package promptkit
 
 import (
 	"fmt"
-	"reflect"
 	"unicode/utf8"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
@@ -395,88 +394,10 @@ func copyAnyMap(src map[string]any) map[string]any {
 	if src == nil {
 		return nil
 	}
-	out := make(map[string]any, len(src))
+	return jsonvalue.CloneTrusted(src).(map[string]any)
-	for k, v := range src {
-		out[k] = copyAny(v)
-	}
-	return out
 }
 
-func copyAny(value any) any {
+func copyAny(value any) any { return jsonvalue.CloneTrusted(value) }
-	if value == nil {
-		return nil
-	}
-	switch v := value.(type) {
-	case map[string]any:
-		return copyAnyMap(v)
-	case []any:
-		out := make([]any, len(v))
-		for i, item := range v {
-			out[i] = copyAny(item)
-		}
-		return out
-	case []string:
-		return copyStringSlice(v)
-	case []byte:
-		return copyBytes(v)
-	default:
-		return copyReflectValue(reflect.ValueOf(value)).Interface()
-	}
-}
-
-func copyReflectValue(value reflect.Value) reflect.Value {
-	if !value.IsValid() {
-		return value
-	}
-
-	switch value.Kind() {
-	case reflect.Interface:
-		if value.IsNil() {
-			return reflect.Zero(value.Type())
-		}
-		copied := copyReflectValue(value.Elem())
-		if copied.IsValid() && copied.Type().AssignableTo(value.Type()) {
-			return copied
-		}
-		out := reflect.New(value.Type()).Elem()
-		out.Set(copied)
-		return out
-	case reflect.Pointer:
-		if value.IsNil() {
-			return reflect.Zero(value.Type())
-		}
-		out := reflect.New(value.Type().Elem())
-		out.Elem().Set(copyReflectValue(value.Elem()))
-		return out
-	case reflect.Map:
-		if value.IsNil() {
-			return reflect.Zero(value.Type())
-		}
-		out := reflect.MakeMapWithSize(value.Type(), value.Len())
-		iter := value.MapRange()
-		for iter.Next() {
-			out.SetMapIndex(copyReflectValue(iter.Key()), copyReflectValue(iter.Value()))
-		}
-		return out
-	case reflect.Slice:
-		if value.IsNil() {
-			return reflect.Zero(value.Type())
-		}
-		out := reflect.MakeSlice(value.Type(), value.Len(), value.Cap())
-		for i := 0; i < value.Len(); i++ {
-			out.Index(i).Set(copyReflectValue(value.Index(i)))
-		}
-		return out
-	case reflect.Array:
-		out := reflect.New(value.Type()).Elem()
-		for i := 0; i < value.Len(); i++ {
-			out.Index(i).Set(copyReflectValue(value.Index(i)))
-		}
-		return out
-	default:
-		return value
-	}
-}
 
 func copyStringSlice(src []string) []string {
 	if src == nil {

docs/consumers/configuration-migration.md

@@ -3,7 +3,7 @@
 This breaking pre-v1 minor migration adopts Promptkit's vanity module path,
 changes the v0.16-era keyed resources to identified lists, adopts ConfigKit v1,
 and removes prompt-version labels.
-Promptkit does not install a provider catalog; applications choose configuration
+Promptkit installs a default-on bundled OpenRouter catalog; applications choose configuration
 inputs explicitly, and execution selects one prompt by its exact ID. This guide
 explains the shape changes and decisions an application must make; it is not an
 automatic migration tool. The [framework format reference](../formats.md) owns
@@ -134,13 +134,15 @@ Replace former maps passed to `BackendSource` in the same way, setting each
 `BackendConfig.ID`. Duplicates are retained for loading to reject. Resource
 inspection paths now address list indexes, for example
 `configkit.Keys("profiles").Index(0).Key("model")`. Configuration inspection
-and diffs expose composed values and provenance, while `InspectProfile` and
+and diffs expose resolved values, recorded normalization and provenance.
-other interpreted views expose Promptkit normalization and defaults; the views
+`InspectProfile` additionally applies backend completion; request preparation
-are not promised to be identical.
+can apply further overrides, so the views are not promised to be identical.
 
 Remove `PromptVersion` and `PromptIdentity.Version` uses and the corresponding
-`prompt_version` JSON members. Prompt hashes are opaque equality values and may
+`prompt_version` JSON members. Prompt definition hashes are opaque equality
-change when the removed field no longer participates in hashing.
+values and may also change because redundant captured fields were removed.
+Invalidate persisted caches or comparisons that span this change; hashes from
+inspection and preparation of the same captured definition still agree.
 
 ## Identity Mapping
 

docs/consumers/pkg-promptkit.md

@@ -18,7 +18,7 @@ import "go.maximumdirect.net/promptkit"
 For migration from the former module path, see
 [Update Go Imports](configuration-migration.md#update-go-imports).
 
-Configuration APIs use `go.maximumdirect.net/configkit` v1.0.0. Its types are
+Configuration APIs use `go.maximumdirect.net/configkit` v1.1.0. Its types are
 not interchangeable with the old ConfigKit module path.
 
 The maintained [offline preparation example](../../examples/go-library/prepare/main.go)
@@ -52,6 +52,32 @@ Create an engine with [`NewEngine`](../../engine.go). Select each directory
 explicitly and place its inputs in an ordered ConfigKit underlay. A group
 strictly composes its files; later groups can overlay earlier ones:
 
+The bundled OpenRouter backend and profiles are installed in a lower underlay
+by default. Select a profile explicitly, for example:
+
+```go
+input := configkit.Input{Source: configkit.Mapping("application", map[string]any{
+	"prompts": []any{map[string]any{
+		"id": "my-prompt",
+		"messages": []any{map[string]any{"role": "user", "content": "Hello"}},
+		"output": map[string]any{"format": "text", "validation_mode": "none"},
+	}},
+})}
+engine, err := promptkit.NewEngine(promptkit.Config{Sources: promptkit.ConfigurationSources{Main: &input}})
+if err != nil { return err }
+result, err := engine.Run(ctx, promptkit.RunRequest{PromptID: "my-prompt", ProfileID: "gpt-luna-latest"})
+```
+
+The backend looks up
+`OPENROUTER_API_KEY` when available; credentials are not required at engine
+construction. For the complete inventory and diagnostic defaults see the
+[format reference](../formats.md#bundled-openrouter-configuration). Use
+`promptkit.WithBundledOpenRouter(false)` for application-only inventories.
+Caller records replace matching bundled records in full; use `extends` with a
+distinct ID to inherit. Replacing `auto` also changes its cost-tier children's
+inherited target, while their plugins remain. External collections remain
+supported.
+
 ```go
 promptInputs, err := promptkit.DirectoryInputs("prompts")
 if err != nil { return err }
@@ -152,7 +178,12 @@ input := configkit.Input{Source: document}
 ```
 
 `ProfileSource` and `BackendSource` are smaller typed conveniences when null
-is not needed. Backend and profile definitions are supplied by the caller;
+is not needed. Their provider maps use ConfigKit Mapping input forms: built-in
+scalars, `[]any`, and `map[string]any` recursively. Convert `json.Number` or
+typed containers explicitly to an appropriate supported value, choosing numeric
+precision for your application. Mapping captures supported values immediately;
+unsupported or cyclic values are reported when loaded. Runtime override values
+follow their separate rules. Backend and profile definitions are supplied by the caller;
 there is no registration-only backend namespace.
 
 When configuration or message files change, build and validate a new engine,
@@ -211,7 +242,7 @@ sensitive application data.
 ## Inspect The Captured Configuration
 
 Use [`Engine.InspectConfiguration`](../../configuration_inspection.go) for an
-operator-selected report of composed configuration, source descriptions,
+operator-selected report of resolved configuration, source descriptions,
 diagnostics, and path history. Configuration inspection uses list indexes in
 the collection's nested path rather than qualified runtime IDs. For a profile
 at index `i` in collection `team`, construct the path with `configkit.Keys`:
@@ -230,8 +261,9 @@ if found && explanation.Effective.Redacted {
 the application decides whether those reports may be disclosed. Credential-
 shaped provider keys are redacted, but arbitrary prompt and provider content
 is not necessarily safe to share. Inspection uses the engine's captured result
-and does not reopen sources or resolve credentials. It retains composed values
+and does not reopen sources or resolve credentials. It retains effective values,
-and provenance rather than Promptkit's normalized/defaulted interpretation.
+including recorded field normalization and queue defaulting, alongside source
+provenance.
 `InspectProfile` instead shows backend-completed execution settings for one profile, and `Prepare` or
 `PreparedExecution.Details` shows request-specific rendered messages, inputs,
 and validation resources. None of those views is a substitute for the others.
@@ -263,11 +295,13 @@ for _, difference := range differences {
 ```
 
 See the [`ConfigurationInspection.Diff` GoDoc](../../configuration_inspection.go)
-and ConfigKit's [v1.0.0 effective-configuration diff guidance](https://forge.maximumdirect.net/base-layer/configkit/src/tag/v1.0.0/docs/config.md#effective-configuration-diffs)
+and ConfigKit's [v1.1.0 effective-configuration diff guidance](https://forge.maximumdirect.net/base-layer/configkit/src/tag/v1.1.0/docs/config.md#effective-configuration-diffs)
 for the exact comparison contract. The operation compares only frozen effective
 configuration values: it does not reread external files or compare their
 contents, resolved credential contents, later execution preparation, or
-request-specific overrides. An empty diff is not proof of equivalent execution.
+request-specific overrides. Inputs normalizing to the same effective value do
+not create a value diff; lists are compared atomically. An empty diff is not
+proof of equivalent execution.
 Records can contain ordinary application data, so use the application's
 disclosure policy when presenting them.
 
@@ -662,9 +696,9 @@ the engine to pick up changed definitions or message files.
 ### Choose A Profile Ownership Model
 
 Supply backend and profile definitions through the configuration sources your
-application selects. PromptKit does not install provider catalogs or built-in
+application selects, alongside the default-on bundled OpenRouter inventory.
-profile inventories; conventional backend ID constants are names only. Define
+Conventional backend ID constants are names only. Define or replace the model,
-the model, endpoint, credentials lookup, and settings that your application
+endpoint, credentials lookup, and settings that your application
 intends to support. A profile may inherit a sibling profile by its local key in
 the same root or collection list; its backend reference uses the exact
 configured identity. Caller-selected source layers determine the final values. The
@@ -685,18 +719,19 @@ if err != nil {
 }
 
 target := inspection.EffectiveModelParams
+if inspection.APIKeyRequired {
+	// Arrange a usable direct or configured environment credential.
+}
 if target.APIKeyEnv != "" {
-	// This is a configured optional environment lookup source.
+	// This is the configured environment lookup source, not its value.
-} else if inspection.APIKeyRequired {
-	// Arrange a direct credential before later execution.
 }
 ```
 
 Use this configuration-time boundary when only the profile and its target need
 checking. Use `Prepare` when the application also needs prompt, input, schema,
 or rendering work; use prepared execution when that work must remain tied to a
-later execution. A reported `APIKeyEnv` is a configured optional source, while
+later execution. A reported `APIKeyEnv` identifies a configured source, while
-`APIKeyRequired` is the explicit local requirement. The
+`APIKeyRequired` is the explicit requirement; both may be present. The
 [credential format reference](../formats.md#credentials) and the method's
 [GoDoc](../../engine.go) own the exact precedence, timing, result, and error
 contracts.
@@ -850,6 +885,12 @@ secret-handling policies.
 
 ## Extension Interfaces
 
+JSON Schema validation and native structured output use a self-contained root
+document. Internal references are supported; references to other files or
+network resources fail during preparation. `WithSchemaFile` selects one root
+file, while `WithSchemaFS` and `SchemaDir` select a root source. Prepared
+executions retain their captured schema even if the source later changes.
+
 Inject an [`LLMClient` or `ArtifactReader`](../../types.go) when the built-in
 behavior does not fit the application. Their GoDoc defines concurrent use,
 context handling, ownership of copied values, nil responses, and preservation
@@ -857,6 +898,11 @@ of collaborator errors. Implementations must honor cancellation, safely manage
 copies they retain, avoid unsafe logging of content or credentials, and enforce
 the application policy that motivated the injection.
 
+A successful `ArtifactReader.Read` transfers the returned artifact and mutable
+body storage to Promptkit. Readers that previously reused a returned buffer
+must instead return independent storage and stop mutating it after return;
+private scratch buffers may still be reused when the returned bytes are copied.
+
 ## Handle Errors
 
 Use `errors.Is` with the

docs/development.md

@@ -58,6 +58,14 @@ exist.
 
 ## Maintainer Validation
 
+Use the newest Go installation already available locally for ordinary
+development checks. Put its `bin` directory first on `PATH` and set
+`GOTOOLCHAIN=local` to keep that toolchain selected. For repository-isolated
+checks, set `GOWORK=off`; consumers may use their own workspaces. The selected
+validation patch does not by itself change the module's consumer minimum. See
+the [release toolchain policy](policy/release.md#consumer-minimum-and-release-toolchain)
+and [release procedure](release.md#prepare-the-candidate) for release selection.
+
 For ordinary work, select validation proportionate to the change. Do not repeat
 successful checks for unchanged content merely to create a commit. During
 development, run relevant Go tests and vet, format changed Go files, and execute

docs/formats.md

@@ -6,7 +6,7 @@ This is the canonical reference for Promptkit's backend, profile, prompt, and
 schema definitions. The [Go consumer guide](consumers/pkg-promptkit.md) shows
 how to select sources and use an engine; the
 [OpenAI-compatible integration contract](integrations/openai-compatible-chat.md)
-owns outbound wire behavior. [ConfigKit](https://forge.maximumdirect.net/base-layer/configkit/src/tag/v1.0.0/docs/config.md)
+owns outbound wire behavior. [ConfigKit](https://forge.maximumdirect.net/base-layer/configkit/src/tag/v1.1.0/docs/config.md)
 owns the generic YAML grammar, imports, layering, inheritance, and diagnostics.
 This reference describes what Promptkit does with the final effective values.
 
@@ -14,8 +14,8 @@ A configuration document may contain top-level `backends`, `profiles`, and
 `prompts` lists, plus a `collections` mapping of namespaced resource groups.
 Each resource has an explicit literal `id`, not a filename-derived identity.
 IDs and references must be nonblank and remain exact: Promptkit does not trim or
-re-key them. Unknown fields are errors. Promptkit installs no provider or
+re-key them. Unknown fields are errors. Promptkit installs a default-on bundled
-profile catalog; callers select the definitions they need.
+OpenRouter underlay; callers still explicitly select a profile.
 
 ```yaml
 backends:
@@ -86,9 +86,10 @@ list. It is not a qualified or cross-collection reference.
 no label; an explicitly empty string is retained. It does not select a resource
 or change execution. Runtime lookups
 use the captured effective resource indexes. `InspectConfiguration` is an
-explicit operator view of composed settings and provenance. Normalization and
+explicit operator view of resolved settings and provenance. Selected field
-defaults appear in Promptkit's interpreted execution views, not as changes to
+normalizations and the derived queue default are recorded in that tree, with
-that composed tree. Source history is not a second runtime resolver, and the
+source history retained. Request-time completion remains separate. Source
+history is not a second runtime resolver, and the
 retained effective shape is not flattened or rewritten into those indexes.
 
 For examples of explicitly selecting native collection inputs and inspecting
@@ -331,9 +332,58 @@ For example, a runtime `extra_params["extends"]` key is ordinary provider
 data, not a configuration inheritance instruction. An explicit zero timeout
 does not disable the caller context or HTTP transport timeout.
 
+### Bundled OpenRouter Configuration
+
+The default bundle installs root backend `openrouter`, endpoint
+`https://openrouter.ai/api/v1`, optional credential environment name
+`OPENROUTER_API_KEY`, and smoke metadata selecting `gpt-luna-latest` with the
+`openrouter_key` authentication adapter. Existing diagnostic endpoint fallback
+applies. No prompt, implicit profile selection, or tuning defaults are installed.
+Disable the entire bundle with `WithBundledOpenRouter(false)`.
+
+The root profile IDs and their models are:
+
+| Profile | Model |
+| --- | --- |
+| `gpt-astra-latest` | `~openai/gpt-astra-latest` |
+| `gpt-sol-latest` | `~openai/gpt-sol-latest` |
+| `gpt-terra-latest` | `~openai/gpt-terra-latest` |
+| `gpt-luna-latest` | `~openai/gpt-luna-latest` |
+| `claude-fable-latest` | `~anthropic/claude-fable-latest` |
+| `claude-opus-latest` | `~anthropic/claude-opus-latest` |
+| `claude-sonnet-latest` | `~anthropic/claude-sonnet-latest` |
+| `claude-haiku-latest` | `~anthropic/claude-haiku-latest` |
+| `gemini-pro-latest` | `~google/gemini-pro-latest` |
+| `gemini-flash-latest` | `~google/gemini-flash-latest` |
+| `auto` | `openrouter/auto` |
+| `free` | `openrouter/free` |
+
+The profiles `auto-low`, `auto-medium`, `auto-high`, `auto-xhigh`, and
+`auto-max` extend `auto` and add an `auto-router` plugin with the corresponding
+`cost_tier`. Replacing `auto` changes their inherited backend and model while
+retaining their plugins. These are root IDs even when a model contains `/`.
+For example, a caller can replace `auto` as a complete record and extend another
+bundled profile under a new ID:
+
+```yaml
+profiles:
+  - id: auto
+    backend: openrouter
+    model: openrouter/free
+  - id: my-luna
+    extends: {id: gpt-luna-latest}
+    timeout_seconds: 60
+```
+
+See OpenRouter's [alias examples](https://openrouter.ai/~openai/gpt-luna-latest),
+[auto router and cost tiers](https://openrouter.ai/docs/guides/routing/routers/auto-router),
+and [free router](https://openrouter.ai/docs/guides/routing/routers/free-router)
+for provider behavior and availability.
+
 ### Source And Profile Precedence
 
-`NewEngine` composes caller underlays in their given order, followed by an
+`NewEngine` composes the bundled OpenRouter underlay first by default, then
+caller underlays in their given order, followed by an
 optional main input. Later layers overlay earlier ones. Inputs within one
 underlay group are strictly composed: conflicting contributions are errors,
 not priority signals. The directory helpers discover `.yaml` and `.yml` files recursively
@@ -363,16 +413,22 @@ references are exact IDs and use their qualified form when they select a
 collection resource. There is no Promptkit-specific depth limit or second
 base-chain resolver. Missing references and cycles fail at construction. For
 generic inheritance and layer mechanics, consult
-[ConfigKit](https://forge.maximumdirect.net/base-layer/configkit/src/tag/v1.0.0/docs/config.md).
+[ConfigKit](https://forge.maximumdirect.net/base-layer/configkit/src/tag/v1.1.0/docs/config.md).
 
 ## Schemas
 
 Schemas are JSON documents selected by a prompt or request `schema_path`.
-Directory and `fs.FS` schema paths resolve within the configured root;
+Directory and `fs.FS` schema paths resolve within the configured root. Each
-referenced nested schemas resolve relative to the owning schema document.
+schema must be self-contained: in-document references, IDs, and anchors are
+supported, but references requiring another file or network resource fail.
+References must also work without the source filename as a base; use fragment
+references or explicit schema IDs rather than relying on that filename.
 `WithSchemaFile` exposes one schema under its base name. An unreadable,
 invalid, or unresolvable schema causes an operational validation error.
 Valid JSON that fails the schema instead yields a failed validation result.
+Schema documents are detached without applying the provider extra-parameter
+copy limits; this does not change the schema decoder, compiler, or
+self-contained-resource rules.
 
 ## Credentials
 

docs/integrations/openai-compatible-chat.md

@@ -16,14 +16,13 @@ Generation sends an HTTP `POST` with `Content-Type: application/json`.
 Before the client is called, the engine resolves framework, backend, profile,
 and request values into one execution target. Endpoint configuration is trimmed
 and must be an absolute HTTP or HTTPS URL with a host and without user
-information, a query, or a fragment. A non-empty endpoint from the target
+information, a query, or a fragment. The target's endpoint is validated again
-overrides the client's configured base URL. The final selected endpoint is
+before transport.
-validated again before transport.
 
 The completion URL is composed through parsed URL path operations. Nested base
 paths are retained, repeated trailing slashes are normalized, and the result
 has exactly one appended `/chat/completions` suffix. Generation fails before
-sending when neither source supplies a valid endpoint.
+sending when the target does not supply a valid endpoint.
 
 The target's backend ID is routing metadata for prepared values, results, and
 injected clients. The built-in client does not derive the URL from that ID and
@@ -70,7 +69,9 @@ and numeric `usage`; unrelated fields and account limits are ignored. This is
 only a minimal identifying subset of OpenRouter's documented
 [current-key response](https://github.com/OpenRouterTeam/docs/blob/main/api_reference/limits.mdx#checking-your-limits),
 not validation of the full account document. Other statuses and unrecognized
-200 responses do not establish acceptance.
+200 responses do not establish acceptance. A 200 response exceeding the bounded
+recognition allowance reports `authentication_response_limit_exceeded`, leaving
+credential acceptance unknown; see the [public reason](../../smoke_diagnostics.go).
 
 Diagnostic HTTP evidence describes the last request observed at Promptkit's
 RoundTripper boundary and any response associated with it. It includes the
@@ -87,8 +88,7 @@ transport for HTTP-only diagnostics.
 ## Request Body
 
 The request body always contains `model` and `messages`. The execution
-target's model takes precedence over the client's configured model, and one
+target's model must be available.
-must be available.
 
 Each ordinary message contains its `role` and string `content`. A
 cache-controlled message instead uses a text content block containing `type`,
@@ -115,9 +115,10 @@ The client conditionally includes:
   strict flag, and schema document. Plain JSON validation does not add an
   object-only response constraint.
 
-The engine resolves backend, profile, and request extra-parameter maps by
+Configured profile maps recursively overlay backend defaults, while a nonempty
-whole-map replacement rather than key merging. The resulting effective map is
+runtime override replaces the complete configured map. The [format reference](../formats.md#defaults-and-overrides)
-merged into the top-level body. Empty keys, values that cannot be encoded, and
+owns these resolution rules. The resulting effective map is merged into the
+top-level body. Empty keys, values that cannot be encoded, and
 collisions with these reserved fields are rejected before any provider call:
 
 - `model`

docs/internal/capacity.md

@@ -68,9 +68,8 @@ Preparation and validation never hold an active permit.
 
 The manager's `Acquire` operation owns that active-permit acquisition and
 returns an idempotent release function. The coordinator uses it around
-individual attempts. The earlier one-shot wrapper still delegates to the same
+individual attempts. There is one queue and one active limit per limited backend
-operation for focused internal callers and tests, but engine assembly no
+pool.
-longer uses it. There is one queue and one active limit per limited backend pool.
 
 When all active permits are occupied, calls join a mutex-protected FIFO waiter
 list. Releasing a permit transfers it directly to the oldest remaining waiter
@@ -121,7 +120,7 @@ validation, bounded admission, idempotent release, context handling, and
 unlimited admission. The
 [client tests](../../internal/capacity/client_test.go) own peak enforcement,
 FIFO transfer, canceled-waiter removal, grant/cancel races, independent pools,
-unlimited calls, passthrough behavior, and panic release.
+unlimited calls, and panic release using test-only one-shot calls.
 
 The [runner tests](../../internal/usecase/runner_test.go) own ordinary early
 admission, lease lifetime, failure release, and shared initial/repair

docs/internal/llm.md

@@ -26,10 +26,9 @@ client uses its endpoint, credential metadata, generation fields, and extra
 parameters. `BackendID` remains routing metadata
 for the generation boundary and is not mapped into the provider payload.
 
-Construction trims and validates a nonempty configured base URL and clones any
+Construction clones any supplied `http.Client` so Promptkit can apply its
-supplied `http.Client` so Promptkit can apply its timeout default without
+timeout default without mutating the caller's client. Generation preparation
-mutating the caller's client. An empty configured base remains valid because a
+then:
-resolved request target may supply the endpoint. Generation preparation then:
 
 1. validates shared execution-setting invariants and the final selected base
    endpoint;
@@ -42,6 +41,10 @@ resolved request target may supply the endpoint. Generation preparation then:
    the complete-request failure remains a request failure;
 6. resolves authentication and freezes the URL, body, and optional credential.
 
+Provider values are detached with trusted copying before encoding. Custom JSON
+encoding methods and per-value encoding-failure diagnostics operate on those
+private copies rather than retained prepared or diagnostic metadata.
+
 Each execution of that prepared request creates a fresh HTTP request, body
 reader, and attempt timeout context. It closes the response body and returns
 the HTTP status, decoded response or error, reported token values and presence,
@@ -77,7 +80,8 @@ not retain headers, credentials, raw request or response bodies, or a redirect
 trace. These are observations at Promptkit's RoundTripper boundary, not proof
 that bytes reached a peer or that a custom transport did no hidden dispatch.
 Reachability and named authentication probes use the same configured built-in
-client but discard their response bodies after local recognition. The
+client. The OpenRouter adapter owns endpoint derivation, bounded account-response
+recognition, and body closure; the smoke coordinator interprets its evidence. The
 [integration contract](../integrations/openai-compatible-chat.md#explicit-smoke-diagnostics)
 owns their observable HTTP semantics.
 
@@ -105,14 +109,13 @@ public ownership and redaction semantics belong to the
 
 ## Failure Categories
 
-The package preserves distinct error identities for invalid client
+The package preserves distinct error identities for invalid generation
-configuration, invalid generation requests, request execution failures,
+requests, request execution failures, non-success provider statuses, and
-non-success provider statuses, and malformed successful responses. Provider
+malformed successful responses. Provider response bodies are never exposed in
-response bodies are never exposed in raw form through non-success errors.
+raw form through non-success errors.
 
-Invalid nonempty configured endpoints are configuration failures. A missing or
+A missing or invalid final selected endpoint is an invalid generation request
-invalid final selected endpoint is an invalid generation request and is
+and is rejected before transport.
-rejected before transport.
 
 Authentication resolves a trimmed direct key before a trimmed configured
 environment value. Optional missing, empty, or whitespace-only sources do not

docs/internal/observation.md

@@ -10,6 +10,10 @@ lifecycle instrumentation spans the facade and runner boundaries.
 Prepared execution starts only after its private payload is atomically claimed;
 the facade receives that invocation's recorder privately and emits the terminal
 event after public error mapping. Failed claims and preparation emit nothing.
+The public projection retains private operation-owner metadata separately from
+inspectable child causes. Terminal classification uses that owner, preserving
+context precedence and generation-specific transport/provider details rather
+than mistaking a collaborator's nested lookup error for the parent's operation.
 
 The facade masks inherited recorder and prepared-claim state when entering
 preparation or execution. Delegated calls from an injected collaborator retain

docs/internal/overview.md

@@ -23,7 +23,7 @@ contributor workflow and validation.
 | `internal/generation` | Coordinates frozen built-in HTTP attempts and one-shot injected calls through active backend permits, including bounded status retries, cancellable backoff, ordinary attempt observations, and invocation-local evidence for diagnostics. | [Internal generation coordination](generation.md) |
 | `internal/defaults` | Defines application-neutral framework constants and constructs the default execution target. It contains no CLI, server, or inbound HTTP limits. | [Framework defaults](../../internal/defaults/defaults.go) |
 | `internal/filecatalog` | Provides deterministic YAML discovery and path helpers for operating-system filesystems and `fs.FS` sources. | [File catalog](../../internal/filecatalog/catalog.go) |
-| `internal/jsonvalue` | Validates and deeply copies bounded JSON-compatible extra-parameter and prepared-schema trees while preserving supported concrete value types and rejecting cycles or excessive depth and work. | [JSON values](../../internal/jsonvalue/jsonvalue.go) |
+| `internal/jsonvalue` | Validates and deeply copies bounded JSON-compatible provider values, and detaches previously accepted values without repeating validation. | [JSON values](../../internal/jsonvalue/jsonvalue.go) |
 | `internal/promptdef` | Provides a narrow captured-prompt lookup contract, not-found identity, and execution-ready definition hash. | [Prompt lookup](../../internal/promptdef/repository.go), [framework formats](../formats.md) |
 | `internal/profile` | Provides a narrow captured-profile lookup contract and not-found identity. | [Profile lookup](../../internal/profile/repository.go), [framework formats](../formats.md) |
 | `internal/prompt` | Renders prompt messages from Go templates with artifact, variable, session, and cache-control data, and conservatively enumerates dependencies from captured template syntax. | [Go-template renderer](../../internal/prompt/go_renderer.go), [requirement discovery](../../internal/prompt/requirements.go) |

docs/internal/runner.md

@@ -42,10 +42,11 @@ Ordinary preparation selects the full prompt definition and construction-time
 hash. It retains its early request-ID check before direct-session
 normalization. Referenced message content and static template syntax were
 captured when the engine was built.
+Rendering uses those captured parses, cloning them per call to bind request
+input helpers; it does not parse templates during execution.
 
-`InspectPrompt` selects captured metadata through an optional repository
+`InspectPrompt` selects captured metadata directly from the repository. It
-capability, falling back to the full definition and existing hash resolution
+returns owned metadata without
-for internal repositories without it. It returns owned metadata without
 rendering templates or touching profile, artifact, schema, renderer, validator,
 admission, or model collaborators. The root
 [`Engine.InspectPrompt`](../../engine.go) GoDoc owns the public operation's
@@ -57,8 +58,7 @@ snapshot by the selected prompt ID. The analyzer receives only
 those identity fields rather than an execution definition. It analyzes the
 snapshot with the supplied caller variables and normalized direct-session
 bypass; it does not resolve target readiness or enter the preparation
-pipeline. Missing snapshot capability is a prompt-load failure rather than a
+pipeline. An unavailable captured snapshot is a prompt-load failure. The root
-source fallback. The root
 [`Engine.InspectRequirements`](../../requirements.go) GoDoc owns the public
 operation's exact contract.
 
@@ -142,11 +142,10 @@ one execution-precedence and error-ordering implementation while allowing a
 full backend pool to reject work before expensive schema, artifact, and
 rendering operations. `Prepare` discards the plan after returning its public
 metadata. `Run` retains the plan through initial and repaired-output validation
-and discards it when the operation ends. Prepared execution transfers the
+and discards it when the operation ends. Prepared execution retains one
-completed preparation's owned message, input-hash, and copied-schema values
+immutable, redacted metadata snapshot shared by execution and internal details.
-into its private payload, while deep-copying mutable provider extras and
+The facade detaches mutable public details. Claim completion or discard clears
-creating an independent details snapshot. Claim completion or discard clears
+execution-only payload references without modifying the retained metadata.
-the execution payload without removing the details snapshot.
 
 The root facade's `Engine.ValidateRequest` uses the same complete preparation
 path as `Prepare` and discards the resulting internal prepared value without
@@ -176,7 +175,7 @@ encoding of that session, every role and content value, and cache-control
 presence and values; its hexadecimal value is opaque.
 
 The configuration snapshot is read-only after engine construction. Concurrent
-`Prepare` and `Run` calls copy their resolved targets and keep all invocation
+`Prepare` and `Run` calls use detached captured targets and keep invocation
 state local.
 
 ## Run Flow

docs/internal/sources.md

@@ -12,13 +12,12 @@ source semantics. Internal packages are not consumer APIs.
 
 `internal/configuration` is the single adapter from ConfigKit's final
 effective configuration to execution-owned definitions. It performs one
-layered load, captures effective presence (including explicit null), builds
+layered load, captures effective presence (including explicit null), records
-detached normalized interpretations during validation, and validates all effective
+field-level normalization and derived defaults during resolution, and validates all effective
 root and collection backend, profile, and prompt values. Replaced lower-layer
 domain values are not separately validated. It indexes root resources under
 their unqualified IDs and collection resources under their full
-`namespace/local-key` IDs while retaining ConfigKit's effective tree in its
+`namespace/local-key` IDs while retaining ConfigKit's resolved tree. It builds an immutable backend index and presence-aware profile
-authored shape. It builds an immutable backend index and presence-aware profile
 targets, applying final backend defaults only after profile inheritance. Runtime
 lookups use those final indexes and exact stored references; they do not rewrite
 or resolve resources from ConfigKit source history. The runtime/domain packages
@@ -27,7 +26,7 @@ do not depend on ConfigKit.
 ConfigKit owns source headers, imports, composition, and source evidence.
 Promptkit does not preparse contributions: it validates the final effective
 values once, captures the indexed identities and their original resource
-contexts, and retains ConfigKit's composed result for explicit operator inspection.
+contexts, and retains ConfigKit's resolved result for explicit operator inspection.
 Accepted non-main source headers are consumed during composition; the main
 source declaration remains available in that inspection view. Collection
 release labels are descriptive metadata, not selection inputs. The
@@ -37,12 +36,12 @@ owns the exact source-header and collection contracts.
 The `ConfigurationInspection.Diff` facade method compares two retained results
 through a private wrapper and a narrow `internal/configuration.Diff` bridge.
 The wrapper keeps `Result[document]` inside the adapter; the bridge delegates
-once to ConfigKit v1.0.0 and returns its public difference records. Comparison
+once to ConfigKit v1.1.0 and returns its public difference records. Comparison
 uses only frozen effective values and does not reopen sources, resolve runtime
 credentials, or enter the execution path. ConfigKit applies sensitivity from
 both results; reports may still contain ordinary application data. See the
 [consumer comparison guide](../consumers/pkg-promptkit.md#inspect-the-captured-configuration)
-and ConfigKit's [v1.0.0 comparison contract](https://forge.maximumdirect.net/base-layer/configkit/src/tag/v1.0.0/docs/config.md#effective-configuration-diffs).
+and ConfigKit's [v1.1.0 comparison contract](https://forge.maximumdirect.net/base-layer/configkit/src/tag/v1.1.0/docs/config.md#effective-configuration-diffs).
 
 After resource materialization and effective-profile snapshot construction, the
 adapter captures lexically ordered identity inventories for backends, profiles,
@@ -53,7 +52,9 @@ captured values without consulting ConfigKit or copying resource definitions.
 The root `DirectoryInputs` and `FilesystemInputs` helpers discover sorted YAML
 files under an explicit root, provide resource context, and leave imports
 disabled. Each returned slice belongs to one strict-composition group; file
-order does not confer priority. Caller underlays are composed in their given
+order does not confer priority. Engine assembly prepends a dedicated embedded
+OpenRouter underlay unless disabled, without modifying caller-owned slices.
+Caller underlays are composed in their given
 order, followed by the optional main input. The
 [configuration tests](../../internal/configuration/load_test.go) exercise the
 real loader and final-value handoff.
@@ -84,13 +85,14 @@ returning and retains no source capability for public inspection.
 
 Prompt materialization shares a lazy metadata snapshot across root and collection
 resources during construction, avoiding a full metadata copy per collection.
+Input metadata, message content and templates, and output contracts are captured
+separately before the definition, inspection, and hash are assembled.
 
-Normalization and defaults are applied to execution-owned interpretations,
+Normalization and defaults are recorded at individual resolved field paths,
-including message roles and cache controls. ConfigKit retains the composed
+including message roles and cache controls. List indexes identify fields for
-values and origins, rather than synthetic Promptkit normalization events. List
+presence, validation, sensitivity, and resource context; full IDs select
-indexes identify fields for presence, validation, sensitivity, and resource
+captured runtime indexes. Unchanged content-file fields retain their origins.
-context; full IDs select captured runtime indexes. Recording a sequence-wide
+Backend-to-profile and request-time completion remain separate runtime work.
-normalization would replace origins of unchanged content-file fields.
 
 The runner selects full definitions from this index for preparation and uses
 captured prompt metadata for `InspectPrompt` and `InspectRequirements`; the
@@ -146,8 +148,8 @@ change rendering behavior.
 ConfigKit resolves profile inheritance before the handoff. Within a collection,
 `extends: {id: parent}` names a sibling local ID; it is not a cross-collection reference.
 The configuration adapter validates final effective resource references and
-field values, then builds target
+field values, then captures backend definitions and profile target snapshots
-snapshots with backend defaults and presence/suppression state. A profile can
+with backend defaults and presence/suppression state. A profile can
 remain partial until runtime overrides complete it. `InspectProfile` selects
 that captured target without prompt, artifact, schema, credential lookup, or
 provider work. Preparation applies runtime overrides and then checks target
@@ -216,12 +218,14 @@ instead of first making a response-sized string copy.
 
 Every preparation operation creates one operation-local validation plan. None,
 basic, and JSON modes retain the effective output contract without source
-access. JSON Schema mode loads the root document once, resolves and compiles
+access. JSON Schema mode loads the root document once, compiles its declared
-each transitive reference, and retains the compiled validator. Schema compiler
+schema locations, and retains the compiled root validator. External resources
-resources use canonical escaped file or private-scheme URLs; loaders decode
+are rejected without file or network loading; in-document references remain
-their paths once and enforce the configured source boundary. The
+supported. Root resources use canonical escaped file or private-scheme URLs. The
 provider-facing structured-output metadata uses the root document captured by
-the same plan.
+the same plan. Its detached schema document is not revalidated against the
+runtime provider-value copier's traversal limits. Smoke inference uses a
+separate JSON-only prepared plan before checking the prepared schema plan.
 
 Schema preparation and execution remain synchronous. Promptkit checks
 cancellation before and after source resolution, JSON decoding, compilation,

docs/oss/attribution.md

@@ -26,17 +26,31 @@ License and notices: [CC BY-SA 4.0](licenses/CC-BY-SA-4.0.txt) |
 
 ## ConfigKit
 
-Selected module: `go.maximumdirect.net/configkit` at `v1.0.0`.
+Selected module: `go.maximumdirect.net/configkit` at `v1.1.0`.
 
 Copyright (C) 2026 Eric Rakestraw
 
 SPDX-License-Identifier: LGPL-3.0-or-later
 
 License and notices: [LGPL 3.0](../../LICENSE) |
-[COPYRIGHT](https://forge.maximumdirect.net/base-layer/configkit/src/commit/c88aac990b23f48a31f9046b830d4d0954f57f53/COPYRIGHT) |
+[COPYRIGHT](https://forge.maximumdirect.net/base-layer/configkit/src/commit/191015e289d7f2b91abb9fdd9c4f2f5cf75b4de9/COPYRIGHT) |
-[LICENSE](https://forge.maximumdirect.net/base-layer/configkit/src/commit/c88aac990b23f48a31f9046b830d4d0954f57f53/LICENSE).
+[LICENSE](https://forge.maximumdirect.net/base-layer/configkit/src/commit/191015e289d7f2b91abb9fdd9c4f2f5cf75b4de9/LICENSE).
 
-[Source](https://forge.maximumdirect.net/base-layer/configkit/src/commit/c88aac990b23f48a31f9046b830d4d0954f57f53).
+[Source](https://forge.maximumdirect.net/base-layer/configkit/src/commit/191015e289d7f2b91abb9fdd9c4f2f5cf75b4de9).
+
+## ReleaseKit
+
+Selected module: `go.maximumdirect.net/releasekit` at `v0.9.0` (maintainer tool).
+
+Copyright (C) 2026 Eric Rakestraw
+
+SPDX-License-Identifier: LGPL-3.0-or-later
+
+License and notices: [LGPL 3.0](../../LICENSE) |
+[COPYRIGHT](https://forge.maximumdirect.net/base-layer/releasekit/src/commit/2180aa868ec2caa95fc8279fd59d5f0ebac41bd4/COPYRIGHT) |
+[LICENSE](https://forge.maximumdirect.net/base-layer/releasekit/src/commit/2180aa868ec2caa95fc8279fd59d5f0ebac41bd4/LICENSE).
+
+[Source](https://forge.maximumdirect.net/base-layer/releasekit/src/commit/2180aa868ec2caa95fc8279fd59d5f0ebac41bd4).
 
 ## jsonschema
 

docs/release.md

@@ -74,8 +74,8 @@ Successful publication needs no separate remote read-back or CI wait.
 
 For optional local diagnosis, use `./scripts/releasekit.sh check VERSION`.
 It is not a required step before publication. The upstream
-[candidate-check guide](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.8.0/docs/consumers/check.md)
+[candidate-check guide](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.9.0/docs/consumers/check.md)
-and [CLI contract](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.8.0/docs/cli.md)
+and [CLI contract](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.9.0/docs/cli.md)
 own shared checks and exit-status definitions.
 
 ## Deliver The Hosted Release
@@ -97,14 +97,26 @@ For a later retry, use a clean checkout of the original tag with its recorded
 module files and supply the token there. In a separate checkout, for example:
 
 ```sh
-git switch --detach vMAJOR.MINOR.PATCH
+(
-./scripts/releasekit.sh deliver vMAJOR.MINOR.PATCH
+  set -e
+  release_version=vMAJOR.MINOR.PATCH
+  release_tag_ref="refs/tags/$release_version"
+  git fetch origin "$release_tag_ref:$release_tag_ref"
+  release_tag_commit=$(git rev-parse --verify "$release_tag_ref^{commit}")
+  git switch --detach "$release_tag_commit"
+  release_worktree_status=$(git status --porcelain --untracked-files=all)
+  if [ -n "$release_worktree_status" ]; then
+    printf '%s\n' 'Delivery retry requires a clean tagged checkout.' >&2
+    exit 1
+  fi
+  ./scripts/releasekit.sh deliver "$release_version"
+)
 ```
 
 Resolve uncertain hosted writes before retrying the same immutable version.
 Matching content is accepted; conflicts are not overwritten. Do not rerun
 `publish` or move tags to repair delivery. Follow the upstream
-[delivery guide](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.8.0/docs/consumers/delivery.md)
+[delivery guide](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.9.0/docs/consumers/delivery.md)
 for result interpretation and recovery. These commands apply to tags containing
 this delivery configuration; older releases retain their original workflows.
 
@@ -131,13 +143,13 @@ and explicitly select the matching attempt:
 Discovery is local; reconciliation observes the original destination without
 rerunning validation, changing tags, or delivering hosted content. Neither is
 a routine gate after successful publication. Follow the upstream
-[recovery procedure](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.8.0/docs/release.md#resolve-publication-failures)
+[recovery procedure](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.9.0/docs/release.md#resolve-publication-failures)
 for outcomes, incomplete evidence, and older attempts without records.
 
 Records are stored under Git's common directory by default and can contain
 credential-bearing endpoints. Keep them private, out of source control and
 shared logs; retain them while needed for recovery and remove them when that
-value expires. See the [evidence guide](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.8.0/docs/consumers/publish.md#retain-and-reconcile-publication-evidence)
+value expires. See the [evidence guide](https://forge.maximumdirect.net/base-layer/releasekit/src/tag/v0.9.0/docs/consumers/publish.md#retain-and-reconcile-publication-evidence)
 for storage and retention details.
 
 Current absence does not prove a version was never published. Remove a retained

docs/releases/v0.18.0.md

@@ -0,0 +1,65 @@
+# Promptkit v0.18.0
+
+Configuration inspection now exposes Promptkit's recorded field normalization
+and derived queue-capacity defaults through ConfigKit v1.1.0. Engines also
+include a default-on OpenRouter configuration. The minimum supported Go
+version remains 1.27.0.
+
+## Bundled OpenRouter Backend And Profiles
+
+New engines include an embedded OpenRouter backend and seventeen root profiles:
+ten latest-family aliases, the auto and free routers, and five auto-router
+cost-tier variants. Select a profile explicitly in a prompt or request; the
+bundle does not supply an implicit execution profile or contact providers
+during construction. The backend uses `OPENROUTER_API_KEY` when available under
+the existing optional-credential rules.
+
+The bundle is the lowest-priority underlay. Applications can replace its records
+or derive named variants through ordinary configuration, and external collections
+remain supported. Cost-tier variants inherit the effective `auto` profile, so
+replacing that parent changes their inherited target while retaining plugins.
+The [bundle reference](../formats.md#bundled-openrouter-configuration) owns the
+inventory and composition details.
+
+Explicit smoke diagnostics now have OpenRouter authentication metadata and an
+inference fallback profile. They remain opt-in and may incur provider costs.
+Latest aliases and routers can change upstream; configured slugs do not pin
+the concrete model, pricing, or availability. See the
+[consumer guide](../consumers/pkg-promptkit.md#construct-an-engine) for selection
+and opt-out examples.
+
+## Recorded Configuration Normalization
+
+Inspection shows normalized backend and profile settings, prompt metadata, and
+configured message roles and cache controls, with field-level resolution
+history. Existing source evidence remains available, and unchanged content-file
+origins continue to select their resource context.
+
+Configuration diffs compare normalized effective values, so spelling-only
+changes that normalize identically may no longer appear. Lists remain atomic in
+diffs. Inspection does not include backend-to-profile completion or request
+overrides; see the [configuration inspection guide](../consumers/pkg-promptkit.md#inspect-the-captured-configuration).
+
+## Compatibility And Upgrade
+
+New engines install a bundled OpenRouter backend and root profiles by default.
+Inventory listings and inspection sources therefore change, and references to
+bundled IDs that previously failed may now resolve. Pass
+`promptkit.WithBundledOpenRouter(false)` to retain application-only behavior.
+Caller records can replace bundled definitions through ordinary composition;
+same-ID replacements replace complete records rather than merging selected fields.
+No configuration-format migration is required from v0.17.0.
+Consumers that display or compare configuration inspection results should account
+for normalized values and derived defaults replacing their earlier authored
+representations. Request-time overrides and caller-appended messages retain
+their existing processing.
+
+```sh
+go get go.maximumdirect.net/promptkit@v0.18.0
+```
+
+See the [framework format reference](../formats.md) for current configuration
+semantics. Consumers upgrading from versions before v0.17.0 should also follow
+the [configuration and API migration guide](../consumers/configuration-migration.md).
+
+[COPYRIGHT](https://forge.maximumdirect.net/base-layer/promptkit/src/tag/v0.18.0/COPYRIGHT) | [LICENSE](https://forge.maximumdirect.net/base-layer/promptkit/src/tag/v0.18.0/LICENSE) | [ATTRIBUTION](https://forge.maximumdirect.net/base-layer/promptkit/src/tag/v0.18.0/docs/oss/attribution.md)

docs/releases/v0.19.0.md

@@ -0,0 +1,80 @@
+# Promptkit v0.19.0
+
+This release completes two rounds of audit remediation, correcting error and
+diagnostic reporting and simplifying configuration, validation, and value
+ownership. It includes intentional compatibility changes for custom artifact
+readers, programmatic configuration sources, and schemas. The minimum supported
+Go version remains 1.27.0; ConfigKit remains at v1.1.0.
+
+## Compatibility And Upgrade
+
+Consumers upgrading from v0.18.0 should review these changes:
+
+- A successful `ArtifactReader.Read` transfers ownership of the returned
+  artifact and its mutable body storage to Promptkit. Custom readers must stop
+  mutating returned values through retained aliases. Readers that reuse scratch
+  buffers must return independent storage. Promptkit retains its defensive
+  body copy, but that copy does not make concurrent buffer reuse safe. See the
+  [extension guidance](../consumers/pkg-promptkit.md#extension-interfaces).
+- Provider maps passed through `ProfileSource` and `BackendSource` now use
+  ConfigKit's native Mapping input forms directly: built-in scalars, `[]any`,
+  and `map[string]any` recursively. Convert `json.Number` and typed containers
+  explicitly to supported values, choosing numeric precision appropriate to
+  the application. The former recursive compatibility conversion is removed.
+  Runtime execution overrides retain their separate accepted-value behavior.
+- Schemas used for local validation and native structured output must be
+  self-contained. Move externally referenced definitions into the root document
+  and use internal references or explicit schema IDs. References requiring
+  another file or network resource, or relying on the source filename as a base,
+  fail during preparation. Promptkit does not bundle external schemas. See the
+  [schema reference](../formats.md#schemas).
+
+Prepared schemas no longer inherit the depth and node limits used when copying
+runtime provider values. Schemas previously rejected solely by those incidental
+limits may now be accepted; decoder/compiler checks and the self-contained
+schema requirement still apply.
+
+No configuration-format migration is required from v0.18.0. After addressing
+any affected integrations:
+
+```sh
+go get go.maximumdirect.net/promptkit@v0.19.0
+```
+
+## Errors And Diagnostics
+
+Public errors and terminal observations now preserve the category of the
+operation that failed even when an injected collaborator returns an error from
+another Promptkit operation. Underlying causes remain available through
+`errors.Is` and `errors.As`, without repeatedly duplicating nested cause trees.
+
+Built-in generation preserves response-body read failures separately from
+malformed response content, and failures during request preparation are
+distinguished from dispatched attempts.
+
+OpenRouter authentication diagnostics bound response recognition to 1 MiB.
+An oversized HTTP 200 response reports
+`SmokeTestReasonAuthenticationResponseLimitExceeded`, leaving credential
+acceptance unknown. Cancellation during the read remains an interruption.
+Consumers that enumerate diagnostic reasons should handle the new reason;
+see the [diagnostic integration contract](../integrations/openai-compatible-chat.md#explicit-smoke-diagnostics).
+
+## Internal Simplification And Ownership
+
+Prompt lookup and rendering now consistently use captured configuration, and
+smoke syntax and schema checks share the prepared output-validation lifecycle.
+Unused routing defaults, alternate private workflows, and duplicate wire
+representations have been removed.
+
+Provider-setting resolution, inspection, prepared details, and smoke reports
+avoid redundant validation and copying of already accepted values. Prepared
+execution shares one private redacted metadata snapshot while preserving
+independent caller-visible values. Provider values are detached before custom
+JSON encoders run, protecting retained metadata from encoder-side mutation.
+
+Requirement analysis, namespace-filtered listings, and repair-feedback
+construction also avoid unnecessary traversal and temporary allocation. These
+changes preserve existing request isolation and execution behavior without
+introducing new performance guarantees.
+
+[COPYRIGHT](https://forge.maximumdirect.net/base-layer/promptkit/src/tag/v0.19.0/COPYRIGHT) | [LICENSE](https://forge.maximumdirect.net/base-layer/promptkit/src/tag/v0.19.0/LICENSE) | [ATTRIBUTION](https://forge.maximumdirect.net/base-layer/promptkit/src/tag/v0.19.0/docs/oss/attribution.md)

docs/roadmap/future.md

@@ -38,30 +38,17 @@ consumers.
 
 ## Ideas
 
-### Field-Level Normalization With Preserved List Provenance
+### Schema Bundling
 
-Reevaluate normalizing resource fields directly in ConfigKit's effective
+Allow consumers to author reusable schemas across multiple files and package
-configuration after upstream ConfigKit supports recording changes within a
+them into a single self-contained schema for local validation and provider
-list without replacing the source attribution of unchanged fields.
+submission. This could restore multi-file authoring convenience while retaining
+the [self-contained schema requirement](../formats.md#schemas).
 
-This could let configuration inspection show PromptKit-normalized values and
+Bundling would need to preserve reference semantics, identifiers, anchors, and
-field-level change history while preserving the origins needed to resolve
+recursion. A complete bundle would not guarantee that a provider supports every
-relative resources such as `content_file`. Assess whether that inspection
+schema feature. This is a possible future enhancement; implementation is not
-benefit justifies changing the execution-owned normalization approach.
+currently approved.
-
-Include normalization of roles and cache-control values in configured messages
-in this reevaluation. This could make inspection reflect the values used for
-execution and reduce separate normalization paths. Upstream support would need
-to preserve untouched field origins within nested message lists as well as outer
-resource lists. PromptKit would continue owning the normalization rules;
-ConfigKit would record their effects and provenance. Caller-appended messages
-would still need request-time normalization because they do not pass through
-ConfigKit.
-Consider moving these transformations only if it improves inspection consistency
-and simplifies implementation without changing execution behavior.
-
-Upstream support is the reconsideration trigger, not a dependency of the
-current ConfigKit migration or a commitment to adopt the enhancement.
 
 ## Entry Format
 

engine.go

@@ -101,8 +101,9 @@ type Engine struct {
 }
 
 // ConfigurationSources selects ordered ConfigKit underlays and an optional
-// highest-priority main input. Each underlay's inputs strictly compose within
+// highest-priority main input. By default a bundled OpenRouter underlay precedes
-// their group; later underlays overlay earlier ones. A nil Main uses
+// the caller underlays; [WithBundledOpenRouter] can disable it. Inputs within
+// each underlay strictly compose; later underlays overlay earlier ones. A nil Main uses
 // ConfigKit's empty source. A non-nil Main is passed through unchanged and
 // may fail construction if invalid.
 type ConfigurationSources struct {
@@ -154,6 +155,15 @@ type engineOptions struct {
 	internal internalengine.Options
 }
 
+// WithBundledOpenRouter enables or disables the built-in OpenRouter underlay.
+// It is enabled by default; when repeated, the last option wins.
+func WithBundledOpenRouter(enabled bool) Option {
+	return optionFunc(func(options *engineOptions) error {
+		options.internal.SetBundledOpenRouter(enabled)
+		return nil
+	})
+}
+
 // WithLLMClient replaces the built-in model client used by [Engine.Run] and
 // [Engine.RunPrepared].
 //
@@ -203,7 +213,8 @@ func WithSchemaFS(fsys fs.FS, root string) Option {
 //
 // Prompt schema_path values refer to the file's base name. path must name an
 // existing non-directory file when NewEngine applies the option. This option
-// replaces Config.SchemaDir and earlier schema-source options.
+// replaces Config.SchemaDir and earlier schema-source options. The selected
+// schema must be self-contained; external resources are not loaded.
 func WithSchemaFile(path string) Option {
 	return optionFunc(func(options *engineOptions) error {
 		return options.internal.SetSchemaFile(path)
@@ -213,7 +224,9 @@ func WithSchemaFile(path string) Option {
 // NewEngine constructs an Engine from configuration and options.
 //
 // ConfigKit composes caller-selected underlays in their given order, followed
-// by the optional main input. Construction validates the final effective
+// by the optional main input, after the default-on bundled OpenRouter underlay.
+// The bundle adds a root backend and profiles to inventories, but no prompts
+// or implicit profile selection. Construction validates the final effective
 // backend, profile, and prompt definitions and captures referenced prompt
 // content. A missing prompt collection is allowed. Schema documents and
 // request artifacts remain runtime resources.
@@ -299,8 +312,8 @@ func (e *Engine) InspectPrompt(
 // override. BackendID is empty for an endpoint-only profile.
 //
 // APIKeyEnv in the returned target is an environment-variable name, never its
-// value. APIKeyRequired instead reports a direct credential requirement and is
+// value. APIKeyRequired reports that a credential is required; an explicit
-// mutually exclusive with a nonblank APIKeyEnv. InspectProfile neither derives
+// profile environment source can also be present. InspectProfile neither derives
 // an ID from a prompt default_profile nor checks credential availability, so an
 // absent or blank named environment variable is not an error.
 //

errors.go

@@ -13,10 +13,44 @@ import (
 	"go.maximumdirect.net/promptkit/internal/usecase"
 )
 
+// publicOperationError keeps classification separate from inspectable causes.
+// Cache wording so formatting nested operations does not repeatedly rebuild it.
+type publicOperationError struct {
+	owner   error
+	cause   error
+	message string
+}
+
+func (e *publicOperationError) Error() string        { return e.message }
+func (e *publicOperationError) Unwrap() error        { return e.cause }
+func (e *publicOperationError) Is(target error) bool { return errors.Is(e.owner, target) }
+
 func mapPublicError(err error) error {
 	if err == nil {
 		return nil
 	}
+	var operation *usecase.OperationError
+	if errors.As(err, &operation) && operation != nil {
+		owner := publicErrorFor(operation.Category)
+		if owner != nil {
+			// Project the underlying specialized error separately, retaining both
+			// the outer operation and the original cause for Is/As callers.
+			mapped := mapPublicError(operation.Cause)
+			if errors.Is(operation.Cause, llm.ErrTransport) {
+				mapped = errors.Join(ErrTransport, mapped)
+			}
+			if errors.Is(operation.Cause, llm.ErrMalformedResponse) {
+				mapped = errors.Join(ErrMalformedResponse, mapped)
+			}
+			// The projection already retains ordinary causes; adding the original
+			// again would duplicate its entire subtree at each enclosing operation.
+			return &publicOperationError{owner: owner, cause: mapped, message: fmt.Sprintf("%v: %v", owner, mapped)}
+		}
+	}
+	return mapUnownedPublicError(err)
+}
+
+func mapUnownedPublicError(err error) error {
 	var internalCapacityError *usecase.CapacityError
 	if errors.As(err, &internalCapacityError) && internalCapacityError != nil &&
 		strings.TrimSpace(internalCapacityError.BackendID) != "" {

errors_internal_test.go

@@ -80,3 +80,12 @@ func TestMapPublicErrorDoesNotTreatRequestEncodingAsTransport(t *testing.T) {
 		t.Fatalf("request encoding category = %v", err)
 	}
 }
+
+func TestMapPublicErrorRetainsOwnerWithSpecializedCapacity(t *testing.T) {
+	internal := &usecase.CapacityError{BackendID: "limited"}
+	err := mapPublicError(&usecase.OperationError{Category: usecase.ErrLLMGenerate, Cause: internal})
+	var capacity *CapacityError
+	if !errors.Is(err, ErrLLMGenerate) || !errors.As(err, &capacity) || capacity.BackendID != "limited" || !errors.Is(err, ErrCapacityExceeded) {
+		t.Fatalf("mapped owned capacity = %v", err)
+	}
+}

examples/go-library/observe/main.go

@@ -98,7 +98,7 @@ func run() (summary, error) {
 	engine, err := promptkit.NewEngine(promptkit.Config{
 		Sources:    promptkit.ConfigurationSources{Underlays: []configkit.Underlay{{Inputs: inputs}}},
 		HTTPClient: &http.Client{Transport: transport},
-	}, promptkit.WithSchemaFS(assets, "schemas"))
+	}, promptkit.WithBundledOpenRouter(false), promptkit.WithSchemaFS(assets, "schemas")) // Keep the example's configuration self-contained.
 	if err != nil {
 		return summary{}, err
 	}

examples/go-library/prepare/main.go

@@ -63,7 +63,7 @@ func run(ctx context.Context, exampleDir string, out io.Writer) error {
 			{Inputs: []configkit.Input{support, review}},
 			{Inputs: []configkit.Input{override}},
 		},
-	}})
+	}}, promptkit.WithBundledOpenRouter(false)) // Keep this example's inventory caller-owned.
 	if err != nil {
 		return err
 	}

examples/go-library/run/main.go

@@ -54,7 +54,7 @@ func run(ctx context.Context, exampleDir string, out io.Writer) error {
 			{ID: "offline-example", Endpoint: &endpoint, Model: &model},
 		})}}}},
 		Main: &configkit.Input{Source: configkit.File(filepath.Join(exampleDir, "prompt.yaml"))},
-	}}, promptkit.WithLLMClient(deterministicClient{}))
+	}}, promptkit.WithBundledOpenRouter(false), promptkit.WithLLMClient(deterministicClient{})) // Use only this example's offline configuration.
 	if err != nil {
 		return err
 	}

go.mod

@@ -4,12 +4,12 @@ go 1.27.0
 
 require (
 	github.com/santhosh-tekuri/jsonschema/v6 v6.0.2
-	go.maximumdirect.net/configkit v1.0.0
+	go.maximumdirect.net/configkit v1.1.0
 )
 
 require (
 	github.com/yuin/goldmark/v2 v2.1.6 // indirect
-	go.maximumdirect.net/releasekit v0.8.0 // indirect
+	go.maximumdirect.net/releasekit v0.9.0 // indirect
 	go.yaml.in/yaml/v4 v4.0.0-rc.6 // indirect
 	golang.org/x/mod v0.40.0 // indirect
 	golang.org/x/text v0.14.0 // indirect

go.sum

@@ -4,10 +4,10 @@ github.com/santhosh-tekuri/jsonschema/v6 v6.0.2 h1:KRzFb2m7YtdldCEkzs6KqmJw4nqEV
 github.com/santhosh-tekuri/jsonschema/v6 v6.0.2/go.mod h1:JXeL+ps8p7/KNMjDQk3TCwPpBy0wYklyWTfbkIzdIFU=
 github.com/yuin/goldmark/v2 v2.1.6 h1:igy0q9JcqovoFXFx/XjtU8sHVhcUHavPj2sA3EoKJUE=
 github.com/yuin/goldmark/v2 v2.1.6/go.mod h1:G6M4/qOFtfn01/o14BU1UR2Lo5N3S9Qo7xCuz/sHjGQ=
-go.maximumdirect.net/configkit v1.0.0 h1:cguQnxkaRk3ClQOZNzzhTdc4bfzbraGKv8CkoCp+HLc=
+go.maximumdirect.net/configkit v1.1.0 h1:UzXN2ZMnEkcL0O4YSLqD9qd9M1gb/NWCHQR/H8AaQzA=
-go.maximumdirect.net/configkit v1.0.0/go.mod h1:B6fJ5xBLBF1nuywqfLeEI4sLm29UkIcDLu8i6I6gGXE=
+go.maximumdirect.net/configkit v1.1.0/go.mod h1:s1zLJ9GGB/1Q4a+aOHMLISonJxWFgNWpA6SpPlOafeA=
-go.maximumdirect.net/releasekit v0.8.0 h1:hSaHPbUI7tAhnolfbu7UMj2fvmm9FGBY+jhkygdbxR0=
+go.maximumdirect.net/releasekit v0.9.0 h1:sK+Aoj6gS6ATU/1reocjwBekp4YETYENwkcX5ti6mrE=
-go.maximumdirect.net/releasekit v0.8.0/go.mod h1:QE4BLrAhVJTzi+/YTcVl21K/qZp9ojRLg5kuoy3Zb44=
+go.maximumdirect.net/releasekit v0.9.0/go.mod h1:QE4BLrAhVJTzi+/YTcVl21K/qZp9ojRLg5kuoy3Zb44=
 go.yaml.in/yaml/v4 v4.0.0-rc.6 h1:1h7H1ohdUh93/FyE4YaDa1Zh64K6VVbjF4K6WUxMtH4=
 go.yaml.in/yaml/v4 v4.0.0-rc.6/go.mod h1:aZqd9kCMsGL7AuUv/m/PvWLdg5sjJsZ4oHDEnfPPfY0=
 golang.org/x/mod v0.40.0 h1:hUv+3cXcdRHz08UmSiOob7sadHig73uo5bkXxQ/tvUs=

internal/artifact/reader_benchmark_test.go

@@ -3,8 +3,6 @@ package artifact
 import (
 	"bytes"
 	"context"
-	"crypto/sha256"
-	"fmt"
 	"mime"
 	"os"
 	"path/filepath"
@@ -153,9 +151,12 @@ func checkArtifactFileRead(b *testing.B, reader Reader, ref domain.ArtifactRef,
 	if !bytes.Equal(artifact.Body, want) || artifact.Size != int64(len(want)) {
 		b.Fatalf("artifact size=%d body length=%d, want %d", artifact.Size, len(artifact.Body), len(want))
 	}
-	wantHash := fmt.Sprintf("%x", sha256.Sum256(want))
+	inline, err := NewCompositeReader().Read(context.Background(), domain.ArtifactRef{Type: domain.ArtifactRefInline, Body: string(want)})
-	if artifact.Hash != wantHash {
+	if err != nil {
-		b.Fatalf("artifact hash=%q, want %q", artifact.Hash, wantHash)
+		b.Fatal(err)
+	}
+	if inline.Hash == "" || artifact.Hash != inline.Hash {
+		b.Fatalf("file and inline hashes differ: %q/%q", artifact.Hash, inline.Hash)
 	}
 }
 

internal/artifact/reader_test.go

@@ -3,9 +3,7 @@ package artifact
 import (
 	"bytes"
 	"context"
-	"crypto/sha256"
 	"errors"
-	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
@@ -284,9 +282,12 @@ func TestFileReaderUsesOpenedSizeOnlyAsACapacityHint(t *testing.T) {
 			if artifact.Name != filepath.Base(filePath) || artifact.URI != filePath || artifact.ContentType == "" {
 				t.Fatalf("unexpected artifact metadata: name=%q URI=%q content type=%q", artifact.Name, artifact.URI, artifact.ContentType)
 			}
-			wantHash := fmt.Sprintf("%x", sha256.Sum256(tc.body))
+			inline, err := NewCompositeReader().Read(context.Background(), domain.ArtifactRef{Type: domain.ArtifactRefInline, Body: string(tc.body)})
-			if artifact.Hash != wantHash {
+			if err != nil {
-				t.Fatalf("artifact hash=%q, want %q", artifact.Hash, wantHash)
+				t.Fatal(err)
+			}
+			if inline.Hash == "" || artifact.Hash != inline.Hash {
+				t.Fatalf("file and inline hashes differ: %q/%q", artifact.Hash, inline.Hash)
 			}
 		})
 	}

internal/backend/registry.go

@@ -27,17 +27,13 @@ type Registry struct {
 // NewEffectiveRegistry stores already-validated effective backend definitions
 // under their exact configuration keys. Configuration validation and
 // normalization precede this ownership boundary.
-func NewEffectiveRegistry(definitions map[string]domain.Backend) (*Registry, error) {
+func NewEffectiveRegistry(definitions map[string]domain.Backend) *Registry {
 	registry := &Registry{backends: make(map[string]domain.Backend, len(definitions))}
 	for id, definition := range definitions {
 		definition.ID = id
-		cloned, err := domain.CloneBackend(definition)
+		registry.backends[id] = domain.CloneBackend(definition)
-		if err != nil {
-			return nil, fmt.Errorf("backend %q: %w", id, err)
-		}
-		registry.backends[id] = cloned
 	}
-	return registry, nil
+	return registry
 }
 
 // GetBackend returns a defensive copy of the backend registered with id.
@@ -49,11 +45,7 @@ func (r *Registry) GetBackend(id string) (domain.Backend, error) {
 	if !ok {
 		return domain.Backend{}, fmt.Errorf("%w: %q", ErrBackendNotFound, id)
 	}
-	cloned, err := domain.CloneBackend(definition)
+	return domain.CloneBackend(definition), nil
-	if err != nil {
-		return domain.Backend{}, fmt.Errorf("copy backend %q: %w", id, err)
-	}
-	return cloned, nil
 }
 
 // CapacityPolicies returns a copy of the normalized policies for limited

internal/backend/registry_test.go

@@ -22,16 +22,13 @@ func TestEffectiveRegistryOwnsDefinitionsAndCapacityPolicies(t *testing.T) {
 			Kind: &authenticationKind, Endpoint: &authenticationEndpoint,
 		},
 	}
-	registry, err := backend.NewEffectiveRegistry(map[string]domain.Backend{
+	registry := backend.NewEffectiveRegistry(map[string]domain.Backend{
 		" local.v1 ": {
 			Endpoint: "https://backend.example/v1", ExtraParams: params,
-			ConcurrencyLimit: 2, QueueCapacity: 3, QueueCapacitySet: true,
+			ConcurrencyLimit: 2, QueueCapacity: 3,
 			SmokeTests: smokeTests,
 		},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 	params["nested"].(map[string]any)["enabled"] = false
 	defaultProfile = "mutated-profile"
 	reachabilityEndpoint = "https://mutated.example/ready"
@@ -79,10 +76,7 @@ func TestEffectiveRegistryOwnsDefinitionsAndCapacityPolicies(t *testing.T) {
 }
 
 func TestEffectiveRegistryMissingBackend(t *testing.T) {
-	registry, err := backend.NewEffectiveRegistry(nil)
+	registry := backend.NewEffectiveRegistry(nil)
-	if err != nil {
-		t.Fatal(err)
-	}
 	if _, err := registry.GetBackend("missing"); !errors.Is(err, backend.ErrBackendNotFound) {
 		t.Fatalf("missing backend error = %v", err)
 	}

internal/capacity/client.go

@@ -1,40 +0,0 @@
-package capacity
-
-import (
-	"context"
-
-	"go.maximumdirect.net/promptkit/internal/domain"
-	"go.maximumdirect.net/promptkit/internal/llm"
-)
-
-type client struct {
-	manager *Manager
-	next    llm.Client
-}
-
-// NewClient wraps next with configured active-generation limits. A nil manager
-// leaves next unchanged.
-func NewClient(manager *Manager, next llm.Client) llm.Client {
-	if manager == nil {
-		return next
-	}
-	return &client{
-		manager: manager,
-		next:    next,
-	}
-}
-
-func (c *client) Generate(
-	ctx context.Context,
-	req domain.GenerateRequest,
-) (*domain.GenerateResponse, error) {
-	if c.manager.getPool(req.Target.BackendID) == nil {
-		return c.next.Generate(ctx, req)
-	}
-	release, err := c.manager.Acquire(ctx, req.Target.BackendID)
-	if err != nil {
-		return nil, err
-	}
-	defer release()
-	return c.next.Generate(ctx, req)
-}

internal/capacity/client_test.go

@@ -3,7 +3,6 @@ package capacity
 import (
 	"context"
 	"errors"
-	"reflect"
 	"runtime"
 	"sync"
 	"sync/atomic"
@@ -24,6 +23,18 @@ type clientFunc func(
 	domain.GenerateRequest,
 ) (*domain.GenerateResponse, error)
 
+// newTestClient exercises one acquisition around a controlled call.
+func newTestClient(manager *Manager, next llm.Client) llm.Client {
+	return clientFunc(func(ctx context.Context, req domain.GenerateRequest) (*domain.GenerateResponse, error) {
+		release, err := manager.Acquire(ctx, req.Target.BackendID)
+		if err != nil {
+			return nil, err
+		}
+		defer release()
+		return next.Generate(ctx, req)
+	})
+}
+
 func (f clientFunc) Generate(
 	ctx context.Context,
 	req domain.GenerateRequest,
@@ -167,7 +178,7 @@ func TestClientLimitsPeakConcurrencyAndServesWaitersFIFO(t *testing.T) {
 		"second": secondRelease,
 		"third":  thirdRelease,
 	})
-	client := NewClient(manager, next)
+	client := newTestClient(manager, next)
 
 	first := generateAsync(client, context.Background(), "limited", "first")
 	if got := receiveStarted(t, next.started); got != "first" {
@@ -212,7 +223,7 @@ func TestClientPeakConcurrencyDoesNotExceedConfiguredLimit(t *testing.T) {
 		releases[string(rune('a'+i))] = gate
 	}
 	next := newBlockingClient(releases)
-	client := NewClient(manager, next)
+	client := newTestClient(manager, next)
 
 	results := make([]<-chan generateResult, 0, len(releases))
 	for id := range releases {
@@ -257,7 +268,7 @@ func TestClientRemovesCanceledWaiters(t *testing.T) {
 				"three":  make(chan struct{}),
 			}
 			next := newBlockingClient(releases)
-			client := NewClient(manager, next)
+			client := newTestClient(manager, next)
 
 			holder := generateAsync(client, context.Background(), "limited", "holder")
 			if got := receiveStarted(t, next.started); got != "holder" {
@@ -321,7 +332,7 @@ func TestClientGrantCancellationRaceDoesNotLeakPermit(t *testing.T) {
 			}
 			return &domain.GenerateResponse{Content: req.Prompt.SessionID}, nil
 		})
-		client := NewClient(manager, next)
+		client := newTestClient(manager, next)
 
 		holder := generateAsync(client, context.Background(), "limited", "holder")
 		waitForActiveCount(t, manager, "limited", 1)
@@ -394,7 +405,7 @@ func TestClientUsesIndependentPoolsAndUnlimitedFastPaths(t *testing.T) {
 		"alpha": alphaRelease,
 		"beta":  betaRelease,
 	})
-	client := NewClient(manager, next)
+	client := newTestClient(manager, next)
 
 	alpha := generateAsync(client, context.Background(), "alpha", "alpha")
 	beta := generateAsync(client, context.Background(), "beta", "beta")
@@ -423,63 +434,6 @@ func TestClientUsesIndependentPoolsAndUnlimitedFastPaths(t *testing.T) {
 			t.Fatalf("unlimited backend %q response=(%#v, %v)", backendID, response, err)
 		}
 	}
-	if got := NewClient(nil, next); got != next {
-		t.Fatal("nil manager did not return the wrapped client unchanged")
-	}
-}
-
-func TestClientPreservesRequestsResponsesAndErrors(t *testing.T) {
-	manager := newTestManager(t, map[string]domain.BackendCapacityPolicy{
-		"limited": {ConcurrencyLimit: 1},
-	})
-	request := domain.GenerateRequest{
-		Prompt: domain.RenderedPrompt{
-			SessionID: "session",
-			Messages: []domain.RenderedMessage{
-				{Role: "user", Content: "content"},
-			},
-		},
-		Target: domain.ExecutionTarget{
-			BackendID:   "limited",
-			Model:       "model",
-			ExtraParams: map[string]any{"key": "value"},
-		},
-	}
-	response := &domain.GenerateResponse{
-		Content: "output",
-		Usage:   domain.TokenUsage{TotalTokens: 7},
-	}
-	collaboratorErr := errors.New("collaborator failure")
-	tests := []struct {
-		name     string
-		response *domain.GenerateResponse
-		err      error
-	}{
-		{name: "successful response", response: response},
-		{name: "nil response"},
-		{name: "collaborator error", response: response, err: collaboratorErr},
-	}
-
-	for _, tc := range tests {
-		t.Run(tc.name, func(t *testing.T) {
-			var captured domain.GenerateRequest
-			next := clientFunc(func(
-				_ context.Context,
-				req domain.GenerateRequest,
-			) (*domain.GenerateResponse, error) {
-				captured = req
-				return tc.response, tc.err
-			})
-			gotResponse, gotErr := NewClient(manager, next).Generate(context.Background(), request)
-			if !reflect.DeepEqual(captured, request) {
-				t.Fatalf("request changed: %#v", captured)
-			}
-			if gotResponse != tc.response || gotErr != tc.err {
-				t.Fatalf("response=(%p, %v), want (%p, %v)",
-					gotResponse, gotErr, tc.response, tc.err)
-			}
-		})
-	}
 }
 
 func TestClientReleasesPermitDuringPanicUnwinding(t *testing.T) {
@@ -496,7 +450,7 @@ func TestClientReleasesPermitDuringPanicUnwinding(t *testing.T) {
 		}
 		return &domain.GenerateResponse{Content: "recovered"}, nil
 	})
-	client := NewClient(manager, next)
+	client := newTestClient(manager, next)
 	request := domain.GenerateRequest{
 		Target: domain.ExecutionTarget{BackendID: "limited"},
 	}

internal/configuration/bundled.go

@@ -0,0 +1,16 @@
+package configuration
+
+import (
+	"embed"
+
+	"go.maximumdirect.net/configkit"
+)
+
+//go:embed bundled/openrouter.yaml
+var bundledFiles embed.FS
+
+// BundledOpenRouterUnderlay returns the built-in OpenRouter configuration source.
+func BundledOpenRouterUnderlay() configkit.Underlay {
+	filesystem := configkit.NewFilesystem("Promptkit bundled OpenRouter", bundledFiles)
+	return configkit.Underlay{Inputs: []configkit.Input{{Source: filesystem.File("bundled/openrouter.yaml")}}}
+}

internal/configuration/bundled/openrouter.yaml

@@ -0,0 +1,60 @@
+backends:
+  - id: openrouter
+    endpoint: https://openrouter.ai/api/v1
+    api_key_env: OPENROUTER_API_KEY
+    smoke_tests:
+      default_profile: gpt-luna-latest
+      authentication:
+        kind: openrouter_key
+profiles:
+  - id: gpt-astra-latest
+    backend: openrouter
+    model: ~openai/gpt-astra-latest
+  - id: gpt-sol-latest
+    backend: openrouter
+    model: ~openai/gpt-sol-latest
+  - id: gpt-terra-latest
+    backend: openrouter
+    model: ~openai/gpt-terra-latest
+  - id: gpt-luna-latest
+    backend: openrouter
+    model: ~openai/gpt-luna-latest
+  - id: claude-fable-latest
+    backend: openrouter
+    model: ~anthropic/claude-fable-latest
+  - id: claude-opus-latest
+    backend: openrouter
+    model: ~anthropic/claude-opus-latest
+  - id: claude-sonnet-latest
+    backend: openrouter
+    model: ~anthropic/claude-sonnet-latest
+  - id: claude-haiku-latest
+    backend: openrouter
+    model: ~anthropic/claude-haiku-latest
+  - id: gemini-pro-latest
+    backend: openrouter
+    model: ~google/gemini-pro-latest
+  - id: gemini-flash-latest
+    backend: openrouter
+    model: ~google/gemini-flash-latest
+  - id: auto
+    backend: openrouter
+    model: openrouter/auto
+  - id: free
+    backend: openrouter
+    model: openrouter/free
+  - id: auto-low
+    extends: {id: auto}
+    extra_params: {plugins: [{id: auto-router, cost_tier: low}]}
+  - id: auto-medium
+    extends: {id: auto}
+    extra_params: {plugins: [{id: auto-router, cost_tier: medium}]}
+  - id: auto-high
+    extends: {id: auto}
+    extra_params: {plugins: [{id: auto-router, cost_tier: high}]}
+  - id: auto-xhigh
+    extends: {id: auto}
+    extra_params: {plugins: [{id: auto-router, cost_tier: xhigh}]}
+  - id: auto-max
+    extends: {id: auto}
+    extra_params: {plugins: [{id: auto-router, cost_tier: max}]}

internal/configuration/bundled_test.go

@@ -0,0 +1,54 @@
+package configuration
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"strings"
+	"testing"
+
+	"go.maximumdirect.net/configkit"
+	"go.maximumdirect.net/promptkit/internal/defaults"
+)
+
+func TestBundledOpenRouterUnderlay(t *testing.T) {
+	state, err := Load(configkit.Input{Source: configkit.NoSource()}, []configkit.Underlay{BundledOpenRouterUnderlay()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	backend, err := state.GetBackend("openrouter")
+	if err != nil || backend.Endpoint != "https://openrouter.ai/api/v1" || backend.APIKeyEnv != "OPENROUTER_API_KEY" || backend.SmokeTests == nil || backend.SmokeTests.DefaultProfile == nil || *backend.SmokeTests.DefaultProfile != "gpt-luna-latest" || backend.SmokeTests.Authentication == nil || backend.SmokeTests.Authentication.Kind == nil || *backend.SmokeTests.Authentication.Kind != "openrouter_key" {
+		t.Fatalf("backend = %+v, %v", backend, err)
+	}
+	if !reflect.DeepEqual(state.backendIDs, []string{"openrouter"}) || len(state.promptIDs) != 0 || len(state.collections) != 0 {
+		t.Fatalf("bundle inventories: backends=%v prompts=%v collections=%v", state.backendIDs, state.promptIDs, state.collections)
+	}
+	models := map[string]string{
+		"gpt-astra-latest": "~openai/gpt-astra-latest", "gpt-sol-latest": "~openai/gpt-sol-latest", "gpt-terra-latest": "~openai/gpt-terra-latest", "gpt-luna-latest": "~openai/gpt-luna-latest",
+		"claude-fable-latest": "~anthropic/claude-fable-latest", "claude-opus-latest": "~anthropic/claude-opus-latest", "claude-sonnet-latest": "~anthropic/claude-sonnet-latest", "claude-haiku-latest": "~anthropic/claude-haiku-latest",
+		"gemini-pro-latest": "~google/gemini-pro-latest", "gemini-flash-latest": "~google/gemini-flash-latest", "auto": "openrouter/auto", "free": "openrouter/free",
+	}
+	for _, tier := range []string{"low", "medium", "high", "xhigh", "max"} {
+		models["auto-"+tier] = "openrouter/auto"
+	}
+	if len(state.profileIDs) != len(models) {
+		t.Fatalf("profiles = %v", state.profileIDs)
+	}
+	for id, model := range models {
+		profile, err := state.GetProfile(context.Background(), id)
+		if err != nil {
+			t.Fatalf("profile %s = %+v, %v", id, profile, err)
+		}
+		want := defaults.ExecutionTargetDefault()
+		want.Model, want.BackendID, want.Endpoint, want.APIKeyEnv = model, "openrouter", "https://openrouter.ai/api/v1", "OPENROUTER_API_KEY"
+		if tier, ok := strings.CutPrefix(id, "auto-"); ok {
+			want.ExtraParams = map[string]any{"plugins": []any{map[string]any{"id": "auto-router", "cost_tier": tier}}}
+		}
+		if !reflect.DeepEqual(*profile.ResolvedTarget, want) {
+			t.Fatalf("profile %s target = %+v, want %+v", id, *profile.ResolvedTarget, want)
+		}
+	}
+	if !strings.Contains(fmt.Sprint(state.result.Sources()), "Promptkit bundled OpenRouter") {
+		t.Fatalf("source evidence = %+v", state.result.Sources())
+	}
+}

internal/configuration/interpretation_test.go

@@ -8,7 +8,7 @@ import (
 	"go.maximumdirect.net/configkit"
 )
 
-func TestTargetInterpretationPreservesComposedNestedValues(t *testing.T) {
+func TestTargetResolutionNormalizesNestedValues(t *testing.T) {
 	state, err := load(mapping("padded target", map[string]any{
 		"backends": []any{map[string]any{
 			"id": "local", "endpoint": " HTTPS://example.invalid/v1 ", "concurrency_limit": 1,
@@ -33,20 +33,32 @@ func TestTargetInterpretationPreservesComposedNestedValues(t *testing.T) {
 		t.Fatalf("interpreted profile = %+v, %v", profile, err)
 	}
 	composed := state.result.Config.Backends[0]
-	if *composed.Endpoint != " HTTPS://example.invalid/v1 " || composed.QueueCapacity != nil ||
+	if *composed.Endpoint != "https://example.invalid/v1" || composed.QueueCapacity == nil || *composed.QueueCapacity != 1024 ||
-		*composed.SmokeTests.Reachability.Endpoint != " https://example.invalid/health " ||
+		*composed.SmokeTests.Reachability.Endpoint != "https://example.invalid/health" ||
-		*composed.SmokeTests.Authentication.Kind != " NONE " || *composed.SmokeTests.Authentication.Endpoint != " https://example.invalid/key " ||
+		*composed.SmokeTests.Authentication.Kind != "none" || *composed.SmokeTests.Authentication.Endpoint != "https://example.invalid/key" ||
-		*state.result.Config.Profiles[0].ServiceTier != " standard " || *state.result.Config.Profiles[0].APIKeyEnv != " TOKEN " {
+		*state.result.Config.Profiles[0].ServiceTier != "standard" || *state.result.Config.Profiles[0].APIKeyEnv != "TOKEN" {
-		t.Fatalf("composed values were mutated: %+v", state.result.Config)
+		t.Fatalf("resolved values were not normalized: %+v", state.result.Config)
 	}
 	path := configkit.Keys("backends").Index(0).Key("smoke_tests").Key("authentication").Key("endpoint")
 	field, found := state.result.Metadata().Lookup(path)
-	if !found || len(field.Origin.Locations) == 0 || field.Origin.Operation == configkit.ChangeNormalization {
+	if !found || field.Origin.Operation != configkit.ChangeNormalization {
 		t.Fatalf("nested field origin changed: %+v", field)
 	}
+	for _, path := range []configkit.Path{
+		configkit.Keys("backends").Index(0).Key("endpoint"),
+		configkit.Keys("backends").Index(0).Key("smoke_tests").Key("reachability").Key("endpoint"),
+		configkit.Keys("backends").Index(0).Key("smoke_tests").Key("authentication").Key("kind"),
+		configkit.Keys("profiles").Index(0).Key("service_tier"),
+		configkit.Keys("profiles").Index(0).Key("api_key_env"),
+	} {
+		field, found := state.result.Metadata().Lookup(path)
+		if !found || field.Origin.Operation != configkit.ChangeNormalization {
+			t.Errorf("normalization at %v: %+v", path, field)
+		}
+	}
 }
 
-func TestPromptInterpretationPreservesComposedOutputAndRejectsDuplicateNames(t *testing.T) {
+func TestPromptResolutionNormalizesOutputAndRejectsDuplicateNames(t *testing.T) {
 	definition := map[string]any{
 		"id": "example", "inputs": []any{map[string]any{"name": " document "}},
 		"messages": []any{map[string]any{"role": "user", "content": "hello"}},
@@ -61,8 +73,8 @@ func TestPromptInterpretationPreservesComposedOutputAndRejectsDuplicateNames(t *
 		t.Fatalf("interpreted prompt = %+v, %+v, %v", selected, inspection, err)
 	}
 	composed := state.result.Config.Prompts[0]
-	if *composed.Output.SchemaPath != " schema.json " || composed.Inputs[0].Name != " document " {
+	if *composed.Output.SchemaPath != "schema.json" || composed.Inputs[0].Name != "document" {
-		t.Fatalf("composed prompt changed: %+v", composed)
+		t.Fatalf("prompt was not normalized: %+v", composed)
 	}
 	definition["inputs"] = []any{map[string]any{"name": " document "}, map[string]any{"name": "document"}}
 	_, err = load(mapping("duplicate inputs", map[string]any{"prompts": []any{definition}}), nil)
@@ -70,3 +82,71 @@ func TestPromptInterpretationPreservesComposedOutputAndRejectsDuplicateNames(t *
 		t.Fatalf("duplicate normalized names were not rejected: %v", err)
 	}
 }
+
+func TestPromptResolutionRecordsMessageFields(t *testing.T) {
+	loadPrompt := func(role, cacheType, ttl string) *loaded {
+		t.Helper()
+		state, err := load(mapping("prompt", map[string]any{"prompts": []any{map[string]any{
+			"id": "example", "inputs": []any{map[string]any{"name": " input ", "content_type": nil, "description": " text "}},
+			"messages": []any{map[string]any{"role": role, "content": "", "cache_control": map[string]any{"type": cacheType, "ttl": ttl}}},
+			"output":   map[string]any{"format": "text", "validation_mode": "basic"},
+		}}}), nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return state
+	}
+	padded := loadPrompt(" USER ", " ephemeral ", " 1h ")
+	canonical := loadPrompt("user", "ephemeral", "1h")
+	definition, inspection, err := padded.prompt("example")
+	if err != nil {
+		t.Fatal(err)
+	}
+	other, otherInspection, err := canonical.prompt("example")
+	if err != nil || inspection.PromptHash != otherInspection.PromptHash || definition.Templates[0].Role != other.Templates[0].Role || definition.Templates[0].Content != "" {
+		t.Fatalf("equivalent prompt mismatch: %+v %+v %v", definition, other, err)
+	}
+	base := configkit.Keys("prompts").Index(0)
+	for _, path := range []configkit.Path{base.Key("inputs").Index(0).Key("name"), base.Key("inputs").Index(0).Key("description"), base.Key("messages").Index(0).Key("role"), base.Key("messages").Index(0).Key("cache_control").Key("type"), base.Key("messages").Index(0).Key("cache_control").Key("ttl")} {
+		field, found := padded.result.Metadata().Lookup(path)
+		if !found || field.Origin.Operation != configkit.ChangeNormalization {
+			t.Errorf("normalization at %v: %+v", path, field)
+		}
+	}
+	if padded.promptMetadata["example"][0].contentType != fieldNull {
+		t.Fatal("null input metadata was not retained")
+	}
+}
+
+func TestResolutionRecordsTargetDependencies(t *testing.T) {
+	backend := func(id string) map[string]any {
+		return map[string]any{"id": id, "endpoint": " HTTPS://example.invalid/v1 ", "concurrency_limit": 2, "queue_capacity": nil}
+	}
+	state, err := load(mapping("targets", map[string]any{
+		"backends":    []any{backend("root")},
+		"collections": map[string]any{"scoped": map[string]any{"backends": []any{backend("local")}}},
+	}), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, base := range []configkit.Path{configkit.Keys("backends").Index(0), configkit.Keys("collections", "scoped", "backends").Index(0)} {
+		endpoint, ok := state.result.Explain(base.Key("endpoint"))
+		if !ok || !strings.Contains(endpoint.Effective.YAML, "https://example.invalid/v1") {
+			t.Fatalf("endpoint explanation: %+v", endpoint)
+		}
+		history := state.result.Metadata().History(base.Key("queue_capacity"))
+		found := false
+		for _, change := range history {
+			if change.Origin.Operation == configkit.ChangeDerivedDefault {
+				for _, dependency := range change.Dependencies {
+					if dependency.String() == base.Key("concurrency_limit").String() {
+						found = true
+					}
+				}
+			}
+		}
+		if !found {
+			t.Fatalf("missing queue dependency: %+v", history)
+		}
+	}
+}

internal/configuration/listing.go

@@ -2,36 +2,66 @@ package configuration
 
 import (
 	"context"
+	"sort"
+	"strings"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
 )
 
+// IdentityFilter selects all identities, one namespace, or unqualified IDs.
+type IdentityFilter struct {
+	All       bool
+	Namespace string
+}
+
+func selectIdentities[T any](ctx context.Context, entries []T, filter IdentityFilter, id func(T) string) ([]T, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if filter.All {
+		result := append([]T(nil), entries...)
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		return result, nil
+	}
+	if filter.Namespace != "" {
+		prefix := filter.Namespace + "/"
+		start := sort.Search(len(entries), func(i int) bool { return id(entries[i]) >= prefix })
+		end := start + sort.Search(len(entries)-start, func(i int) bool { return !strings.HasPrefix(id(entries[start+i]), prefix) })
+		result := append([]T(nil), entries[start:end]...)
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		return result, nil
+	}
+	var result []T
+	for _, entry := range entries {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		if !strings.Contains(id(entry), "/") {
+			result = append(result, entry)
+		}
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	return result, nil
+}
+
 // CollectionIdentity is the captured metadata for one final collection entry.
 type CollectionIdentity struct {
 	Namespace      string
 	ReleaseVersion *string
 }
 
-func (state *loaded) ListProfiles(ctx context.Context) ([]string, error) {
+func (state *loaded) ListProfiles(ctx context.Context, filter IdentityFilter) ([]string, error) {
-	if err := ctx.Err(); err != nil {
+	return selectIdentities(ctx, state.profileIDs, filter, func(id string) string { return id })
-		return nil, err
-	}
-	profiles := append([]string(nil), state.profileIDs...)
-	if err := ctx.Err(); err != nil {
-		return nil, err
-	}
-	return profiles, nil
 }
 
-func (state *loaded) ListBackends(ctx context.Context) ([]string, error) {
+func (state *loaded) ListBackends(ctx context.Context, filter IdentityFilter) ([]string, error) {
-	if err := ctx.Err(); err != nil {
+	return selectIdentities(ctx, state.backendIDs, filter, func(id string) string { return id })
-		return nil, err
-	}
-	backends := append([]string(nil), state.backendIDs...)
-	if err := ctx.Err(); err != nil {
-		return nil, err
-	}
-	return backends, nil
 }
 
 func (state *loaded) ListNamespaces(ctx context.Context, kinds []string) ([]string, error) {
@@ -72,13 +102,6 @@ func (state *loaded) ListCollections(ctx context.Context) ([]CollectionIdentity,
 	return collections, nil
 }
 
-func (state *loaded) ListPrompts(ctx context.Context) ([]domain.PromptIdentity, error) {
+func (state *loaded) ListPrompts(ctx context.Context, filter IdentityFilter) ([]domain.PromptIdentity, error) {
-	if err := ctx.Err(); err != nil {
+	return selectIdentities(ctx, state.promptIDs, filter, func(entry domain.PromptIdentity) string { return entry.ID })
-		return nil, err
-	}
-	prompts := append([]domain.PromptIdentity(nil), state.promptIDs...)
-	if err := ctx.Err(); err != nil {
-		return nil, err
-	}
-	return prompts, nil
 }

internal/configuration/listing_test.go

@@ -23,7 +23,7 @@ func TestLoadedListsSortedEffectiveIdentities(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	backends, err := state.ListBackends(context.Background())
+	backends, err := state.ListBackends(context.Background(), IdentityFilter{All: true})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -32,7 +32,7 @@ func TestLoadedListsSortedEffectiveIdentities(t *testing.T) {
 		t.Fatalf("backend IDs = %#v, want %#v", backends, wantBackends)
 	}
 
-	profiles, err := state.ListProfiles(context.Background())
+	profiles, err := state.ListProfiles(context.Background(), IdentityFilter{All: true})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -41,7 +41,7 @@ func TestLoadedListsSortedEffectiveIdentities(t *testing.T) {
 		t.Fatalf("profile IDs = %#v, want %#v", profiles, wantProfiles)
 	}
 
-	prompts, err := state.ListPrompts(context.Background())
+	prompts, err := state.ListPrompts(context.Background(), IdentityFilter{All: true})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -65,36 +65,36 @@ func TestLoadedListsAreIndependent(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	profiles, err := state.ListProfiles(context.Background())
+	profiles, err := state.ListProfiles(context.Background(), IdentityFilter{All: true})
 	if err != nil {
 		t.Fatal(err)
 	}
 	profiles = append(profiles, "caller profile")
 	profiles[0] = "changed profile"
-	backends, err := state.ListBackends(context.Background())
+	backends, err := state.ListBackends(context.Background(), IdentityFilter{All: true})
 	if err != nil {
 		t.Fatal(err)
 	}
 	backends[0] = "changed backend"
 
-	prompts, err := state.ListPrompts(context.Background())
+	prompts, err := state.ListPrompts(context.Background(), IdentityFilter{All: true})
 	if err != nil {
 		t.Fatal(err)
 	}
 	prompts[0].ID = "changed prompt"
 
-	profiles, err = state.ListProfiles(context.Background())
+	profiles, err = state.ListProfiles(context.Background(), IdentityFilter{All: true})
 	if err != nil {
 		t.Fatal(err)
 	}
 	if !reflect.DeepEqual(profiles, []string{"profile"}) {
 		t.Fatalf("caller mutation changed profile inventory: %#v", profiles)
 	}
-	backends, err = state.ListBackends(context.Background())
+	backends, err = state.ListBackends(context.Background(), IdentityFilter{All: true})
 	if err != nil || !reflect.DeepEqual(backends, []string{"backend"}) {
 		t.Fatalf("caller mutation changed backend inventory: %#v, %v", backends, err)
 	}
-	prompts, err = state.ListPrompts(context.Background())
+	prompts, err = state.ListPrompts(context.Background(), IdentityFilter{All: true})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -104,20 +104,66 @@ func TestLoadedListsAreIndependent(t *testing.T) {
 	}
 }
 
+func TestLoadedListsSelectNamespaces(t *testing.T) {
+	ids := []string{"a", "a-b/one", "a/one", "a/two", "b", "z/one"}
+	state := &loaded{profileIDs: append([]string(nil), ids...), backendIDs: append([]string(nil), ids...)}
+	for _, id := range ids {
+		state.promptIDs = append(state.promptIDs, domain.PromptIdentity{ID: id})
+	}
+	cases := []struct {
+		name   string
+		filter IdentityFilter
+		want   []string
+	}{
+		{"all", IdentityFilter{All: true}, ids},
+		{"unqualified", IdentityFilter{}, []string{"a", "b"}},
+		{"namespace", IdentityFilter{Namespace: "a"}, []string{"a/one", "a/two"}},
+		{"prefix sharing", IdentityFilter{Namespace: "a-b"}, []string{"a-b/one"}},
+		{"missing", IdentityFilter{Namespace: "absent"}, nil},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			profiles, err := state.ListProfiles(context.Background(), tc.filter)
+			if err != nil || !reflect.DeepEqual(profiles, tc.want) {
+				t.Fatalf("profiles = %v, %v; want %v", profiles, err, tc.want)
+			}
+			backends, err := state.ListBackends(context.Background(), tc.filter)
+			if err != nil || !reflect.DeepEqual(backends, tc.want) {
+				t.Fatalf("backends = %v, %v; want %v", backends, err, tc.want)
+			}
+			prompts, err := state.ListPrompts(context.Background(), tc.filter)
+			if err != nil || len(prompts) != len(tc.want) {
+				t.Fatalf("prompts = %v, %v; want %v", prompts, err, tc.want)
+			}
+			for i := range prompts {
+				if prompts[i].ID != tc.want[i] {
+					t.Fatalf("prompt ID = %q; want %q", prompts[i].ID, tc.want[i])
+				}
+			}
+			if len(profiles) > 0 {
+				profiles[0], backends[0], prompts[0].ID = "changed", "changed", "changed"
+			}
+		})
+	}
+	if !reflect.DeepEqual(state.profileIDs, ids) || !reflect.DeepEqual(state.backendIDs, ids) || state.promptIDs[0].ID != ids[0] {
+		t.Fatal("caller mutation changed captured identities")
+	}
+}
+
 func TestLoadedListsEmptyInventory(t *testing.T) {
 	state, err := Load(configkit.Input{Source: configkit.NoSource()}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
-	profiles, err := state.ListProfiles(context.Background())
+	profiles, err := state.ListProfiles(context.Background(), IdentityFilter{All: true})
 	if err != nil || len(profiles) != 0 {
 		t.Fatalf("empty profile listing = %#v, %v", profiles, err)
 	}
-	backends, err := state.ListBackends(context.Background())
+	backends, err := state.ListBackends(context.Background(), IdentityFilter{All: true})
 	if err != nil || len(backends) != 0 {
 		t.Fatalf("empty backend listing = %#v, %v", backends, err)
 	}
-	prompts, err := state.ListPrompts(context.Background())
+	prompts, err := state.ListPrompts(context.Background(), IdentityFilter{All: true})
 	if err != nil || len(prompts) != 0 {
 		t.Fatalf("empty prompt listing = %#v, %v", prompts, err)
 	}
@@ -134,17 +180,19 @@ func TestLoadedListsHonorCanceledContext(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
 
-	profiles, err := state.ListProfiles(ctx)
+	for _, filter := range []IdentityFilter{{All: true}, {}, {Namespace: "example"}} {
-	if !errors.Is(err, context.Canceled) || len(profiles) != 0 {
+		profiles, err := state.ListProfiles(ctx, filter)
-		t.Fatalf("canceled profile listing = %#v, %v", profiles, err)
+		if !errors.Is(err, context.Canceled) || len(profiles) != 0 {
-	}
+			t.Fatalf("canceled profile listing = %#v, %v", profiles, err)
-	backends, err := state.ListBackends(ctx)
+		}
-	if !errors.Is(err, context.Canceled) || len(backends) != 0 {
+		backends, err := state.ListBackends(ctx, filter)
-		t.Fatalf("canceled backend listing = %#v, %v", backends, err)
+		if !errors.Is(err, context.Canceled) || len(backends) != 0 {
-	}
+			t.Fatalf("canceled backend listing = %#v, %v", backends, err)
-	prompts, err := state.ListPrompts(ctx)
+		}
-	if !errors.Is(err, context.Canceled) || len(prompts) != 0 {
+		prompts, err := state.ListPrompts(ctx, filter)
-		t.Fatalf("canceled prompt listing = %#v, %v", prompts, err)
+		if !errors.Is(err, context.Canceled) || len(prompts) != 0 {
+			t.Fatalf("canceled prompt listing = %#v, %v", prompts, err)
+		}
 	}
 }
 

internal/configuration/load.go

@@ -4,7 +4,6 @@ package configuration
 
 import (
 	"fmt"
-	"net/http"
 	"regexp"
 	"sort"
 	"strings"
@@ -120,8 +119,6 @@ const (
 
 type loaded struct {
 	result          *configkit.Result[document]
-	interpreted     document
-	backends        map[string]map[string]fieldState
 	profiles        map[string]map[string]fieldState
 	promptMetadata  map[string][]promptInputPresence
 	prompts         map[string]*promptEntry
@@ -214,7 +211,6 @@ func indexedProfiles(config *document) map[string]profileConfig {
 
 var envName = regexp.MustCompile(`^[A-Za-z_][A-Za-z0-9_]*$`)
 
-var backendFields = []string{"endpoint", "api_key_env", "concurrency_limit", "queue_capacity", "extra_params", "smoke_tests"}
 var profileFields = []string{"backend", "endpoint", "model", "temperature", "top_p", "max_tokens", "timeout_seconds", "service_tier", "reasoning_effort", "api_key_env", "api_key_required", "extra_params"}
 
 // Load captures one immutable effective configuration for internal consumers.
@@ -239,15 +235,18 @@ func configurationDefinition(state *loaded) configkit.Definition[document] {
 		Sensitive: secretProviderPath,
 		Resolve: func(config *document, resolution *configkit.Resolution) error {
 			for _, resources := range resourceSets(config) {
-				captureFields(resources.backends, func(v backendConfig) string { return v.ID }, resources.bases.backends, resources.namespace, backendFields, resolution, state.backends)
 				captureFields(resources.profiles, func(v profileConfig) string { return v.ID }, resources.bases.profiles, resources.namespace, profileFields, resolution, state.profiles)
 				capturePromptMetadata(resources.prompts, resources.bases.prompts, resources.namespace, resolution, state.promptMetadata)
 			}
+			for _, resources := range resourceSets(config) {
+				resolveBackends(resources.backends, resources.bases.backends, resolution)
+				resolveProfiles(resources.profiles, resources.bases.profiles, resolution)
+				resolvePrompts(resources.prompts, resources.bases.prompts, resolution)
+			}
 			return nil
 		},
 		Validate: func(config *document, validation *configkit.Validation) {
-			state.interpreted = interpretConfiguration(config, validation)
+			validateEffective(config, validation)
-			validateEffective(&state.interpreted, validation)
 		},
 	}
 }
@@ -255,7 +254,6 @@ func configurationDefinition(state *loaded) configkit.Definition[document] {
 // load performs one ConfigKit lifecycle over the selected source tiers.
 func load(main configkit.Input, underlays []configkit.Underlay) (*loaded, error) {
 	state := &loaded{
-		backends:       make(map[string]map[string]fieldState),
 		profiles:       make(map[string]map[string]fieldState),
 		promptMetadata: make(map[string][]promptInputPresence),
 	}
@@ -274,7 +272,7 @@ func load(main configkit.Input, underlays []configkit.Underlay) (*loaded, error)
 	if err := state.buildExecutionProfiles(); err != nil {
 		return nil, fmt.Errorf("load configuration: %w", err)
 	}
-	state.backendIDs = sortedKeys(indexedBackends(&state.interpreted))
+	state.backendIDs = sortedKeys(indexedBackends(&state.result.Config))
 	state.profileIDs = sortedKeys(state.indexedProfiles)
 	for _, id := range sortedKeys(state.prompts) {
 		state.promptIDs = append(state.promptIDs, domain.PromptIdentity{ID: id})
@@ -372,6 +370,29 @@ func captureFields[T any](entries []T, identity func(T) string, basePath configk
 	}
 }
 
+// eligibleResourceList leaves invalid identities to the existing validation
+// boundaries, without mutating a list that cannot be recorded by identity.
+func eligibleResourceList[T any](entries []T, identity func(T) string) bool {
+	seen := make(map[string]struct{}, len(entries))
+	for _, entry := range entries {
+		id := identity(entry)
+		if !domain.IsValidLocalResourceKey(id) {
+			return false
+		}
+		if _, exists := seen[id]; exists {
+			return false
+		}
+		seen[id] = struct{}{}
+	}
+	return true
+}
+
+func recordStringNormalization(value **string, path configkit.Path, resolution *configkit.Resolution, normalized string) {
+	if *value != nil && **value != normalized {
+		configkit.Normalize(resolution, path, value, &normalized, "Normalize configured value")
+	}
+}
+
 func sortedKeys[T any](entries map[string]T) []string {
 	keys := make([]string, 0, len(entries))
 	for key := range entries {
@@ -381,113 +402,6 @@ func sortedKeys[T any](entries map[string]T) []string {
 	return keys
 }
 
-func interpretConfiguration(config *document, validation *configkit.Validation) document {
-	interpreted := *config
-	interpreted.Backends = interpretBackends(config.Backends, configkit.Keys("backends"), validation)
-	interpreted.Profiles = interpretProfiles(config.Profiles, configkit.Keys("profiles"), validation)
-	interpreted.Prompts = interpretPrompts(config.Prompts)
-	if config.Collections != nil {
-		interpreted.Collections = make(map[string]collectionConfig, len(config.Collections))
-		for namespace, original := range config.Collections {
-			collection := original
-			base := configkit.Keys("collections", namespace)
-			collection.Backends = interpretBackends(original.Backends, base.Key("backends"), validation)
-			collection.Profiles = interpretProfiles(original.Profiles, base.Key("profiles"), validation)
-			collection.Prompts = interpretPrompts(original.Prompts)
-			interpreted.Collections[namespace] = collection
-		}
-	}
-	return interpreted
-}
-
-func interpretBackends(source []backendConfig, basePath configkit.Path, validation *configkit.Validation) []backendConfig {
-	if source == nil {
-		return nil
-	}
-	backends := append([]backendConfig{}, source...)
-	for index := range backends {
-		backend := &backends[index]
-		base := basePath.Index(index)
-		if backend.Endpoint != nil {
-			endpoint, err := domain.NormalizeOpenAICompatibleBaseEndpoint(*backend.Endpoint)
-			if err != nil {
-				validation.Error(base.Key("endpoint"), err.Error())
-			} else {
-				backend.Endpoint = &endpoint
-			}
-		}
-		if backend.APIKeyEnv != nil {
-			value := strings.TrimSpace(*backend.APIKeyEnv)
-			backend.APIKeyEnv = &value
-		}
-		if backend.SmokeTests != nil {
-			smokeTests := *backend.SmokeTests
-			backend.SmokeTests = &smokeTests
-			smokePath := base.Key("smoke_tests")
-			if smokeTests.Reachability != nil {
-				reachability := *smokeTests.Reachability
-				smokeTests.Reachability = &reachability
-				normalizeDiagnosticEndpoint(&reachability.Endpoint, smokePath.Key("reachability").Key("endpoint"), validation)
-			}
-			if smokeTests.Authentication != nil {
-				authentication := *smokeTests.Authentication
-				smokeTests.Authentication = &authentication
-				if authentication.Kind != nil {
-					kind := strings.ToLower(strings.TrimSpace(*authentication.Kind))
-					authentication.Kind = &kind
-				}
-				normalizeDiagnosticEndpoint(&authentication.Endpoint, smokePath.Key("authentication").Key("endpoint"), validation)
-			}
-		}
-		if backend.ConcurrencyLimit != nil && *backend.ConcurrencyLimit > 0 && backend.QueueCapacity == nil {
-			capacity := 1024
-			backend.QueueCapacity = &capacity
-		}
-	}
-	return backends
-}
-
-func normalizeDiagnosticEndpoint(value **string, path configkit.Path, validation *configkit.Validation) {
-	if value == nil || *value == nil {
-		return
-	}
-	normalized := strings.TrimSpace(**value)
-	request, err := http.NewRequest(http.MethodGet, normalized, nil)
-	if normalized == "" || err != nil || request.URL == nil ||
-		(strings.ToLower(request.URL.Scheme) != "http" && strings.ToLower(request.URL.Scheme) != "https") ||
-		request.URL.Hostname() == "" {
-		validation.Error(path, "diagnostic endpoint must be an absolute HTTP(S) URL with a host")
-		return
-	}
-	*value = &normalized
-}
-
-func interpretProfiles(source []profileConfig, basePath configkit.Path, validation *configkit.Validation) []profileConfig {
-	if source == nil {
-		return nil
-	}
-	profiles := append([]profileConfig{}, source...)
-	for index := range profiles {
-		profile := &profiles[index]
-		base := basePath.Index(index)
-		if profile.Endpoint != nil && *profile.Endpoint != "" {
-			endpoint, err := domain.NormalizeOpenAICompatibleBaseEndpoint(*profile.Endpoint)
-			if err != nil {
-				validation.Error(base.Key("endpoint"), err.Error())
-			} else {
-				profile.Endpoint = &endpoint
-			}
-		}
-		for _, value := range []**string{&profile.ServiceTier, &profile.ReasoningEffort, &profile.APIKeyEnv} {
-			if *value != nil {
-				normalized := strings.TrimSpace(**value)
-				*value = &normalized
-			}
-		}
-	}
-	return profiles
-}
-
 func validateEffective(config *document, validation *configkit.Validation) {
 	sets := resourceSets(config)
 	backendIDs := make(map[string]struct{})
@@ -501,95 +415,110 @@ func validateEffective(config *document, validation *configkit.Validation) {
 	}
 	for _, resources := range sets {
 		for index, backend := range resources.backends {
-			base := resources.bases.backends.Index(index)
+			validateBackendRecord(backend, resources.bases.backends.Index(index), validation)
-			if !domain.IsValidLocalResourceKey(backend.ID) {
-				validation.Error(base.Key("id"), "backend ID must be a nonblank local key without a slash")
-			}
-			if backend.Endpoint == nil || *backend.Endpoint == "" {
-				validation.Error(base.Key("endpoint"), "endpoint is required")
-			}
-			if backend.APIKeyEnv != nil && *backend.APIKeyEnv != "" && !envName.MatchString(*backend.APIKeyEnv) {
-				validation.Error(base.Key("api_key_env"), "environment variable name is invalid")
-			}
-			if backend.ConcurrencyLimit != nil && *backend.ConcurrencyLimit < 0 {
-				validation.Error(base.Key("concurrency_limit"), "concurrency limit must not be negative")
-			}
-			if backend.QueueCapacity != nil {
-				if *backend.QueueCapacity < 0 {
-					validation.Error(base.Key("queue_capacity"), "queue capacity must not be negative")
-				}
-				if backend.ConcurrencyLimit == nil || *backend.ConcurrencyLimit <= 0 {
-					validation.Error(base.Key("queue_capacity"), "queue capacity requires a positive concurrency limit")
-				} else if *backend.QueueCapacity > int(^uint(0)>>1)-*backend.ConcurrencyLimit {
-					validation.Error(base.Key("queue_capacity"), "total capacity overflows int")
-				}
-			}
-			validateExtraParams(backend.ExtraParams, base.Key("extra_params"), true, validation)
-			if smokeTests := backend.SmokeTests; smokeTests != nil {
-				smokePath := base.Key("smoke_tests")
-				if smokeTests.DefaultProfile != nil {
-					if strings.TrimSpace(*smokeTests.DefaultProfile) == "" {
-						validation.Error(smokePath.Key("default_profile"), "default profile must not be blank")
-					} else if !domain.IsValidResourceID(*smokeTests.DefaultProfile) {
-						validation.Error(smokePath.Key("default_profile"), "default profile reference is malformed")
-					}
-				}
-				if authentication := smokeTests.Authentication; authentication != nil {
-					kindPath := smokePath.Key("authentication").Key("kind")
-					if authentication.Kind == nil {
-						validation.Error(kindPath, "authentication kind is required")
-					} else if *authentication.Kind != "none" && *authentication.Kind != "openrouter_key" {
-						validation.Error(kindPath, "authentication kind must be none or openrouter_key")
-					}
-				}
-			}
 		}
 		for index, profile := range resources.profiles {
-			base := resources.bases.profiles.Index(index)
+			validateProfileRecord(profile, resources.bases.profiles.Index(index), backendIDs, validation)
-			if !domain.IsValidLocalResourceKey(profile.ID) {
-				validation.Error(base.Key("id"), "profile ID must be a nonblank local key without a slash")
-			}
-			if profile.Backend != nil && *profile.Backend != "" {
-				if !domain.IsValidResourceID(*profile.Backend) {
-					validation.Error(base.Key("backend"), "backend reference is malformed")
-				} else if _, exists := backendIDs[*profile.Backend]; !exists {
-					validation.Error(base.Key("backend"), "backend is not defined")
-				}
-			}
-			if profile.Model != nil && *profile.Model != "" && strings.TrimSpace(*profile.Model) == "" {
-				validation.Error(base.Key("model"), "model must not be blank")
-			}
-			if profile.Temperature != nil {
-				if err := domain.ValidateExecutionTargetSettings(domain.ExecutionTarget{Temperature: *profile.Temperature}); err != nil {
-					validation.Error(base.Key("temperature"), err.Error())
-				}
-			}
-			if profile.TopP != nil {
-				if err := domain.ValidateExecutionTargetSettings(domain.ExecutionTarget{TopP: *profile.TopP}); err != nil {
-					validation.Error(base.Key("top_p"), err.Error())
-				}
-			}
-			if profile.MaxTokens != nil {
-				if err := domain.ValidateExecutionTargetSettings(domain.ExecutionTarget{MaxTokens: *profile.MaxTokens}); err != nil {
-					validation.Error(base.Key("max_tokens"), err.Error())
-				}
-			}
-			if profile.TimeoutSeconds != nil {
-				if err := domain.ValidateExecutionTargetSettings(domain.ExecutionTarget{TimeoutSeconds: *profile.TimeoutSeconds}); err != nil {
-					validation.Error(base.Key("timeout_seconds"), err.Error())
-				}
-			}
-			validateExtraParams(profile.ExtraParams, base.Key("extra_params"), false, validation)
 		}
 		for index, prompt := range resources.prompts {
-			base := resources.bases.prompts.Index(index)
+			validatePromptRecord(prompt, resources.bases.prompts.Index(index), validation)
-			if !domain.IsValidLocalResourceKey(prompt.ID) {
+		}
-				validation.Error(base.Key("id"), "prompt ID must be a nonblank local key without a slash")
+	}
-			}
+}
-			if prompt.DefaultProfile != nil && *prompt.DefaultProfile != "" && !domain.IsValidResourceID(*prompt.DefaultProfile) {
+
-				validation.Error(base.Key("default_profile"), "default profile reference is malformed")
+func validateBackendRecord(backend backendConfig, base configkit.Path, validation *configkit.Validation) {
+	validateBackendEndpoints(backend, base, validation)
+	if !domain.IsValidLocalResourceKey(backend.ID) {
+		validation.Error(base.Key("id"), "backend ID must be a nonblank local key without a slash")
+	}
+	if backend.Endpoint == nil || *backend.Endpoint == "" {
+		validation.Error(base.Key("endpoint"), "endpoint is required")
+	}
+	if backend.APIKeyEnv != nil && *backend.APIKeyEnv != "" && !envName.MatchString(*backend.APIKeyEnv) {
+		validation.Error(base.Key("api_key_env"), "environment variable name is invalid")
+	}
+	if backend.ConcurrencyLimit != nil && *backend.ConcurrencyLimit < 0 {
+		validation.Error(base.Key("concurrency_limit"), "concurrency limit must not be negative")
+	}
+	if backend.QueueCapacity != nil {
+		if *backend.QueueCapacity < 0 {
+			validation.Error(base.Key("queue_capacity"), "queue capacity must not be negative")
+		}
+		if backend.ConcurrencyLimit == nil || *backend.ConcurrencyLimit <= 0 {
+			validation.Error(base.Key("queue_capacity"), "queue capacity requires a positive concurrency limit")
+		} else if *backend.QueueCapacity > int(^uint(0)>>1)-*backend.ConcurrencyLimit {
+			validation.Error(base.Key("queue_capacity"), "total capacity overflows int")
+		}
+	}
+	validateExtraParams(backend.ExtraParams, base.Key("extra_params"), true, validation)
+	if smokeTests := backend.SmokeTests; smokeTests != nil {
+		smokePath := base.Key("smoke_tests")
+		if smokeTests.DefaultProfile != nil {
+			if strings.TrimSpace(*smokeTests.DefaultProfile) == "" {
+				validation.Error(smokePath.Key("default_profile"), "default profile must not be blank")
+			} else if !domain.IsValidResourceID(*smokeTests.DefaultProfile) {
+				validation.Error(smokePath.Key("default_profile"), "default profile reference is malformed")
 			}
 		}
+		if authentication := smokeTests.Authentication; authentication != nil {
+			kindPath := smokePath.Key("authentication").Key("kind")
+			if authentication.Kind == nil {
+				validation.Error(kindPath, "authentication kind is required")
+			} else if *authentication.Kind != "none" && *authentication.Kind != "openrouter_key" {
+				validation.Error(kindPath, "authentication kind must be none or openrouter_key")
+			}
+		}
+	}
+}
+
+func validateProfileRecord(profile profileConfig, base configkit.Path, backendIDs map[string]struct{}, validation *configkit.Validation) {
+	if profile.Endpoint != nil && *profile.Endpoint != "" {
+		if _, err := domain.NormalizeOpenAICompatibleBaseEndpoint(*profile.Endpoint); err != nil {
+			validation.Error(base.Key("endpoint"), err.Error())
+		}
+	}
+	if !domain.IsValidLocalResourceKey(profile.ID) {
+		validation.Error(base.Key("id"), "profile ID must be a nonblank local key without a slash")
+	}
+	if profile.Backend != nil && *profile.Backend != "" {
+		if !domain.IsValidResourceID(*profile.Backend) {
+			validation.Error(base.Key("backend"), "backend reference is malformed")
+		} else if _, exists := backendIDs[*profile.Backend]; !exists {
+			validation.Error(base.Key("backend"), "backend is not defined")
+		}
+	}
+	if profile.Model != nil && *profile.Model != "" && strings.TrimSpace(*profile.Model) == "" {
+		validation.Error(base.Key("model"), "model must not be blank")
+	}
+	if profile.Temperature != nil {
+		if err := domain.ValidateExecutionTargetSettings(domain.ExecutionTarget{Temperature: *profile.Temperature}); err != nil {
+			validation.Error(base.Key("temperature"), err.Error())
+		}
+	}
+	if profile.TopP != nil {
+		if err := domain.ValidateExecutionTargetSettings(domain.ExecutionTarget{TopP: *profile.TopP}); err != nil {
+			validation.Error(base.Key("top_p"), err.Error())
+		}
+	}
+	if profile.MaxTokens != nil {
+		if err := domain.ValidateExecutionTargetSettings(domain.ExecutionTarget{MaxTokens: *profile.MaxTokens}); err != nil {
+			validation.Error(base.Key("max_tokens"), err.Error())
+		}
+	}
+	if profile.TimeoutSeconds != nil {
+		if err := domain.ValidateExecutionTargetSettings(domain.ExecutionTarget{TimeoutSeconds: *profile.TimeoutSeconds}); err != nil {
+			validation.Error(base.Key("timeout_seconds"), err.Error())
+		}
+	}
+	validateExtraParams(profile.ExtraParams, base.Key("extra_params"), false, validation)
+}
+
+func validatePromptRecord(prompt promptConfig, base configkit.Path, validation *configkit.Validation) {
+	if !domain.IsValidLocalResourceKey(prompt.ID) {
+		validation.Error(base.Key("id"), "prompt ID must be a nonblank local key without a slash")
+	}
+	if prompt.DefaultProfile != nil && *prompt.DefaultProfile != "" && !domain.IsValidResourceID(*prompt.DefaultProfile) {
+		validation.Error(base.Key("default_profile"), "default profile reference is malformed")
 	}
 }
 

internal/configuration/load_test.go

@@ -153,6 +153,50 @@ func TestIdentifiedResourcesRejectDuplicateStrictPeers(t *testing.T) {
 	}
 }
 
+func TestInvalidIdentitiesWithNormalizableFieldsAreRejected(t *testing.T) {
+	for _, kind := range []string{"backends", "profiles", "prompts"} {
+		for _, id := range []string{" ", "bad/id"} {
+			t.Run(kind+"/"+id, func(t *testing.T) {
+				record := map[string]any{"id": id}
+				switch kind {
+				case "backends":
+					record["endpoint"] = " HTTPS://example.invalid/v1 "
+					record["concurrency_limit"] = 1
+				case "profiles":
+					record["service_tier"] = " standard "
+				case "prompts":
+					record["description"] = " padded "
+				}
+				_, err := load(mapping("invalid", map[string]any{kind: []any{record}}), nil)
+				if err == nil || strings.Contains(strings.ToLower(err.Error()), "unrecorded") {
+					t.Fatalf("invalid identity error = %v", err)
+				}
+			})
+		}
+	}
+}
+
+func TestDuplicateIdentitiesWithNormalizableFieldsAreRejected(t *testing.T) {
+	for _, kind := range []string{"backends", "profiles", "prompts"} {
+		t.Run(kind, func(t *testing.T) {
+			record := map[string]any{"id": "same"}
+			switch kind {
+			case "backends":
+				record["endpoint"] = " HTTPS://example.invalid/v1 "
+				record["concurrency_limit"] = 1
+			case "profiles":
+				record["service_tier"] = " standard "
+			case "prompts":
+				record["description"] = " padded "
+			}
+			_, err := load(mapping("duplicates", map[string]any{kind: []any{record, record}}), nil)
+			if err == nil || strings.Contains(strings.ToLower(err.Error()), "unrecorded") {
+				t.Fatalf("duplicate identity error = %v", err)
+			}
+		})
+	}
+}
+
 func TestFinalIdentitiesAreCheckedAfterApplicationResolution(t *testing.T) {
 	for _, kind := range []string{"backends", "profiles", "prompts"} {
 		for _, namespace := range []string{"", "*"} {
@@ -452,7 +496,7 @@ func TestLoadComposesLiteralKeysAndEffectivePresence(t *testing.T) {
 		t.Fatalf("recursive overlay failed: %+v", provider)
 	}
 	backend := loaded.result.Config.Backends[0]
-	if backend.QueueCapacity == nil || *backend.QueueCapacity != 0 || loaded.backends["local.v1"]["queue_capacity"] != fieldValue {
+	if backend.QueueCapacity == nil || *backend.QueueCapacity != 0 {
 		t.Fatalf("explicit zero queue capacity was lost: %+v", backend)
 	}
 	if _, err := loaded.registry.GetBackend("base/local.v1"); err != nil {
@@ -534,17 +578,22 @@ func TestLoadInterpretsBackendNormalizationAndNullDefault(t *testing.T) {
 		t.Fatalf("backend normalization/default was not applied: %+v", backend)
 	}
 	composed := loaded.result.Config.Backends[0]
-	if composed.Endpoint == nil || *composed.Endpoint != " HTTP://localhost:8080/v1 " ||
+	if composed.Endpoint == nil || *composed.Endpoint != "http://localhost:8080/v1" ||
-		composed.APIKeyEnv == nil || *composed.APIKeyEnv != " TOKEN_NAME " || composed.QueueCapacity != nil {
+		composed.APIKeyEnv == nil || *composed.APIKeyEnv != "TOKEN_NAME" || composed.QueueCapacity == nil || *composed.QueueCapacity != 1024 {
-		t.Fatalf("composed backend was changed: %+v", composed)
+		t.Fatalf("resolved backend was not normalized: %+v", composed)
-	}
-	if loaded.backends["local"]["queue_capacity"] != fieldNull {
-		t.Fatalf("explicit null was not retained: %+v", loaded.backends["local"])
 	}
 	field, found := loaded.result.Metadata().Lookup(configkit.Keys("backends").Index(0).Key("endpoint"))
-	if !found || field.Origin.Operation == configkit.ChangeNormalization || len(field.Origin.Locations) == 0 {
+	if !found || field.Origin.Operation != configkit.ChangeNormalization {
 		t.Fatalf("endpoint origin was not preserved: %+v", field)
 	}
+	field, found = loaded.result.Metadata().Lookup(configkit.Keys("backends").Index(0).Key("queue_capacity"))
+	if !found || field.Origin.Operation != configkit.ChangeDerivedDefault {
+		t.Fatalf("queue capacity default was not recorded: %+v", field)
+	}
+	field, found = loaded.result.Metadata().Lookup(configkit.Keys("backends").Index(0).Key("concurrency_limit"))
+	if !found || field.Origin.Operation == configkit.ChangeNormalization || field.Origin.Operation == configkit.ChangeDerivedDefault {
+		t.Fatalf("unchanged concurrency acquired a resolution record: %+v", field)
+	}
 }
 
 func TestLoadBackendSmokeTestsOmissionAndNull(t *testing.T) {
@@ -711,7 +760,7 @@ func TestLoadDefaultsAbsentQueueCapacity(t *testing.T) {
 		t.Fatal(err)
 	}
 	backend, err := loaded.GetBackend("local")
-	if err != nil || backend.APIKeyEnv != "" || backend.QueueCapacity != 1024 || loaded.result.Config.Backends[0].QueueCapacity != nil || loaded.backends["local"]["queue_capacity"] != fieldAbsent {
+	if err != nil || backend.APIKeyEnv != "" || backend.QueueCapacity != 1024 || loaded.result.Config.Backends[0].QueueCapacity == nil || *loaded.result.Config.Backends[0].QueueCapacity != 1024 {
 		t.Fatalf("absent queue capacity did not receive its default: %+v", backend)
 	}
 }

internal/configuration/prompts.go

@@ -28,44 +28,6 @@ type promptEntry struct {
 	messages          []*template.Template
 }
 
-func interpretPrompts(source []promptConfig) []promptConfig {
-	if source == nil {
-		return nil
-	}
-	prompts := append([]promptConfig{}, source...)
-	for index := range prompts {
-		definition := &prompts[index]
-		for _, value := range []**string{&definition.Description, &definition.SessionID} {
-			if *value != nil {
-				normalized := strings.TrimSpace(**value)
-				*value = &normalized
-			}
-		}
-		if definition.Inputs != nil {
-			definition.Inputs = append([]promptInputConfig{}, definition.Inputs...)
-			for index := range definition.Inputs {
-				input := &definition.Inputs[index]
-				input.Name = strings.TrimSpace(input.Name)
-				for _, value := range []**string{&input.ContentType, &input.Description} {
-					if *value != nil {
-						normalized := strings.TrimSpace(**value)
-						*value = &normalized
-					}
-				}
-			}
-		}
-		if definition.Output != nil {
-			output := *definition.Output
-			definition.Output = &output
-			if output.SchemaPath != nil {
-				normalized := strings.TrimSpace(*output.SchemaPath)
-				output.SchemaPath = &normalized
-			}
-		}
-	}
-	return prompts
-}
-
 func (state *loaded) materializePrompts() error {
 	state.prompts = make(map[string]*promptEntry)
 	var metadata *configkit.Metadata
@@ -76,7 +38,7 @@ func (state *loaded) materializePrompts() error {
 		}
 		return metadata.Lookup(path)
 	}
-	for _, resources := range resourceSets(&state.interpreted) {
+	for _, resources := range resourceSets(&state.result.Config) {
 		for index, raw := range resources.prompts {
 			promptBase := resources.bases.prompts.Index(index)
 			if strings.TrimSpace(raw.ID) == "" {
@@ -110,107 +72,21 @@ func (state *loaded) materializePrompt(id string, raw promptConfig, base configk
 	if raw.SessionID != nil {
 		definition.SessionID = *raw.SessionID
 	}
-	seenInputs := make(map[string]bool, len(raw.Inputs))
+	inputs, inputMetadata, err := state.capturePromptInputs(id, raw.Inputs, base)
-	definition.Inputs = make([]domain.PromptInput, 0, len(raw.Inputs))
+	if err != nil {
-	entry := &promptEntry{
+		return nil, err
-		messages:          make([]*template.Template, 0, len(raw.Messages)),
-		requirementInputs: make([]prompt.InputMetadata, 0, len(raw.Inputs)),
 	}
-	for index, input := range raw.Inputs {
+	messages, compiledMessages, err := state.capturePromptMessages(raw.Messages, base, lookupOrigin)
-		path := base.Key("inputs").Index(index)
+	if err != nil {
-		if input.Name == "" {
+		return nil, err
-			return nil, fmt.Errorf("%s: input name is required", path.Key("name"))
-		}
-		if seenInputs[input.Name] {
-			return nil, fmt.Errorf("%s: input name is duplicated", path.Key("name"))
-		}
-		seenInputs[input.Name] = true
-		contentType := ""
-		if input.ContentType != nil {
-			contentType = *input.ContentType
-		}
-		description := ""
-		if input.Description != nil {
-			description = *input.Description
-		}
-		definition.Inputs = append(definition.Inputs, domain.PromptInput{
-			Name: input.Name, Required: input.Required, ContentType: contentType, Description: description,
-		})
-		presence := state.promptMetadata[id][index]
-		metadata := prompt.InputMetadata{Name: input.Name, Required: input.Required}
-		if presence.contentType == fieldValue {
-			metadata.ContentType = stringPointer(contentType)
-		}
-		if presence.description == fieldValue {
-			metadata.Description = stringPointer(description)
-		}
-		entry.requirementInputs = append(entry.requirementInputs, metadata)
 	}
-	definition.Templates = make([]domain.PromptMessageTemplate, 0, len(raw.Messages))
+	contract, err := capturePromptOutput(raw.Output, base)
-	for index, message := range raw.Messages {
+	if err != nil {
-		path := base.Key("messages").Index(index)
+		return nil, err
-		if message.Role == nil {
-			return nil, fmt.Errorf("%s: role is required", path.Key("role"))
-		}
-		role, err := domain.NormalizeMessageRole(*message.Role)
-		if err != nil {
-			return nil, fmt.Errorf("%s: %w", path.Key("role"), err)
-		}
-		if (message.Content != nil) == (message.ContentFile != nil) {
-			return nil, fmt.Errorf("%s: exactly one of content or content_file is required", path)
-		}
-		content := ""
-		if message.Content != nil {
-			content = *message.Content
-		} else {
-			var err error
-			content, err = state.readContent(path.Key("content_file"), *message.ContentFile, lookupOrigin)
-			if err != nil {
-				return nil, err
-			}
-		}
-		var control *domain.CacheControl
-		if message.CacheControl != nil {
-			if message.CacheControl.Type == nil {
-				return nil, fmt.Errorf("%s: type is required", path.Key("cache_control").Key("type"))
-			}
-			control = &domain.CacheControl{Type: domain.CacheControlType(*message.CacheControl.Type)}
-			if message.CacheControl.TTL != nil {
-				control.TTL = *message.CacheControl.TTL
-			}
-			var err error
-			control, err = domain.NormalizeCacheControl(control)
-			if err != nil {
-				return nil, fmt.Errorf("%s: %w", path.Key("cache_control"), err)
-			}
-		}
-		compiled, err := prompt.CompileTemplate(fmt.Sprintf("msg_%d", index), content)
-		if err != nil {
-			return nil, fmt.Errorf("%s: invalid template syntax: %w", path, err)
-		}
-		entry.messages = append(entry.messages, compiled)
-		definition.Templates = append(definition.Templates, domain.PromptMessageTemplate{
-			Role: role, Content: content, CacheControl: control,
-		})
 	}
-	if raw.Output == nil {
+	definition.Inputs = inputs
-		return nil, fmt.Errorf("%s: output is required", base.Key("output"))
+	definition.Templates = messages
-	}
+	entry := &promptEntry{requirementInputs: inputMetadata, messages: compiledMessages}
-	if raw.Output.Format == nil || raw.Output.ValidationMode == nil {
-		return nil, fmt.Errorf("%s: format and validation_mode are required", base.Key("output"))
-	}
-	contract := domain.OutputContract{
-		Format:         domain.OutputFormat(*raw.Output.Format),
-		ValidationMode: domain.ValidationMode(*raw.Output.ValidationMode),
-		RepairAttempts: raw.Output.RepairAttempts,
-	}
-	if raw.Output.SchemaPath != nil {
-		contract.SchemaPath = *raw.Output.SchemaPath
-	}
-	if err := domain.ValidateOutputContract(contract); err != nil {
-		return nil, fmt.Errorf("%s: invalid output contract: %w", base.Key("output"), err)
-	}
-	definition.OutputFormat = contract.Format
 	definition.Validation = contract
 	if raw.SessionID != nil {
 		var err error
@@ -233,6 +109,113 @@ func (state *loaded) materializePrompt(id string, raw promptConfig, base configk
 	return entry, nil
 }
 
+func (state *loaded) capturePromptInputs(id string, rawInputs []promptInputConfig, base configkit.Path) ([]domain.PromptInput, []prompt.InputMetadata, error) {
+	seenInputs := make(map[string]bool, len(rawInputs))
+	inputs := make([]domain.PromptInput, 0, len(rawInputs))
+	metadata := make([]prompt.InputMetadata, 0, len(rawInputs))
+	for index, input := range rawInputs {
+		path := base.Key("inputs").Index(index)
+		if input.Name == "" {
+			return nil, nil, fmt.Errorf("%s: input name is required", path.Key("name"))
+		}
+		if seenInputs[input.Name] {
+			return nil, nil, fmt.Errorf("%s: input name is duplicated", path.Key("name"))
+		}
+		seenInputs[input.Name] = true
+		contentType := ""
+		if input.ContentType != nil {
+			contentType = *input.ContentType
+		}
+		description := ""
+		if input.Description != nil {
+			description = *input.Description
+		}
+		inputs = append(inputs, domain.PromptInput{
+			Name: input.Name, Required: input.Required, ContentType: contentType, Description: description,
+		})
+		presence := state.promptMetadata[id][index]
+		item := prompt.InputMetadata{Name: input.Name, Required: input.Required}
+		if presence.contentType == fieldValue {
+			item.ContentType = stringPointer(contentType)
+		}
+		if presence.description == fieldValue {
+			item.Description = stringPointer(description)
+		}
+		metadata = append(metadata, item)
+	}
+	return inputs, metadata, nil
+}
+
+func (state *loaded) capturePromptMessages(rawMessages []promptMessageConfig, base configkit.Path, lookupOrigin func(configkit.Path) (configkit.FieldInfo, bool)) ([]domain.PromptMessageTemplate, []*template.Template, error) {
+	templates := make([]domain.PromptMessageTemplate, 0, len(rawMessages))
+	compiledMessages := make([]*template.Template, 0, len(rawMessages))
+	for index, message := range rawMessages {
+		path := base.Key("messages").Index(index)
+		if message.Role == nil {
+			return nil, nil, fmt.Errorf("%s: role is required", path.Key("role"))
+		}
+		if _, err := domain.NormalizeMessageRole(*message.Role); err != nil {
+			return nil, nil, fmt.Errorf("%s: %w", path.Key("role"), err)
+		}
+		if (message.Content != nil) == (message.ContentFile != nil) {
+			return nil, nil, fmt.Errorf("%s: exactly one of content or content_file is required", path)
+		}
+		content := ""
+		if message.Content != nil {
+			content = *message.Content
+		} else {
+			var err error
+			content, err = state.readContent(path.Key("content_file"), *message.ContentFile, lookupOrigin)
+			if err != nil {
+				return nil, nil, err
+			}
+		}
+		var control *domain.CacheControl
+		if message.CacheControl != nil {
+			if message.CacheControl.Type == nil {
+				return nil, nil, fmt.Errorf("%s: type is required", path.Key("cache_control").Key("type"))
+			}
+			control = &domain.CacheControl{Type: domain.CacheControlType(*message.CacheControl.Type)}
+			if message.CacheControl.TTL != nil {
+				control.TTL = *message.CacheControl.TTL
+			}
+			if _, err := domain.NormalizeCacheControl(control); err != nil {
+				return nil, nil, fmt.Errorf("%s: %w", path.Key("cache_control"), err)
+			}
+		}
+		compiled, err := prompt.CompileTemplate(fmt.Sprintf("msg_%d", index), content)
+		if err != nil {
+			return nil, nil, fmt.Errorf("%s: invalid template syntax: %w", path, err)
+		}
+		compiledMessages = append(compiledMessages, compiled)
+		templates = append(templates, domain.PromptMessageTemplate{
+			Role: *message.Role, Content: content, CacheControl: control,
+		})
+	}
+	return templates, compiledMessages, nil
+}
+
+func capturePromptOutput(output *promptOutputConfig, base configkit.Path) (domain.OutputContract, error) {
+	if output == nil {
+		return domain.OutputContract{}, fmt.Errorf("%s: output is required", base.Key("output"))
+	}
+	if output.Format == nil || output.ValidationMode == nil {
+		return domain.OutputContract{}, fmt.Errorf("%s: format and validation_mode are required", base.Key("output"))
+	}
+	contract := domain.OutputContract{
+		Format:         domain.OutputFormat(*output.Format),
+		ValidationMode: domain.ValidationMode(*output.ValidationMode),
+		RepairAttempts: output.RepairAttempts,
+	}
+	if output.SchemaPath != nil {
+		contract.SchemaPath = *output.SchemaPath
+	}
+	if err := domain.ValidateOutputContract(contract); err != nil {
+		return domain.OutputContract{}, fmt.Errorf("%s: invalid output contract: %w", base.Key("output"), err)
+	}
+	return contract, nil
+}
+
 func stringPointer(value string) *string {
 	copy := value
 	return &copy
@@ -346,12 +329,6 @@ func (state *loaded) GetPromptInspection(ctx context.Context, id string) (*domai
 	return ownPromptInspection(entry.inspection), nil
 }
 
-// GetPromptDefinition implements the runner's prompt lookup boundary.
-func (state *loaded) GetPromptDefinition(ctx context.Context, id string) (*domain.PromptDefinition, error) {
-	definition, _, err := state.GetPromptSnapshot(ctx, id)
-	return definition, err
-}
-
 // GetCompiledTemplates returns construction-time parses for one prompt ID.
 func (state *loaded) GetCompiledTemplates(id string) (prompt.CompiledTemplates, bool) {
 	if state == nil {

internal/configuration/prompts_test.go

@@ -16,7 +16,7 @@ import (
 
 func TestLoadCapturesInheritedImportedContent(t *testing.T) {
 	files := fstest.MapFS{
-		"app/main.yaml":         {Data: []byte("config:\n  imports:\n    - path: ../catalog/base.yaml\n      required: true\ncollections:\n  docs:\n    prompts:\n      - id: child\n        extends: {id: base}\n  other:\n    prompts:\n      - id: child\n        messages:\n          - role: user\n            content_file: ./body.md\n        output:\n          format: text\n          validation_mode: none\n")},
+		"app/main.yaml":         {Data: []byte("config:\n  imports:\n    - path: ../catalog/base.yaml\n      required: true\ncollections:\n  docs:\n    prompts:\n      - id: child\n        extends: {id: base}\n        description: ' description '\n  other:\n    prompts:\n      - id: child\n        messages:\n          - role: user\n            content_file: ./body.md\n        output:\n          format: text\n          validation_mode: none\n")},
 		"app/body.md":           {Data: []byte("Replacement {{.name}}")},
 		"catalog/base.yaml":     {Data: []byte("collections:\n  docs:\n    release_version: r1\n    prompts:\n      - id: base\n        description: ' description '\n        session_id: ' session '\n        inputs:\n          - name: ' document '\n            content_type: ' text/plain '\n            description: ' document source '\n        messages:\n          - role: ' USER '\n            cache_control:\n              type: ' ephemeral '\n              ttl: ' 1h '\n            content_file: ./body.md\n        output:\n          format: text\n          validation_mode: basic\n")},
 		"catalog/body.md":       {Data: []byte("Captured {{.name}}")},
@@ -60,9 +60,9 @@ func TestLoadCapturesInheritedImportedContent(t *testing.T) {
 		t.Fatal("inherited prompt missing from effective list")
 	}
 	composed := state.result.Config.Collections["docs"].Prompts[childIndex]
-	if *composed.Description != " description " || *composed.SessionID != " session " || composed.Inputs[0].Name != " document " ||
+	if *composed.Description != "description" || *composed.SessionID != "session" || composed.Inputs[0].Name != "document" ||
-		*composed.Inputs[0].ContentType != " text/plain " || *composed.Inputs[0].Description != " document source " {
+		*composed.Inputs[0].ContentType != "text/plain" || *composed.Inputs[0].Description != "document source" {
-		t.Fatalf("composed metadata was changed: %+v", composed)
+		t.Fatalf("resolved metadata was not normalized: %+v", composed)
 	}
 	field, ok := state.result.Metadata().Lookup(configkit.Keys("collections", "docs", "prompts").Index(childIndex).Key("messages").Index(0).Key("content_file"))
 	if !ok || len(field.Origin.Locations) != 1 {

internal/configuration/resolve_prompts.go

@@ -0,0 +1,68 @@
+package configuration
+
+import (
+	"strings"
+
+	"go.maximumdirect.net/configkit"
+	"go.maximumdirect.net/promptkit/internal/domain"
+)
+
+func resolvePrompts(entries []promptConfig, base configkit.Path, resolution *configkit.Resolution) {
+	if !eligibleResourceList(entries, func(v promptConfig) string { return v.ID }) {
+		return
+	}
+	for i := range entries {
+		entry := &entries[i]
+		path := base.Index(i)
+		for _, field := range []struct {
+			value **string
+			name  string
+		}{{&entry.Description, "description"}, {&entry.SessionID, "session_id"}} {
+			if *field.value != nil {
+				recordStringNormalization(field.value, path.Key(field.name), resolution, strings.TrimSpace(**field.value))
+			}
+		}
+		for j := range entry.Inputs {
+			input := &entry.Inputs[j]
+			inputPath := path.Key("inputs").Index(j)
+			if normalized := strings.TrimSpace(input.Name); normalized != input.Name {
+				configkit.Normalize(resolution, inputPath.Key("name"), &input.Name, normalized, "Normalize input name")
+			}
+			for _, field := range []struct {
+				value **string
+				name  string
+			}{{&input.ContentType, "content_type"}, {&input.Description, "description"}} {
+				if *field.value != nil {
+					recordStringNormalization(field.value, inputPath.Key(field.name), resolution, strings.TrimSpace(**field.value))
+				}
+			}
+		}
+		if entry.Output != nil && entry.Output.SchemaPath != nil {
+			recordStringNormalization(&entry.Output.SchemaPath, path.Key("output").Key("schema_path"), resolution, strings.TrimSpace(*entry.Output.SchemaPath))
+		}
+		for j := range entry.Messages {
+			message := &entry.Messages[j]
+			messagePath := path.Key("messages").Index(j)
+			if message.Role != nil {
+				if value, err := domain.NormalizeMessageRole(*message.Role); err == nil {
+					recordStringNormalization(&message.Role, messagePath.Key("role"), resolution, value)
+				}
+			}
+			if message.CacheControl == nil || message.CacheControl.Type == nil {
+				continue
+			}
+			cache := message.CacheControl
+			control := &domain.CacheControl{Type: domain.CacheControlType(*cache.Type)}
+			if cache.TTL != nil {
+				control.TTL = *cache.TTL
+			}
+			if normalized, err := domain.NormalizeCacheControl(control); err == nil {
+				cachePath := messagePath.Key("cache_control")
+				recordStringNormalization(&cache.Type, cachePath.Key("type"), resolution, string(normalized.Type))
+				if cache.TTL != nil {
+					recordStringNormalization(&cache.TTL, cachePath.Key("ttl"), resolution, normalized.TTL)
+				}
+			}
+		}
+	}
+}

internal/configuration/resolve_targets.go

@@ -0,0 +1,102 @@
+package configuration
+
+import (
+	"net/http"
+	"strings"
+
+	"go.maximumdirect.net/configkit"
+	"go.maximumdirect.net/promptkit/internal/domain"
+)
+
+func resolveBackends(entries []backendConfig, base configkit.Path, resolution *configkit.Resolution) {
+	if !eligibleResourceList(entries, func(v backendConfig) string { return v.ID }) {
+		return
+	}
+	for i := range entries {
+		entry := &entries[i]
+		path := base.Index(i)
+		if entry.Endpoint != nil {
+			if normalized, err := domain.NormalizeOpenAICompatibleBaseEndpoint(*entry.Endpoint); err == nil {
+				recordStringNormalization(&entry.Endpoint, path.Key("endpoint"), resolution, normalized)
+			}
+		}
+		if entry.APIKeyEnv != nil {
+			recordStringNormalization(&entry.APIKeyEnv, path.Key("api_key_env"), resolution, strings.TrimSpace(*entry.APIKeyEnv))
+		}
+		if entry.ConcurrencyLimit != nil && *entry.ConcurrencyLimit > 0 && entry.QueueCapacity == nil {
+			capacity := 1024
+			entry.QueueCapacity = &capacity
+			resolution.RecordDerivedDefault(path.Key("queue_capacity"), "Derive queue capacity", path.Key("concurrency_limit"))
+		}
+		if entry.SmokeTests == nil {
+			continue
+		}
+		smoke := entry.SmokeTests
+		smokePath := path.Key("smoke_tests")
+		if smoke.Reachability != nil {
+			resolveDiagnosticEndpoint(&smoke.Reachability.Endpoint, smokePath.Key("reachability").Key("endpoint"), resolution)
+		}
+		if smoke.Authentication != nil {
+			auth := smoke.Authentication
+			authPath := smokePath.Key("authentication")
+			if auth.Kind != nil {
+				recordStringNormalization(&auth.Kind, authPath.Key("kind"), resolution, strings.ToLower(strings.TrimSpace(*auth.Kind)))
+			}
+			resolveDiagnosticEndpoint(&auth.Endpoint, authPath.Key("endpoint"), resolution)
+		}
+	}
+}
+
+func diagnosticEndpointValid(value string) bool {
+	normalized := strings.TrimSpace(value)
+	request, err := http.NewRequest(http.MethodGet, normalized, nil)
+	return normalized != "" && err == nil && request.URL != nil && (strings.EqualFold(request.URL.Scheme, "http") || strings.EqualFold(request.URL.Scheme, "https")) && request.URL.Hostname() != ""
+}
+
+func validateBackendEndpoints(entry backendConfig, path configkit.Path, validation *configkit.Validation) {
+	if entry.Endpoint != nil {
+		if _, err := domain.NormalizeOpenAICompatibleBaseEndpoint(*entry.Endpoint); err != nil {
+			validation.Error(path.Key("endpoint"), err.Error())
+		}
+	}
+	if entry.SmokeTests == nil {
+		return
+	}
+	smoke := entry.SmokeTests
+	path = path.Key("smoke_tests")
+	if smoke.Reachability != nil && smoke.Reachability.Endpoint != nil && !diagnosticEndpointValid(*smoke.Reachability.Endpoint) {
+		validation.Error(path.Key("reachability").Key("endpoint"), "diagnostic endpoint must be an absolute HTTP(S) URL with a host")
+	}
+	if smoke.Authentication != nil && smoke.Authentication.Endpoint != nil && !diagnosticEndpointValid(*smoke.Authentication.Endpoint) {
+		validation.Error(path.Key("authentication").Key("endpoint"), "diagnostic endpoint must be an absolute HTTP(S) URL with a host")
+	}
+}
+
+func resolveDiagnosticEndpoint(value **string, path configkit.Path, resolution *configkit.Resolution) {
+	if *value != nil && diagnosticEndpointValid(**value) {
+		recordStringNormalization(value, path, resolution, strings.TrimSpace(**value))
+	}
+}
+
+func resolveProfiles(entries []profileConfig, base configkit.Path, resolution *configkit.Resolution) {
+	if !eligibleResourceList(entries, func(v profileConfig) string { return v.ID }) {
+		return
+	}
+	for i := range entries {
+		entry := &entries[i]
+		path := base.Index(i)
+		if entry.Endpoint != nil && *entry.Endpoint != "" {
+			if normalized, err := domain.NormalizeOpenAICompatibleBaseEndpoint(*entry.Endpoint); err == nil {
+				recordStringNormalization(&entry.Endpoint, path.Key("endpoint"), resolution, normalized)
+			}
+		}
+		for _, field := range []struct {
+			value **string
+			name  string
+		}{{&entry.ServiceTier, "service_tier"}, {&entry.ReasoningEffort, "reasoning_effort"}, {&entry.APIKeyEnv, "api_key_env"}} {
+			if *field.value != nil {
+				recordStringNormalization(field.value, path.Key(field.name), resolution, strings.TrimSpace(**field.value))
+			}
+		}
+	}
+}

internal/configuration/targets.go

@@ -12,114 +12,120 @@ import (
 )
 
 func (state *loaded) buildExecutionProfiles() error {
-	backendConfigs := indexedBackends(&state.interpreted)
+	backendConfigs := indexedBackends(&state.result.Config)
-	profileConfigs := indexedProfiles(&state.interpreted)
+	profileConfigs := indexedProfiles(&state.result.Config)
 	definitions := make(map[string]domain.Backend, len(backendConfigs))
 	for _, id := range sortedKeys(backendConfigs) {
 		config := backendConfigs[id]
-		definition := domain.Backend{ID: id, ExtraParams: config.ExtraParams}
+		definitions[id] = captureBackend(id, config)
-		if config.SmokeTests != nil {
-			smokeTests := &domain.BackendSmokeTestConfig{DefaultProfile: config.SmokeTests.DefaultProfile}
-			if config.SmokeTests.Reachability != nil {
-				smokeTests.Reachability = &domain.ReachabilityProbeConfig{Endpoint: config.SmokeTests.Reachability.Endpoint}
-			}
-			if config.SmokeTests.Authentication != nil {
-				smokeTests.Authentication = &domain.AuthenticationProbeConfig{
-					Kind:     config.SmokeTests.Authentication.Kind,
-					Endpoint: config.SmokeTests.Authentication.Endpoint,
-				}
-			}
-			definition.SmokeTests = smokeTests
-		}
-		if config.Endpoint != nil {
-			definition.Endpoint = *config.Endpoint
-		}
-		if config.APIKeyEnv != nil {
-			definition.APIKeyEnv = *config.APIKeyEnv
-		}
-		if config.ConcurrencyLimit != nil {
-			definition.ConcurrencyLimit = *config.ConcurrencyLimit
-		}
-		if config.QueueCapacity != nil {
-			definition.QueueCapacity = *config.QueueCapacity
-			definition.QueueCapacitySet = definition.ConcurrencyLimit > 0
-		}
-		definitions[id] = definition
 	}
-	registry, err := backend.NewEffectiveRegistry(definitions)
+	state.registry = backend.NewEffectiveRegistry(definitions)
-	if err != nil {
-		return err
-	}
-	state.registry = registry
 	state.indexedProfiles = make(map[string]domain.ExecutionProfile, len(profileConfigs))
 	for _, id := range sortedKeys(profileConfigs) {
 		config := profileConfigs[id]
-		fields := state.profiles[id]
+		profile, err := captureExecutionProfile(id, config, state.profiles[id], state.registry)
-		target := defaults.ExecutionTargetDefault()
+		if err != nil {
-		if config.Backend != nil && *config.Backend != "" {
+			return err
-			selected, err := registry.GetBackend(*config.Backend)
-			if err != nil {
-				return fmt.Errorf("profile %q backend: %w", id, err)
-			}
-			target.BackendID = selected.ID
-			target.Endpoint = selected.Endpoint
-			target.APIKeyEnv = selected.APIKeyEnv
-			target.ExtraParams = selected.ExtraParams
 		}
-		presence := domain.ExecutionTargetPresence{}
-		if fields["endpoint"] != fieldAbsent {
-			target.Endpoint = valueOrZero(config.Endpoint)
-		}
-		if fields["model"] != fieldAbsent {
-			target.Model = valueOrZero(config.Model)
-		}
-		if fields["temperature"] != fieldAbsent {
-			target.Temperature = valueOrZero(config.Temperature)
-			presence.Temperature = fields["temperature"] == fieldValue
-		}
-		if fields["top_p"] != fieldAbsent {
-			target.TopP = valueOrZero(config.TopP)
-			presence.TopP = fields["top_p"] == fieldValue
-		}
-		if fields["max_tokens"] != fieldAbsent {
-			target.MaxTokens = valueOrZero(config.MaxTokens)
-			presence.MaxTokens = fields["max_tokens"] == fieldValue
-		}
-		if fields["timeout_seconds"] == fieldValue {
-			target.TimeoutSeconds = valueOrZero(config.TimeoutSeconds)
-			presence.TimeoutSeconds = true
-		}
-		if fields["service_tier"] != fieldAbsent {
-			target.ServiceTier = valueOrZero(config.ServiceTier)
-		}
-		if fields["reasoning_effort"] != fieldAbsent {
-			target.ReasoningEffort = valueOrZero(config.ReasoningEffort)
-		}
-		if fields["api_key_env"] != fieldAbsent {
-			target.APIKeyEnv = valueOrZero(config.APIKeyEnv)
-		}
-		if fields["api_key_required"] != fieldAbsent {
-			target.APIKeyRequired = valueOrZero(config.APIKeyRequired)
-		}
-		if target.APIKeyRequired && fields["api_key_env"] == fieldAbsent {
-			target.APIKeyEnv = ""
-		}
-		switch fields["extra_params"] {
-		case fieldNull:
-			target.ExtraParams = nil
-		case fieldValue:
-			merged, err := overlayProviderMap(target.ExtraParams, config.ExtraParams)
-			if err != nil {
-				return fmt.Errorf("profile %q extra parameters: %w", id, err)
-			}
-			target.ExtraParams = merged
-		}
-		profile := domain.ExecutionProfile{ID: id, ResolvedTarget: &target, TargetPresence: presence}
 		state.indexedProfiles[id] = profile
 	}
 	return nil
 }
 
+func captureBackend(id string, config backendConfig) domain.Backend {
+	definition := domain.Backend{ID: id, ExtraParams: config.ExtraParams}
+	if config.SmokeTests != nil {
+		smokeTests := &domain.BackendSmokeTestConfig{DefaultProfile: config.SmokeTests.DefaultProfile}
+		if config.SmokeTests.Reachability != nil {
+			smokeTests.Reachability = &domain.ReachabilityProbeConfig{Endpoint: config.SmokeTests.Reachability.Endpoint}
+		}
+		if config.SmokeTests.Authentication != nil {
+			smokeTests.Authentication = &domain.AuthenticationProbeConfig{
+				Kind:     config.SmokeTests.Authentication.Kind,
+				Endpoint: config.SmokeTests.Authentication.Endpoint,
+			}
+		}
+		definition.SmokeTests = smokeTests
+	}
+	if config.Endpoint != nil {
+		definition.Endpoint = *config.Endpoint
+	}
+	if config.APIKeyEnv != nil {
+		definition.APIKeyEnv = *config.APIKeyEnv
+	}
+	if config.ConcurrencyLimit != nil {
+		definition.ConcurrencyLimit = *config.ConcurrencyLimit
+	}
+	if config.QueueCapacity != nil {
+		definition.QueueCapacity = *config.QueueCapacity
+	}
+	return definition
+}
+
+func captureExecutionProfile(id string, config profileConfig, fields map[string]fieldState, registry *backend.Registry) (domain.ExecutionProfile, error) {
+	target := defaults.ExecutionTargetDefault()
+	if config.Backend != nil && *config.Backend != "" {
+		selected, err := registry.GetBackend(*config.Backend)
+		if err != nil {
+			return domain.ExecutionProfile{}, fmt.Errorf("profile %q backend: %w", id, err)
+		}
+		target.BackendID = selected.ID
+		target.Endpoint = selected.Endpoint
+		target.APIKeyEnv = selected.APIKeyEnv
+		target.ExtraParams = selected.ExtraParams
+	}
+	presence := domain.ExecutionTargetPresence{}
+	if fields["endpoint"] != fieldAbsent {
+		target.Endpoint = valueOrZero(config.Endpoint)
+	}
+	if fields["model"] != fieldAbsent {
+		target.Model = valueOrZero(config.Model)
+	}
+	if fields["temperature"] != fieldAbsent {
+		target.Temperature = valueOrZero(config.Temperature)
+		presence.Temperature = fields["temperature"] == fieldValue
+	}
+	if fields["top_p"] != fieldAbsent {
+		target.TopP = valueOrZero(config.TopP)
+		presence.TopP = fields["top_p"] == fieldValue
+	}
+	if fields["max_tokens"] != fieldAbsent {
+		target.MaxTokens = valueOrZero(config.MaxTokens)
+		presence.MaxTokens = fields["max_tokens"] == fieldValue
+	}
+	if fields["timeout_seconds"] == fieldValue {
+		target.TimeoutSeconds = valueOrZero(config.TimeoutSeconds)
+		presence.TimeoutSeconds = true
+	}
+	if fields["service_tier"] != fieldAbsent {
+		target.ServiceTier = valueOrZero(config.ServiceTier)
+	}
+	if fields["reasoning_effort"] != fieldAbsent {
+		target.ReasoningEffort = valueOrZero(config.ReasoningEffort)
+	}
+	if fields["api_key_env"] != fieldAbsent {
+		target.APIKeyEnv = valueOrZero(config.APIKeyEnv)
+	}
+	if fields["api_key_required"] != fieldAbsent {
+		target.APIKeyRequired = valueOrZero(config.APIKeyRequired)
+	}
+	if target.APIKeyRequired && fields["api_key_env"] == fieldAbsent {
+		target.APIKeyEnv = ""
+	}
+	switch fields["extra_params"] {
+	case fieldNull:
+		target.ExtraParams = nil
+	case fieldValue:
+		merged, err := overlayProviderMap(target.ExtraParams, config.ExtraParams)
+		if err != nil {
+			return domain.ExecutionProfile{}, fmt.Errorf("profile %q extra parameters: %w", id, err)
+		}
+		target.ExtraParams = merged
+	}
+	profile := domain.ExecutionProfile{ID: id, ResolvedTarget: &target, TargetPresence: presence}
+	return profile, nil
+}
+
 func valueOrZero[T any](value *T) T {
 	if value == nil {
 		var zero T
@@ -138,24 +144,33 @@ func overlayProviderMap(lower, upper map[string]any) (map[string]any, error) {
 	if merged == nil {
 		merged = make(map[string]any)
 	}
+	if err := overlayOwnedProviderMap(merged, upper); err != nil {
+		return nil, err
+	}
+	return merged, nil
+}
+
+func overlayOwnedProviderMap(merged, upper map[string]any) error {
 	for key, value := range upper {
 		if child, ok := value.(map[string]any); ok {
 			if existing, ok := merged[key].(map[string]any); ok {
-				combined, err := overlayProviderMap(existing, child)
+				if existing == nil {
-				if err != nil {
+					existing = make(map[string]any)
-					return nil, err
+					merged[key] = existing
+				}
+				if err := overlayOwnedProviderMap(existing, child); err != nil {
+					return err
 				}
-				merged[key] = combined
 				continue
 			}
 		}
 		copied, err := jsonvalue.Copy(value)
 		if err != nil {
-			return nil, err
+			return err
 		}
 		merged[key] = copied
 	}
-	return merged, nil
+	return nil
 }
 
 func (state *loaded) lookupProfile(ctx context.Context, id string) (domain.ExecutionProfile, error) {
@@ -180,11 +195,7 @@ func (state *loaded) GetProfile(ctx context.Context, id string) (*domain.Executi
 		return nil, err
 	}
 	target := *profile.ResolvedTarget
-	params, err := jsonvalue.CopyMap(target.ExtraParams)
+	target.ExtraParams = jsonvalue.CloneTrusted(target.ExtraParams).(map[string]any)
-	if err != nil {
-		return nil, err
-	}
-	target.ExtraParams = params
 	profile.ResolvedTarget = &target
 	return &profile, nil
 }

internal/configuration/targets_test.go

@@ -42,6 +42,28 @@ func TestLoadIndexesIdentifiedTargets(t *testing.T) {
 	}
 }
 
+func TestOverlayProviderMapOwnsInputsAndReplacesValues(t *testing.T) {
+	lower := map[string]any{"nested": map[string]any{"keep": "lower", "replace": []any{"old"}, "null": "old"}, "disjoint": []any{"original"}}
+	upper := map[string]any{"nested": map[string]any{"replace": []any{"new"}, "null": nil, "added": map[string]any{"value": "upper"}}}
+	got, err := overlayProviderMap(lower, upper)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := map[string]any{"nested": map[string]any{"keep": "lower", "replace": []any{"new"}, "null": nil, "added": map[string]any{"value": "upper"}}, "disjoint": []any{"original"}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("overlay = %#v", got)
+	}
+	lower["disjoint"].([]any)[0] = "changed"
+	upper["nested"].(map[string]any)["replace"].([]any)[0] = "changed"
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("overlay shares input storage: %#v", got)
+	}
+	got["nested"].(map[string]any)["added"].(map[string]any)["value"] = "changed"
+	if upper["nested"].(map[string]any)["added"].(map[string]any)["value"] != "upper" {
+		t.Fatal("result mutation reached upper")
+	}
+}
+
 func TestRequestCompletesLoadedPartialProfile(t *testing.T) {
 	state, err := load(mapping("partial profile", map[string]any{
 		"profiles": []any{map[string]any{"id": "partial"}},
@@ -53,7 +75,7 @@ func TestRequestCompletesLoadedPartialProfile(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	runner := usecase.NewRunner(state, state, nil, prompt.NewGoRenderer(), nil, nil, nil)
+	runner := usecase.NewRunner(state, state, nil, prompt.NewCompiledRenderer(state), nil, nil, nil)
 	prepared, err := runner.Prepare(context.Background(), domain.RunRequest{
 		PromptID: "example", ProfileID: "partial",
 		Execution: &domain.ExecutionTargetOverride{Endpoint: "https://example.invalid/v1", Model: "request-model"},
@@ -97,7 +119,7 @@ func TestLoadBuildsEffectiveTargetsAfterInheritance(t *testing.T) {
 		t.Fatal(err)
 	}
 	selected, err := state.registry.GetBackend("second")
-	if err != nil || selected.QueueCapacity != 0 || !selected.QueueCapacitySet {
+	if err != nil || selected.QueueCapacity != 0 || selected.ConcurrencyLimit != 2 {
 		t.Fatalf("backend capacity was not preserved: %+v, %v", selected, err)
 	}
 	child, err := state.GetProfile(context.Background(), "child")
@@ -197,10 +219,7 @@ func TestLoadedZeroControlsReachBuiltInRequest(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	client, err := llm.NewOpenAICompatibleClient(llm.OpenAICompatibleConfig{})
+	client := llm.NewOpenAICompatibleClient(llm.OpenAICompatibleConfig{})
-	if err != nil {
-		t.Fatal(err)
-	}
 	_, err = client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hello"}}},
 		Target: *profile.ResolvedTarget, TargetPresence: profile.TargetPresence,

internal/domain/domain.go

@@ -145,7 +145,6 @@ type PromptDefinition struct {
 	SessionID      string                  `yaml:"session_id" json:"session_id,omitempty"`
 	Inputs         []PromptInput           `yaml:"inputs"`
 	Templates      []PromptMessageTemplate `yaml:"templates"`
-	OutputFormat   OutputFormat            `yaml:"output_format"`
 	Validation     OutputContract          `yaml:"validation"`
 }
 
@@ -170,7 +169,6 @@ type PromptInput struct {
 type PromptMessageTemplate struct {
 	Role         string        `yaml:"role"`
 	Content      string        `yaml:"content"`
-	ContentFile  string        `yaml:"content_file"`
 	CacheControl *CacheControl `yaml:"cache_control,omitempty" json:"cache_control,omitempty"`
 }
 
@@ -184,7 +182,6 @@ type Backend struct {
 	SmokeTests       *BackendSmokeTestConfig
 	ConcurrencyLimit int
 	QueueCapacity    int
-	QueueCapacitySet bool
 }
 
 // BackendCapacityPolicy describes normalized run and generation capacity for

internal/domain/resource_identity.go

@@ -31,14 +31,6 @@ func qualifyResourceID(id, namespace string) (string, bool) {
 	return namespace + "/" + id, true
 }
 
-func resourceNamespaceFromID(id string) (string, bool) {
-	if !validResourceID(id) || !strings.Contains(id, "/") {
-		return "", false
-	}
-	namespace, _, _ := strings.Cut(id, "/")
-	return namespace, true
-}
-
 // IsValidResourceID reports whether id is an unqualified resource ID or one
 // valid namespace/local-ID pair.
 func IsValidResourceID(id string) bool { return validResourceID(id) }

internal/domain/resource_identity_test.go

@@ -86,25 +86,3 @@ func TestQualifyResourceID(t *testing.T) {
 		})
 	}
 }
-
-func TestResourceNamespaceFromID(t *testing.T) {
-	tests := []struct {
-		name      string
-		id        string
-		namespace string
-		wantOK    bool
-	}{
-		{name: "qualified", id: "team/item", namespace: "team", wantOK: true},
-		{name: "same-prefix namespace stays distinct", id: "team-extra/item", namespace: "team-extra", wantOK: true},
-		{name: "unqualified", id: "item", wantOK: false},
-		{name: "malformed", id: "team/sub/item", wantOK: false},
-	}
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
-			got, ok := resourceNamespaceFromID(test.id)
-			if got != test.namespace || ok != test.wantOK {
-				t.Fatalf("resourceNamespaceFromID(%q) = (%q, %t), want (%q, %t)", test.id, got, ok, test.namespace, test.wantOK)
-			}
-		})
-	}
-}

internal/domain/session.go

@@ -18,5 +18,5 @@ func NormalizeSessionID(raw string) (string, error) {
 	if length := utf8.RuneCountInString(normalized); length > SessionIDMaxLength {
 		return "", fmt.Errorf("session_id length %d exceeds maximum %d", length, SessionIDMaxLength)
 	}
-	return normalized, nil
+	return strings.Clone(normalized), nil
 }

internal/domain/smoke_diagnostics.go

@@ -112,24 +112,21 @@ type SmokeTestAttempt struct {
 type SmokeTestReason string
 
 const (
-	SmokeTestReasonNone                               SmokeTestReason = ""
+	SmokeTestReasonNone                                SmokeTestReason = ""
-	SmokeTestReasonAuthenticationNotApplicable        SmokeTestReason = "authentication_not_applicable"
+	SmokeTestReasonAuthenticationNotApplicable         SmokeTestReason = "authentication_not_applicable"
-	SmokeTestReasonProbeNotConfigured                 SmokeTestReason = "probe_not_configured"
+	SmokeTestReasonProbeNotConfigured                  SmokeTestReason = "probe_not_configured"
-	SmokeTestReasonHTTPDiagnosticsUnavailable         SmokeTestReason = "http_diagnostics_unavailable"
+	SmokeTestReasonHTTPDiagnosticsUnavailable          SmokeTestReason = "http_diagnostics_unavailable"
-	SmokeTestReasonRequiredCredentialMissing          SmokeTestReason = "required_credential_missing"
+	SmokeTestReasonRequiredCredentialMissing           SmokeTestReason = "required_credential_missing"
-	SmokeTestReasonAuthenticationResponseUnrecognized SmokeTestReason = "authentication_response_unrecognized"
+	SmokeTestReasonAuthenticationResponseUnrecognized  SmokeTestReason = "authentication_response_unrecognized"
+	SmokeTestReasonAuthenticationResponseLimitExceeded SmokeTestReason = "authentication_response_limit_exceeded"
 )
 
 // CloneBackend returns a copy of a backend, including its mutable settings.
-func CloneBackend(backend Backend) (Backend, error) {
+func CloneBackend(backend Backend) Backend {
 	cloned := backend
-	var err error
+	cloned.ExtraParams = jsonvalue.CloneTrusted(backend.ExtraParams).(map[string]any)
-	cloned.ExtraParams, err = jsonvalue.CopyMap(backend.ExtraParams)
-	if err != nil {
-		return Backend{}, err
-	}
 	cloned.SmokeTests = CloneBackendSmokeTestConfig(backend.SmokeTests)
-	return cloned, nil
+	return cloned
 }
 
 // CloneBackendSmokeTestConfig returns an independent copy of optional metadata.
@@ -153,105 +150,6 @@ func CloneBackendSmokeTestConfig(config *BackendSmokeTestConfig) *BackendSmokeTe
 	return &cloned
 }
 
-// CloneSmokeTestRequest returns a copy that owns its optional settings.
-func CloneSmokeTestRequest(request SmokeTestRequest) (SmokeTestRequest, error) {
-	cloned := request
-	cloned.TransientRetries = cloneInt(request.TransientRetries)
-	if request.Execution == nil {
-		return cloned, nil
-	}
-	execution := *request.Execution
-	execution.Temperature = cloneFloat64(request.Execution.Temperature)
-	execution.MaxTokens = cloneInt(request.Execution.MaxTokens)
-	execution.TopP = cloneFloat64(request.Execution.TopP)
-	execution.TimeoutSeconds = cloneInt(request.Execution.TimeoutSeconds)
-	execution.ReasoningEffort = cloneString(request.Execution.ReasoningEffort)
-	var err error
-	execution.ExtraParams, err = jsonvalue.CopyMap(request.Execution.ExtraParams)
-	if err != nil {
-		return SmokeTestRequest{}, err
-	}
-	cloned.Execution = &execution
-	return cloned, nil
-}
-
-// CloneSmokeTestReport returns a copy with independent optional facts and maps.
-func CloneSmokeTestReport(report SmokeTestReport) (SmokeTestReport, error) {
-	cloned := report
-	cloned.Applicable = cloneBool(report.Applicable)
-	cloned.Facts = cloneSmokeTestFacts(report.Facts)
-	cloned.Timing = cloneSmokeTestTiming(report.Timing)
-	var err error
-	cloned.Target.EffectiveSettings.ExtraParams, err = jsonvalue.CopyMap(report.Target.EffectiveSettings.ExtraParams)
-	if err != nil {
-		return SmokeTestReport{}, err
-	}
-	if report.Attempts != nil {
-		cloned.Attempts = make([]SmokeTestAttempt, len(report.Attempts))
-		for index, attempt := range report.Attempts {
-			cloned.Attempts[index] = attempt
-			cloned.Attempts[index].HTTPStatus = cloneInt(attempt.HTTPStatus)
-			cloned.Attempts[index].Facts = cloneSmokeTestFacts(attempt.Facts)
-			cloned.Attempts[index].Timing = cloneSmokeTestTiming(attempt.Timing)
-		}
-	}
-	return cloned, nil
-}
-
-func cloneSmokeTestFacts(facts SmokeTestFacts) SmokeTestFacts {
-	facts.CredentialsSupplied = cloneBool(facts.CredentialsSupplied)
-	facts.EndpointReachable = cloneBool(facts.EndpointReachable)
-	facts.CredentialsAccepted = cloneBool(facts.CredentialsAccepted)
-	facts.ResponseReceived = cloneBool(facts.ResponseReceived)
-	facts.GenerationCompleted = cloneBool(facts.GenerationCompleted)
-	facts.TextReturned = cloneBool(facts.TextReturned)
-	facts.ExpectedTextMatched = cloneBool(facts.ExpectedTextMatched)
-	facts.StructuredOutputRequested = cloneBool(facts.StructuredOutputRequested)
-	facts.ValidJSON = cloneBool(facts.ValidJSON)
-	facts.SchemaMatched = cloneBool(facts.SchemaMatched)
-	return facts
-}
-
-func cloneSmokeTestTiming(timing SmokeTestTiming) SmokeTestTiming {
-	timing.CapacityWait = cloneDuration(timing.CapacityWait)
-	timing.RequestDuration = cloneDuration(timing.RequestDuration)
-	timing.RetryDelay = cloneDuration(timing.RetryDelay)
-	timing.EvaluationDuration = cloneDuration(timing.EvaluationDuration)
-	return timing
-}
-
-func cloneBool(value *bool) *bool {
-	if value == nil {
-		return nil
-	}
-	cloned := *value
-	return &cloned
-}
-
-func cloneDuration(value *time.Duration) *time.Duration {
-	if value == nil {
-		return nil
-	}
-	cloned := *value
-	return &cloned
-}
-
-func cloneFloat64(value *float64) *float64 {
-	if value == nil {
-		return nil
-	}
-	cloned := *value
-	return &cloned
-}
-
-func cloneInt(value *int) *int {
-	if value == nil {
-		return nil
-	}
-	cloned := *value
-	return &cloned
-}
-
 func cloneString(value *string) *string {
 	if value == nil {
 		return nil

internal/domain/smoke_diagnostics_test.go

@@ -1,9 +1,6 @@
 package domain
 
-import (
+import "testing"
-	"testing"
-	"time"
-)
 
 func TestCloneBackendCopiesDiagnosticMetadataAndProviderValues(t *testing.T) {
 	profile := "profile"
@@ -22,10 +19,7 @@ func TestCloneBackendCopiesDiagnosticMetadataAndProviderValues(t *testing.T) {
 		},
 	}
 
-	cloned, err := CloneBackend(backend)
+	cloned := CloneBackend(backend)
-	if err != nil {
-		t.Fatal(err)
-	}
 	*cloned.SmokeTests.DefaultProfile = "changed"
 	*cloned.SmokeTests.Reachability.Endpoint = "changed"
 	*cloned.SmokeTests.Authentication.Kind = "changed"
@@ -41,72 +35,12 @@ func TestCloneBackendCopiesDiagnosticMetadataAndProviderValues(t *testing.T) {
 	}
 }
 
-func TestCloneSmokeTestRequestOwnsOptionalSettings(t *testing.T) {
+func TestCloneBackendPreservesProviderMapPresence(t *testing.T) {
-	temperature := 0.25
+	if cloned := CloneBackend(Backend{}); cloned.ExtraParams != nil {
-	retries := 2
+		t.Fatalf("nil provider map became %#v", cloned.ExtraParams)
-	reasoning := "low"
-	request := SmokeTestRequest{
-		APIKey:           "secret",
-		TransientRetries: &retries,
-		Execution: &ExecutionTargetOverride{
-			Temperature:     &temperature,
-			ReasoningEffort: &reasoning,
-			ExtraParams:     map[string]any{"nested": map[string]any{"value": "original"}},
-		},
 	}
-
+	cloned := CloneBackend(Backend{ExtraParams: map[string]any{"empty": map[string]any{}, "null": nil}})
-	cloned, err := CloneSmokeTestRequest(request)
+	if cloned.ExtraParams == nil || cloned.ExtraParams["empty"].(map[string]any) == nil || cloned.ExtraParams["null"] != nil {
-	if err != nil {
+		t.Fatalf("provider map presence changed: %#v", cloned.ExtraParams)
-		t.Fatal(err)
-	}
-	*cloned.TransientRetries = 3
-	*cloned.Execution.Temperature = 0.5
-	*cloned.Execution.ReasoningEffort = "high"
-	cloned.Execution.ExtraParams["nested"].(map[string]any)["value"] = "changed"
-
-	if retries != 2 || temperature != 0.25 || reasoning != "low" {
-		t.Fatal("cloned request shared optional scalar pointers")
-	}
-	if got := request.Execution.ExtraParams["nested"].(map[string]any)["value"]; got != "original" {
-		t.Fatalf("source provider parameter changed through clone: %v", got)
-	}
-}
-
-func TestCloneSmokeTestReportOwnsMutableValues(t *testing.T) {
-	applicable := true
-	reachable := true
-	status := 200
-	wait := 3 * time.Millisecond
-	report := SmokeTestReport{
-		Applicable: &applicable,
-		Target: SmokeTestTarget{
-			EffectiveSettings: ExecutionTarget{
-				ExtraParams: map[string]any{"nested": map[string]any{"value": "original"}},
-			},
-		},
-		Facts: SmokeTestFacts{EndpointReachable: &reachable},
-		Attempts: []SmokeTestAttempt{{
-			HTTPStatus: &status,
-			Facts:      SmokeTestFacts{EndpointReachable: &reachable},
-			Timing:     SmokeTestTiming{CapacityWait: &wait},
-		}},
-	}
-
-	cloned, err := CloneSmokeTestReport(report)
-	if err != nil {
-		t.Fatal(err)
-	}
-	*cloned.Applicable = false
-	*cloned.Facts.EndpointReachable = false
-	*cloned.Attempts[0].HTTPStatus = 503
-	*cloned.Attempts[0].Facts.EndpointReachable = false
-	*cloned.Attempts[0].Timing.CapacityWait = time.Second
-	cloned.Target.EffectiveSettings.ExtraParams["nested"].(map[string]any)["value"] = "changed"
-
-	if !applicable || !reachable || status != 200 || wait != 3*time.Millisecond {
-		t.Fatal("cloned report shared optional scalar pointers")
-	}
-	if got := report.Target.EffectiveSettings.ExtraParams["nested"].(map[string]any)["value"]; got != "original" {
-		t.Fatalf("source provider parameter changed through clone: %v", got)
 	}
 }

internal/engine/engine.go

@@ -41,13 +41,17 @@ type ConfigurationSources struct {
 
 // Options collects construction choices from the public facade.
 type Options struct {
-	llmClient       llm.Client
+	llmClient                llm.Client
-	artifactReader  artifact.Reader
+	artifactReader           artifact.Reader
-	validator       validate.Validator
+	validator                validate.ValidationPreparer
-	validatorSource bool
+	validatorSource          bool
-	artifactSource  bool
+	artifactSource           bool
+	disableBundledOpenRouter bool
 }
 
+// SetBundledOpenRouter selects whether the built-in OpenRouter source is installed.
+func (o *Options) SetBundledOpenRouter(enabled bool) { o.disableBundledOpenRouter = !enabled }
+
 // SetLLMClient selects the client collaborator for one engine.
 func (o *Options) SetLLMClient(client llm.Client) { o.llmClient = client }
 
@@ -69,7 +73,7 @@ func (o *Options) SetSchemaFS(fsys fs.FS, root string) error {
 
 // SetSchemaFile selects a single schema file.
 func (o *Options) SetSchemaFile(path string) error {
-	fsys, root, _, err := fileSource(path)
+	fsys, root, err := fileSource(path)
 	if err != nil {
 		return err
 	}
@@ -94,9 +98,9 @@ type resourceNamespaces struct {
 }
 
 type identityInventory interface {
-	ListBackends(context.Context) ([]string, error)
+	ListBackends(context.Context, configuration.IdentityFilter) ([]string, error)
-	ListProfiles(context.Context) ([]string, error)
+	ListProfiles(context.Context, configuration.IdentityFilter) ([]string, error)
-	ListPrompts(context.Context) ([]domain.PromptIdentity, error)
+	ListPrompts(context.Context, configuration.IdentityFilter) ([]domain.PromptIdentity, error)
 	ListNamespaces(context.Context, []string) ([]string, error)
 	ListCollections(context.Context) ([]configuration.CollectionIdentity, error)
 }
@@ -124,6 +128,11 @@ func New(cfg Config, options Options) (*Engine, error) {
 		return nil, err
 	}
 	underlays := cfg.Sources.Underlays
+	if !options.disableBundledOpenRouter {
+		underlays = make([]configkit.Underlay, 1, len(cfg.Sources.Underlays)+1)
+		underlays[0] = configuration.BundledOpenRouterUnderlay()
+		underlays = append(underlays, cfg.Sources.Underlays...)
+	}
 	main := configkit.Input{Source: configkit.NoSource()}
 	if cfg.Sources.Main != nil {
 		main = *cfg.Sources.Main
@@ -148,10 +157,7 @@ func New(cfg Config, options Options) (*Engine, error) {
 	var client llm.Client
 	var diagnosticHTTPClient *llm.OpenAICompatibleClient
 	if options.llmClient == nil {
-		builtIn, newErr := llm.NewOpenAICompatibleClient(llm.OpenAICompatibleConfig{Timeout: cfg.Timeout, HTTPClient: cfg.HTTPClient})
+		builtIn := llm.NewOpenAICompatibleClient(llm.OpenAICompatibleConfig{Timeout: cfg.Timeout, HTTPClient: cfg.HTTPClient})
-		if newErr != nil {
-			return nil, newErr
-		}
 		diagnosticHTTPClient = builtIn
 		client = generation.NewBuiltIn(manager, builtIn)
 	} else {
@@ -199,23 +205,23 @@ func validateSourceFS(fsys fs.FS, root string) error {
 	return nil
 }
 
-func fileSource(name string) (fs.FS, string, string, error) {
+func fileSource(name string) (fs.FS, string, error) {
 	if strings.TrimSpace(name) == "" {
-		return nil, "", "", fmt.Errorf("source path is required")
+		return nil, "", fmt.Errorf("source path is required")
 	}
 	directory := filepath.Dir(name)
 	base := filepath.Base(name)
 	if base == "." || base == string(filepath.Separator) {
-		return nil, "", "", fmt.Errorf("source path must name a file")
+		return nil, "", fmt.Errorf("source path must name a file")
 	}
 	info, err := os.Stat(name)
 	if err != nil {
-		return nil, "", "", fmt.Errorf("failed to access source file %q: %w", name, err)
+		return nil, "", fmt.Errorf("failed to access source file %q: %w", name, err)
 	}
 	if info.IsDir() {
-		return nil, "", "", fmt.Errorf("source path %q must be a file", name)
+		return nil, "", fmt.Errorf("source path %q must be a file", name)
 	}
-	return os.DirFS(directory), filepath.ToSlash(base), directory, nil
+	return os.DirFS(directory), filepath.ToSlash(base), nil
 }
 
 func (e *Engine) InspectPrompt(ctx context.Context, id string) (*domain.PromptInspection, error) {
@@ -259,24 +265,11 @@ func (e *Engine) ListProfiles(ctx context.Context, filters ...ListingFilter) ([]
 }
 
 func (e *Engine) ListPrompts(ctx context.Context, filters ...ListingFilter) ([]domain.PromptIdentity, error) {
-	mode, namespace, err := resolveListingFilter(filters, e.namespaces.prompt)
+	filter, err := inventoryFilter(filters, e.namespaces.prompt)
 	if err != nil {
 		return nil, err
 	}
-	prompts, err := e.listing.ListPrompts(ctx)
+	return e.listing.ListPrompts(ctx, filter)
-	if err != nil {
-		return nil, err
-	}
-	var filtered []domain.PromptIdentity
-	for _, prompt := range prompts {
-		if matchesListingNamespace(prompt.ID, mode, namespace) {
-			filtered = append(filtered, prompt)
-		}
-	}
-	if err := ctx.Err(); err != nil {
-		return nil, err
-	}
-	return filtered, nil
 }
 
 func (e *Engine) ListNamespaces(ctx context.Context, kinds []string) ([]string, error) {
@@ -298,26 +291,21 @@ func filterIdentityList(
 	ctx context.Context,
 	filters []ListingFilter,
 	scope string,
-	list func(context.Context) ([]string, error),
+	list func(context.Context, configuration.IdentityFilter) ([]string, error),
 ) ([]string, error) {
+	filter, err := inventoryFilter(filters, scope)
+	if err != nil {
+		return nil, err
+	}
+	return list(ctx, filter)
+}
+
+func inventoryFilter(filters []ListingFilter, scope string) (configuration.IdentityFilter, error) {
 	mode, namespace, err := resolveListingFilter(filters, scope)
 	if err != nil {
-		return nil, err
+		return configuration.IdentityFilter{}, err
 	}
-	ids, err := list(ctx)
+	return configuration.IdentityFilter{All: mode == ListingAll, Namespace: namespace}, nil
-	if err != nil {
-		return nil, err
-	}
-	var filtered []string
-	for _, id := range ids {
-		if matchesListingNamespace(id, mode, namespace) {
-			filtered = append(filtered, id)
-		}
-	}
-	if err := ctx.Err(); err != nil {
-		return nil, err
-	}
-	return filtered, nil
 }
 
 func resolveListingFilter(filters []ListingFilter, scope string) (ListingFilterMode, string, error) {
@@ -346,19 +334,6 @@ func resolveListingFilter(filters []ListingFilter, scope string) (ListingFilterM
 	}
 }
 
-func matchesListingNamespace(id string, mode ListingFilterMode, namespace string) bool {
-	switch mode {
-	case ListingNamed:
-		idNamespace, _, qualified := strings.Cut(id, "/")
-		return qualified && idNamespace == namespace
-	case ListingUnqualified:
-		return !strings.Contains(id, "/")
-	case ListingAll:
-		return true
-	default:
-		return false
-	}
-}
 func (e *Engine) Prepare(ctx context.Context, request domain.RunRequest) (*domain.PreparedRun, error) {
 	request, err := e.qualifyRunRequest(request)
 	if err != nil {

internal/filecatalog/catalog.go

@@ -67,15 +67,6 @@ func FindFSYAMLFiles(ctx context.Context, fsys fs.FS, root string) ([]string, er
 	return files, err
 }
 
-// RelativePath computes a clean relative path from root to path.
-func RelativePath(root string, filePath string) string {
-	rel, err := filepath.Rel(root, filePath)
-	if err != nil {
-		return filepath.Clean(filePath)
-	}
-	return filepath.Clean(rel)
-}
-
 // CleanFSRoot normalizes a root path for use with fs.FS while preserving
 // nonblank leading and trailing whitespace.
 func CleanFSRoot(root string) string {

internal/filecatalog/catalog_test.go

@@ -81,16 +81,6 @@ func TestFindFSYAMLFilesHonorsContextCancellation(t *testing.T) {
 	}
 }
 
-func TestRelativePathNested(t *testing.T) {
-	root := t.TempDir()
-	path := filepath.Join(root, "nested", "profiles", "local.yaml")
-	got := RelativePath(root, path)
-	want := filepath.Join("nested", "profiles", "local.yaml")
-	if got != want {
-		t.Fatalf("expected relative path %q, got %q", want, got)
-	}
-}
-
 func TestCleanFSRoot(t *testing.T) {
 	tests := []struct {
 		name string

internal/generation/coordinator.go

@@ -85,6 +85,12 @@ func (c *Coordinator) GenerateWithEvidence(
 	return c.generate(ctx, req, true)
 }
 
+// PreparationError identifies a built-in request preparation failure.
+type PreparationError struct{ Cause error }
+
+func (e *PreparationError) Error() string { return e.Cause.Error() }
+func (e *PreparationError) Unwrap() error { return e.Cause }
+
 func (c *Coordinator) generate(
 	ctx context.Context,
 	req domain.GenerateRequest,
@@ -95,7 +101,7 @@ func (c *Coordinator) generate(
 	}
 	prepared, err := c.builtIn.PrepareGeneration(req)
 	if err != nil {
-		return nil, err, GenerationEvidence{}
+		return nil, &PreparationError{Cause: err}, GenerationEvidence{PreparationFailed: true}
 	}
 
 	evidence := GenerationEvidence{}
@@ -120,66 +126,37 @@ func (c *Coordinator) generate(
 			return finish(nil, err)
 		}
 		ordinal := attempts + 1
-		outcome, dispatched, capacityWait, generationDuration, startedAt := c.execute(ctx, req.Target.BackendID, prepared, captureEvidence)
+		result := c.execute(ctx, req.Target.BackendID, prepared, captureEvidence)
-		if dispatched {
+		if result.Dispatched {
 			attempts++
 		}
-		if captureEvidence {
+		recordAttempt(result, false, captureEvidence, &evidence, &usage, recorder, generation, ordinal)
-			attempt := AttemptEvidence{
+		if result.Outcome.Err == nil {
-				StartedAt:           startedAt.UTC(),
-				Dispatched:          dispatched,
-				ResponseReceived:    outcome.Evidence.ResponseReceived,
-				HTTP:                cloneHTTPEvidence(outcome.Evidence),
-				CapacityWait:        capacityWait,
-				RequestDuration:     generationDuration,
-				Failure:             ClassifyFailure(outcome.Err),
-				ResponseDecoded:     outcome.ResponseDecoded,
-				GenerationCompleted: outcome.GenerationCompleted,
-			}
-			if outcome.StructuredOutputRequested != nil {
-				requested := *outcome.StructuredOutputRequested
-				attempt.StructuredOutputRequested = &requested
-			}
-			if dispatched {
-				usage.Add(outcome.Usage, outcome.UsagePresence)
-				var attemptUsage observation.UsageAccumulator
-				attemptUsage.Add(outcome.Usage, outcome.UsagePresence)
-				attempt.Usage = attemptUsage.Observed()
-			}
-			evidence.Attempts = append(evidence.Attempts, attempt)
-		}
-		if recorder != nil {
-			recorder.Attempt(observation.AttemptData{Generation: generation, Attempt: ordinal,
-				Dispatched: dispatched, CapacityWait: capacityWait, GenerationDuration: generationDuration,
-				Outcome: attemptOutcome(outcome.Err), Failure: ClassifyFailure(outcome.Err),
-				StatusCode: outcome.StatusCode, Usage: outcome.Usage, UsagePresence: outcome.UsagePresence})
-		}
-		if outcome.Err == nil {
 			if err := ctx.Err(); err != nil {
 				if captureEvidence {
-					return finish(outcome.Response, err)
+					return finish(result.Outcome.Response, err)
 				}
 				return finish(nil, err)
 			}
-			return finish(outcome.Response, nil)
+			return finish(result.Outcome.Response, nil)
 		}
-		if !dispatched || !eligibleStatus(outcome) {
+		if !result.Dispatched || !eligibleStatus(result.Outcome) {
 			if captureEvidence {
-				return finish(outcome.Response, outcome.Err)
+				return finish(result.Outcome.Response, result.Outcome.Err)
 			}
-			return finish(nil, outcome.Err)
+			return finish(nil, result.Outcome.Err)
 		}
 		if retriesUsed == req.TransientRetries {
 			if retriesUsed == 0 {
-				return finish(nil, outcome.Err)
+				return finish(nil, result.Outcome.Err)
 			}
-			return finish(nil, &ExhaustedError{attempts: attempts, cause: outcome.Err})
+			return finish(nil, &ExhaustedError{attempts: attempts, cause: result.Outcome.Err})
 		}
 		if err := ctx.Err(); err != nil {
 			return finish(nil, err)
 		}
 		retryOrdinal := retriesUsed + 1
-		delay := retryDelay(c.backoff(retryOrdinal), outcome.RetryNotBefore, c.now())
+		delay := retryDelay(c.backoff(retryOrdinal), result.Outcome.RetryNotBefore, c.now())
 		waitStart := c.now()
 		waitErr := c.wait(ctx, delay)
 		waitDuration := elapsed(waitStart, c.now())
@@ -200,127 +177,133 @@ func (c *Coordinator) generate(
 	}
 }
 
-func (c *Coordinator) generateInjected(
+func (c *Coordinator) generateInjected(ctx context.Context, req domain.GenerateRequest, captureEvidence bool) (*domain.GenerateResponse, error, GenerationEvidence) {
-	ctx context.Context,
-	req domain.GenerateRequest,
-	captureEvidence bool,
-) (*domain.GenerateResponse, error, GenerationEvidence) {
 	evidence := GenerationEvidence{}
 	var usage observation.UsageAccumulator
-	finish := func(response *domain.GenerateResponse, err error) (*domain.GenerateResponse, error, GenerationEvidence) {
-		if captureEvidence {
-			evidence.Usage = usage.Observed()
-		}
-		return response, err, evidence
-	}
-	recorder := observation.FromContext(ctx)
 	generation := req.Generation
 	if generation == 0 {
 		generation = 1
 	}
-	start := c.now()
+	result := c.executeInjected(ctx, req)
-	release, err := c.manager.Acquire(ctx, req.Target.BackendID)
+	recordAttempt(result, true, captureEvidence, &evidence, &usage, observation.FromContext(ctx), generation, 1)
-	capacityWait := c.capacityWait(req.Target.BackendID, start)
-	if err != nil {
-		if captureEvidence {
-			evidence.Attempts = append(evidence.Attempts, AttemptEvidence{
-				StartedAt:    start.UTC(),
-				CapacityWait: capacityWait,
-				Failure:      ClassifyFailure(err),
-			})
-		}
-		if recorder != nil {
-			recorder.Attempt(observation.AttemptData{Generation: generation, Attempt: 1, CapacityWait: capacityWait, Outcome: domain.ExecutionOutcomeError, Failure: ClassifyFailure(err)})
-		}
-		return finish(nil, err)
-	}
-	defer release()
-	if err := ctx.Err(); err != nil {
-		release()
-		if captureEvidence {
-			evidence.Attempts = append(evidence.Attempts, AttemptEvidence{
-				StartedAt:    start.UTC(),
-				CapacityWait: capacityWait,
-				Failure:      ClassifyFailure(err),
-			})
-		}
-		if recorder != nil {
-			recorder.Attempt(observation.AttemptData{Generation: generation, Attempt: 1, CapacityWait: capacityWait, Outcome: domain.ExecutionOutcomeError, Failure: ClassifyFailure(err)})
-		}
-		return finish(nil, err)
-	}
-	dispatchStart := c.now()
-	response, err := c.injected.Generate(ctx, req)
-	duration := elapsed(dispatchStart, c.now())
-	if err == nil && response == nil {
-		err = llm.ErrMalformedResponse
-	}
 	if captureEvidence {
-		attempt := AttemptEvidence{
+		evidence.Usage = usage.Observed()
-			StartedAt:           start.UTC(),
-			Dispatched:          true,
-			ResponseReceived:    response != nil,
-			RequestDuration:     duration,
-			Failure:             ClassifyFailure(err),
-			GenerationCompleted: err == nil && response != nil,
-		}
-		requested := req.StructuredOutput != nil
-		attempt.StructuredOutputRequested = &requested
-		var reportedUsage domain.TokenUsage
-		var reportedPresence *domain.TokenUsagePresence
-		if err == nil && response != nil {
-			reportedUsage = response.Usage
-			reportedPresence = response.UsagePresence
-		}
-		usage.Add(reportedUsage, reportedPresence)
-		var attemptUsage observation.UsageAccumulator
-		attemptUsage.Add(reportedUsage, reportedPresence)
-		attempt.Usage = attemptUsage.Observed()
-		evidence.Attempts = append(evidence.Attempts, attempt)
 	}
-	release()
+	if result.Outcome.Err != nil {
-	if recorder != nil {
+		return nil, result.Outcome.Err, evidence
-		data := observation.AttemptData{Generation: generation, Attempt: 1, Dispatched: true, CapacityWait: capacityWait, GenerationDuration: duration,
-			Outcome: attemptOutcome(err), Failure: ClassifyFailure(err)}
-		if err == nil {
-			data.Usage = response.Usage
-			data.UsagePresence = response.UsagePresence
-		}
-		recorder.Attempt(data)
-	}
-	if err != nil {
-		return finish(nil, err)
 	}
 	if err := ctx.Err(); err != nil {
 		if captureEvidence {
-			return finish(response, err)
+			return result.Outcome.Response, err, evidence
 		}
-		return finish(nil, err)
+		return nil, err, evidence
 	}
-	return finish(response, nil)
+	return result.Outcome.Response, nil, evidence
 }
 
-func (c *Coordinator) execute(ctx context.Context, backendID string, prepared *llm.PreparedGeneration, captureEvidence bool) (outcome llm.AttemptOutcome, dispatched bool, capacityWait, generationDuration time.Duration, startedAt time.Time) {
+func (c *Coordinator) executeInjected(ctx context.Context, req domain.GenerateRequest) attemptResult {
-	start := c.now()
+	result := attemptResult{StartedAt: c.now()}
-	startedAt = start
+	release, err := c.manager.Acquire(ctx, req.Target.BackendID)
-	release, err := c.manager.Acquire(ctx, backendID)
+	result.CapacityWait = c.capacityWait(req.Target.BackendID, result.StartedAt)
-	capacityWait = c.capacityWait(backendID, start)
 	if err != nil {
-		return llm.AttemptOutcome{Err: err}, false, capacityWait, 0, startedAt
+		result.Outcome.Err = err
+		return result
 	}
 	defer release()
 	if err := ctx.Err(); err != nil {
-		return llm.AttemptOutcome{Err: err}, false, capacityWait, 0, startedAt
+		result.Outcome.Err = err
+		return result
+	}
+	start := c.now()
+	result.Dispatched = true
+	requested := req.StructuredOutput != nil
+	result.Outcome.StructuredOutputRequested = &requested
+	result.Outcome.Response, result.Outcome.Err = c.injected.Generate(ctx, req)
+	result.RequestDuration = elapsed(start, c.now())
+	if result.Outcome.Err == nil && result.Outcome.Response == nil {
+		result.Outcome.Err = llm.ErrMalformedResponse
+	}
+	if result.Outcome.Err == nil {
+		result.Outcome.Usage = result.Outcome.Response.Usage
+		result.Outcome.UsagePresence = result.Outcome.Response.UsagePresence
+	}
+	return result
+}
+
+type attemptResult struct {
+	Outcome         llm.AttemptOutcome
+	Dispatched      bool
+	CapacityWait    time.Duration
+	RequestDuration time.Duration
+	StartedAt       time.Time
+}
+
+// recordAttempt runs after the attempt has released its permit, including when
+// the recorder calls application code. Injected clients expose no HTTP facts.
+func recordAttempt(result attemptResult, injected, capture bool, evidence *GenerationEvidence, usage *observation.UsageAccumulator, recorder *observation.Recorder, generation, ordinal uint64) {
+	outcome := result.Outcome
+	failure := ClassifyFailure(outcome.Err)
+	if capture {
+		attempt := AttemptEvidence{
+			StartedAt: result.StartedAt.UTC(), Dispatched: result.Dispatched,
+			CapacityWait: result.CapacityWait, RequestDuration: result.RequestDuration,
+			Failure: failure,
+		}
+		if injected {
+			attempt.ResponseReceived = outcome.Response != nil
+			attempt.GenerationCompleted = outcome.Err == nil && outcome.Response != nil
+			if result.Dispatched {
+				attempt.CapacityWait = 0
+			}
+		} else {
+			attempt.ResponseReceived = outcome.Evidence.ResponseReceived
+			attempt.HTTP = cloneHTTPEvidence(outcome.Evidence)
+			attempt.ResponseDecoded = outcome.ResponseDecoded
+			attempt.GenerationCompleted = outcome.GenerationCompleted
+		}
+		if outcome.StructuredOutputRequested != nil {
+			requested := *outcome.StructuredOutputRequested
+			attempt.StructuredOutputRequested = &requested
+		}
+		if result.Dispatched {
+			usage.Add(outcome.Usage, outcome.UsagePresence)
+			var single observation.UsageAccumulator
+			single.Add(outcome.Usage, outcome.UsagePresence)
+			attempt.Usage = single.Observed()
+		}
+		evidence.Attempts = append(evidence.Attempts, attempt)
+	}
+	if recorder != nil {
+		recorder.Attempt(observation.AttemptData{Generation: generation, Attempt: ordinal,
+			Dispatched: result.Dispatched, CapacityWait: result.CapacityWait, GenerationDuration: result.RequestDuration,
+			Outcome: attemptOutcome(outcome.Err), Failure: failure, StatusCode: outcome.StatusCode,
+			Usage: outcome.Usage, UsagePresence: outcome.UsagePresence})
+	}
+}
+
+func (c *Coordinator) execute(ctx context.Context, backendID string, prepared *llm.PreparedGeneration, captureEvidence bool) attemptResult {
+	result := attemptResult{StartedAt: c.now()}
+	release, err := c.manager.Acquire(ctx, backendID)
+	result.CapacityWait = c.capacityWait(backendID, result.StartedAt)
+	if err != nil {
+		result.Outcome.Err = err
+		return result
+	}
+	defer release()
+	if err := ctx.Err(); err != nil {
+		result.Outcome.Err = err
+		return result
 	}
 	dispatchStart := c.now()
 	if captureEvidence {
-		outcome = prepared.ExecuteWithEvidence(ctx)
+		result.Outcome = prepared.ExecuteWithEvidence(ctx)
-		dispatched = outcome.Evidence.DispatchInvoked
+		result.Dispatched = result.Outcome.Evidence.DispatchInvoked
 	} else {
-		outcome = prepared.Execute(ctx)
+		result.Outcome = prepared.Execute(ctx)
-		dispatched = true
+		result.Dispatched = true
 	}
-	return outcome, dispatched, capacityWait, elapsed(dispatchStart, c.now()), startedAt
+	result.RequestDuration = elapsed(dispatchStart, c.now())
+	return result
 }
 
 func (c *Coordinator) capacityWait(backendID string, start time.Time) time.Duration {

internal/generation/coordinator_test.go

@@ -40,10 +40,7 @@ func testCoordinator(t *testing.T, transport transportFunc) *Coordinator {
 	if err != nil {
 		t.Fatal(err)
 	}
-	client, err := llm.NewOpenAICompatibleClient(llm.OpenAICompatibleConfig{HTTPClient: &http.Client{Transport: transport}})
+	client := llm.NewOpenAICompatibleClient(llm.OpenAICompatibleConfig{HTTPClient: &http.Client{Transport: transport}})
-	if err != nil {
-		t.Fatal(err)
-	}
 	coordinator := NewBuiltIn(manager, client)
 	coordinator.jitter = func(time.Duration) time.Duration { return 0 }
 	coordinator.wait = func(ctx context.Context, _ time.Duration) error { return ctx.Err() }

internal/generation/evidence.go

@@ -10,6 +10,8 @@ import (
 // GenerationEvidence contains invocation-local request evidence without raw
 // provider bodies, headers, credentials, or generated content.
 type GenerationEvidence struct {
+	// PreparationFailed identifies a built-in request rejected before attempts.
+	PreparationFailed bool
 	// InitialEndpoint is the frozen built-in request URL, if prepared.
 	// Injected generation leaves it unknown.
 	InitialEndpoint string

internal/generation/observation_test.go

@@ -144,6 +144,32 @@ func (c fixedClient) Generate(context.Context, domain.GenerateRequest) (*domain.
 	return c.response, c.err
 }
 
+func TestInjectedObserverRunsAfterPermitRelease(t *testing.T) {
+	configured := testCoordinator(t, func(*http.Request) (*http.Response, error) { t.Fatal("unexpected HTTP request"); return nil, nil })
+	coordinator := NewInjected(configured.manager, fixedClient{response: &domain.GenerateResponse{}})
+	called := false
+	recorder, err := observation.New(func(event domain.ExecutionEvent) {
+		if event.Kind != domain.ExecutionAttempt {
+			return
+		}
+		called = true
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+		defer cancel()
+		release, err := coordinator.manager.Acquire(ctx, "limited")
+		if err != nil {
+			t.Errorf("observer could not acquire permit: %v", err)
+			return
+		}
+		release()
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := coordinator.Generate(observation.WithRecorder(context.Background(), recorder), testRequest(0)); err != nil || !called {
+		t.Fatalf("generation error = %v, observer called = %v", err, called)
+	}
+}
+
 func TestObservedInjectedUsageAndRepairGeneration(t *testing.T) {
 	manager, err := capacity.NewManager(nil)
 	if err != nil {

internal/jsonvalue/trusted.go

@@ -0,0 +1,97 @@
+package jsonvalue
+
+import "reflect"
+
+func cloneTrustedMap(src map[string]any) map[string]any {
+	if src == nil {
+		return nil
+	}
+	out := make(map[string]any, len(src))
+	for k, v := range src {
+		out[k] = CloneTrusted(v)
+	}
+	return out
+}
+
+// CloneTrusted detaches a previously accepted value without revalidating it.
+func CloneTrusted(value any) any {
+	if value == nil {
+		return nil
+	}
+	switch v := value.(type) {
+	case map[string]any:
+		return cloneTrustedMap(v)
+	case []any:
+		out := make([]any, len(v))
+		for i, item := range v {
+			out[i] = CloneTrusted(item)
+		}
+		return out
+	case []string:
+		if v == nil {
+			return []string(nil)
+		}
+		return append([]string{}, v...)
+	case []byte:
+		if v == nil {
+			return []byte(nil)
+		}
+		return append([]byte{}, v...)
+	default:
+		return cloneTrustedReflect(reflect.ValueOf(value)).Interface()
+	}
+}
+
+func cloneTrustedReflect(value reflect.Value) reflect.Value {
+	if !value.IsValid() {
+		return value
+	}
+
+	switch value.Kind() {
+	case reflect.Interface:
+		if value.IsNil() {
+			return reflect.Zero(value.Type())
+		}
+		copied := cloneTrustedReflect(value.Elem())
+		if copied.IsValid() && copied.Type().AssignableTo(value.Type()) {
+			return copied
+		}
+		out := reflect.New(value.Type()).Elem()
+		out.Set(copied)
+		return out
+	case reflect.Pointer:
+		if value.IsNil() {
+			return reflect.Zero(value.Type())
+		}
+		out := reflect.New(value.Type().Elem())
+		out.Elem().Set(cloneTrustedReflect(value.Elem()))
+		return out
+	case reflect.Map:
+		if value.IsNil() {
+			return reflect.Zero(value.Type())
+		}
+		out := reflect.MakeMapWithSize(value.Type(), value.Len())
+		iter := value.MapRange()
+		for iter.Next() {
+			out.SetMapIndex(cloneTrustedReflect(iter.Key()), cloneTrustedReflect(iter.Value()))
+		}
+		return out
+	case reflect.Slice:
+		if value.IsNil() {
+			return reflect.Zero(value.Type())
+		}
+		out := reflect.MakeSlice(value.Type(), value.Len(), value.Cap())
+		for i := 0; i < value.Len(); i++ {
+			out.Index(i).Set(cloneTrustedReflect(value.Index(i)))
+		}
+		return out
+	case reflect.Array:
+		out := reflect.New(value.Type()).Elem()
+		for i := 0; i < value.Len(); i++ {
+			out.Index(i).Set(cloneTrustedReflect(value.Index(i)))
+		}
+		return out
+	default:
+		return value
+	}
+}

internal/jsonvalue/trusted_test.go

@@ -0,0 +1,27 @@
+package jsonvalue
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+)
+
+type trustedNamed string
+
+func TestCloneTrustedPreservesTypesAndDetaches(t *testing.T) {
+	named := trustedNamed("value")
+	original := map[string]any{"": map[string]any{"number": json.Number("9007199254740993")}, "typed": []string{"original"}, "pointer": &named, "nilmap": map[string]any(nil), "nilslice": []string(nil), "empty": []any{}}
+	copy := CloneTrusted(original).(map[string]any)
+	if !reflect.DeepEqual(copy, original) {
+		t.Fatalf("clone = %#v", copy)
+	}
+	copy[""].(map[string]any)["number"] = json.Number("1")
+	copy["typed"].([]string)[0] = "changed"
+	*copy["pointer"].(*trustedNamed) = "changed"
+	if original[""].(map[string]any)["number"] != json.Number("9007199254740993") || original["typed"].([]string)[0] != "original" || named != "value" {
+		t.Fatal("clone shares mutable storage")
+	}
+	if copy["nilmap"].(map[string]any) != nil || copy["nilslice"].([]string) != nil || copy["empty"].([]any) == nil {
+		t.Fatal("nil/empty shape changed")
+	}
+}

internal/llm/http_evidence_test.go

@@ -25,10 +25,7 @@ func TestGetWithEvidenceCapturesResponseAndOmitsURLUserInfo(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{Timeout: time.Second})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{Timeout: time.Second})
-	if err != nil {
-		t.Fatalf("construct client: %v", err)
-	}
 	endpoint := strings.Replace(server.URL, "http://", "http://user:secret@", 1) + "/health"
 	response, evidence, err := client.GetWithEvidence(context.Background(), endpoint, 0)
 	if err != nil {
@@ -88,7 +85,7 @@ func TestGetWithAuthenticationEvidenceResolvesOptionalCredentials(t *testing.T)
 		t.Run(tc.name, func(t *testing.T) {
 			t.Setenv("PROMPTKIT_DIAGNOSTIC_KEY", tc.environment)
 			var authorization string
-			client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
 				HTTPClient: &http.Client{Transport: roundTripFunc(func(request *http.Request) (*http.Response, error) {
 					authorization = request.Header.Get("Authorization")
 					return &http.Response{
@@ -98,9 +95,6 @@ func TestGetWithAuthenticationEvidenceResolvesOptionalCredentials(t *testing.T)
 					}, nil
 				})},
 			})
-			if err != nil {
-				t.Fatal(err)
-			}
 
 			response, evidence, err := client.GetWithAuthenticationEvidence(
 				context.Background(), "https://example.invalid/key", 0, tc.target,
@@ -269,10 +263,7 @@ func TestGetWithEvidencePreservesClientAndIsolatesConcurrentCalls(t *testing.T)
 
 	transport := http.DefaultTransport
 	supplied := &http.Client{Transport: transport, Timeout: 7 * time.Second, CheckRedirect: redirect, Jar: jar}
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{HTTPClient: supplied})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{HTTPClient: supplied})
-	if err != nil {
-		t.Fatalf("construct client: %v", err)
-	}
 
 	const calls = 8
 	evidences := make([]HTTPExecutionEvidence, calls)
@@ -307,15 +298,12 @@ func TestGetWithEvidencePreservesClientAndIsolatesConcurrentCalls(t *testing.T)
 }
 
 func TestGetWithEvidenceAppliesTargetTimeout(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{Timeout: 5 * time.Second, HTTPClient: &http.Client{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{Timeout: 5 * time.Second, HTTPClient: &http.Client{
 		Transport: roundTripFunc(func(request *http.Request) (*http.Response, error) {
 			<-request.Context().Done()
 			return nil, request.Context().Err()
 		}),
 	}})
-	if err != nil {
-		t.Fatalf("construct client: %v", err)
-	}
 
 	response, evidence, err := client.GetWithEvidence(context.Background(), "https://diagnostic.example/slow", 1)
 	if response != nil || !errors.Is(err, context.DeadlineExceeded) {

internal/llm/openai_compatible_client.go

@@ -17,10 +17,10 @@ import (
 
 	"go.maximumdirect.net/promptkit/internal/defaults"
 	"go.maximumdirect.net/promptkit/internal/domain"
+	"go.maximumdirect.net/promptkit/internal/jsonvalue"
 )
 
 var (
-	ErrInvalidConfig     = errors.New("invalid llm client configuration")
 	ErrInvalidRequest    = errors.New("invalid generate request")
 	ErrRequestFailed     = errors.New("llm request failed")
 	ErrTransport         = errors.New("llm transport failed")
@@ -43,28 +43,15 @@ func (e *requestFailedError) Unwrap() []error {
 }
 
 type OpenAICompatibleConfig struct {
-	BaseURL    string
-	Model      string
 	Timeout    time.Duration
 	HTTPClient *http.Client
 }
 
 type OpenAICompatibleClient struct {
-	baseURL      string
+	httpClient *http.Client
-	defaultModel string
-	httpClient   *http.Client
 }
 
-func NewOpenAICompatibleClient(cfg OpenAICompatibleConfig) (*OpenAICompatibleClient, error) {
+func NewOpenAICompatibleClient(cfg OpenAICompatibleConfig) *OpenAICompatibleClient {
-	baseURL := ""
-	if strings.TrimSpace(cfg.BaseURL) != "" {
-		var err error
-		baseURL, err = domain.NormalizeOpenAICompatibleBaseEndpoint(cfg.BaseURL)
-		if err != nil {
-			return nil, fmt.Errorf("%w: invalid base URL: %v", ErrInvalidConfig, err)
-		}
-	}
-
 	timeout := cfg.Timeout
 	if timeout <= 0 {
 		timeout = defaults.LLMRequestTimeoutDefault
@@ -82,10 +69,8 @@ func NewOpenAICompatibleClient(cfg OpenAICompatibleConfig) (*OpenAICompatibleCli
 	}
 
 	return &OpenAICompatibleClient{
-		baseURL:      baseURL,
+		httpClient: client,
-		defaultModel: cfg.Model,
+	}
-		httpClient:   client,
-	}, nil
 }
 
 func (c *OpenAICompatibleClient) Generate(ctx context.Context, req domain.GenerateRequest) (*domain.GenerateResponse, error) {
@@ -132,11 +117,7 @@ func (c *OpenAICompatibleClient) PrepareGeneration(req domain.GenerateRequest) (
 		return nil, fmt.Errorf("%w: %v", ErrInvalidRequest, err)
 	}
 
-	selectedEndpoint := req.Target.Endpoint
+	endpoint, err := domain.NormalizeOpenAICompatibleBaseEndpoint(req.Target.Endpoint)
-	if strings.TrimSpace(selectedEndpoint) == "" {
-		selectedEndpoint = c.baseURL
-	}
-	endpoint, err := domain.NormalizeOpenAICompatibleBaseEndpoint(selectedEndpoint)
 	if err != nil {
 		return nil, fmt.Errorf("%w: invalid endpoint: %v", ErrInvalidRequest, err)
 	}
@@ -145,12 +126,10 @@ func (c *OpenAICompatibleClient) PrepareGeneration(req domain.GenerateRequest) (
 		return nil, fmt.Errorf("%w: invalid endpoint path: %v", ErrInvalidRequest, err)
 	}
 
-	wireReq, err := openAIChatRequestFromGenerateRequest(req, c.defaultModel)
+	// Custom JSON encoders may mutate their receivers. Both payload encoding
-	if err != nil {
+	// and encoding-failure diagnostics must use values detached from metadata.
-		return nil, fmt.Errorf("%w: %v", ErrInvalidRequest, err)
+	req.Target.ExtraParams = jsonvalue.CloneTrusted(req.Target.ExtraParams).(map[string]any)
-	}
+	wirePayload, err := openAIChatRequestPayload(req)
-
-	wirePayload, err := openAIChatRequestPayload(wireReq)
 	if err != nil {
 		return nil, fmt.Errorf("%w: %v", ErrInvalidRequest, err)
 	}
@@ -179,7 +158,7 @@ func (c *OpenAICompatibleClient) PrepareGeneration(req domain.GenerateRequest) (
 	return &PreparedGeneration{
 		endpoint: endpoint, payload: payload, apiKey: apiKey,
 		timeoutSeconds: req.Target.TimeoutSeconds, httpClient: httpClient,
-		structuredOutputRequested: wireReq.ResponseFormat != nil,
+		structuredOutputRequested: wirePayload["response_format"] != nil,
 	}, nil
 }
 
@@ -370,40 +349,69 @@ func tokenCount(value *int) int {
 	return *value
 }
 
+type responseErrorReader struct {
+	reader io.Reader
+	err    error
+}
+
+func (r *responseErrorReader) Read(p []byte) (int, error) {
+	n, err := r.reader.Read(p)
+	if err != nil && !errors.Is(err, io.EOF) {
+		r.err = err
+	}
+	return n, err
+}
+
 func decodeOpenAIChatResponse(body io.Reader) (openAIChatResponse, error) {
+	observed := &responseErrorReader{reader: body}
 	limited := &io.LimitedReader{
-		R: body,
+		R: observed,
 		N: maxOpenAIChatResponseBytes + 1,
 	}
 	decoder := json.NewDecoder(limited)
 
 	var response openAIChatResponse
 	if err := decoder.Decode(&response); err != nil {
-		if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+		if errors.Is(observed.err, context.Canceled) || errors.Is(observed.err, context.DeadlineExceeded) {
-			return openAIChatResponse{}, &requestFailedError{cause: err}
+			return openAIChatResponse{}, &requestFailedError{cause: observed.err}
 		}
 		if limited.N == 0 {
 			return openAIChatResponse{}, openAIChatResponseTooLargeError()
 		}
+		if observed.err != nil {
+			return openAIChatResponse{}, &requestFailedError{cause: observed.err}
+		}
 		return openAIChatResponse{}, fmt.Errorf("%w: failed to decode response", ErrMalformedResponse)
 	}
+	if errors.Is(observed.err, context.Canceled) || errors.Is(observed.err, context.DeadlineExceeded) {
+		return openAIChatResponse{}, &requestFailedError{cause: observed.err}
+	}
 	if limited.N == 0 {
 		return openAIChatResponse{}, openAIChatResponseTooLargeError()
 	}
 
 	var trailing any
 	if err := decoder.Decode(&trailing); !errors.Is(err, io.EOF) {
-		if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+		if errors.Is(observed.err, context.Canceled) || errors.Is(observed.err, context.DeadlineExceeded) {
-			return openAIChatResponse{}, &requestFailedError{cause: err}
+			return openAIChatResponse{}, &requestFailedError{cause: observed.err}
 		}
 		if limited.N == 0 {
 			return openAIChatResponse{}, openAIChatResponseTooLargeError()
 		}
+		if observed.err != nil {
+			return openAIChatResponse{}, &requestFailedError{cause: observed.err}
+		}
 		return openAIChatResponse{}, fmt.Errorf("%w: response contains trailing data", ErrMalformedResponse)
 	}
+	if errors.Is(observed.err, context.Canceled) || errors.Is(observed.err, context.DeadlineExceeded) {
+		return openAIChatResponse{}, &requestFailedError{cause: observed.err}
+	}
 	if limited.N == 0 {
 		return openAIChatResponse{}, openAIChatResponseTooLargeError()
 	}
+	if observed.err != nil {
+		return openAIChatResponse{}, &requestFailedError{cause: observed.err}
+	}
 
 	return response, nil
 }
@@ -416,99 +424,52 @@ func openAIChatResponseTooLargeError() error {
 	)
 }
 
-func openAIChatRequestFromGenerateRequest(req domain.GenerateRequest, defaultModel string) (openAIChatRequest, error) {
+func openAIChatRequestPayload(req domain.GenerateRequest) (map[string]any, error) {
 	model := strings.TrimSpace(req.Target.Model)
 	if model == "" {
-		model = strings.TrimSpace(defaultModel)
+		return nil, errors.New("model is required")
-	}
-	if model == "" {
-		return openAIChatRequest{}, errors.New("model is required")
 	}
 
-	wireReq := openAIChatRequest{
-		Model: model,
-	}
 	sessionID, err := domain.NormalizeSessionID(req.Prompt.SessionID)
 	if err != nil {
-		return openAIChatRequest{}, err
+		return nil, err
 	}
-	wireReq.SessionID = sessionID
 
-	wireReq.Messages = make([]openAIChatRequestMessage, 0, len(req.Prompt.Messages))
+	messages := make([]openAIChatRequestMessage, 0, len(req.Prompt.Messages))
 	for _, msg := range req.Prompt.Messages {
-		wireReq.Messages = append(wireReq.Messages, openAIChatRequestMessageFromRenderedMessage(msg))
+		messages = append(messages, openAIChatRequestMessageFromRenderedMessage(msg))
 	}
 
+	out := map[string]any{"model": model, "messages": messages}
+	if sessionID != "" {
+		out["session_id"] = sessionID
+	}
 	if req.Target.Temperature != 0 || req.TargetPresence.Temperature {
-		wireReq.Temperature = &req.Target.Temperature
+		out["temperature"] = req.Target.Temperature
 	}
 	if req.Target.MaxTokens != 0 || req.TargetPresence.MaxTokens {
-		wireReq.MaxTokens = &req.Target.MaxTokens
+		out["max_tokens"] = req.Target.MaxTokens
 	}
 	if req.Target.TopP != 0 || req.TargetPresence.TopP {
-		wireReq.TopP = &req.Target.TopP
+		out["top_p"] = req.Target.TopP
 	}
 	if strings.TrimSpace(req.Target.ServiceTier) != "" {
-		wireReq.ServiceTier = req.Target.ServiceTier
+		out["service_tier"] = req.Target.ServiceTier
 	}
 	if strings.TrimSpace(req.Target.ReasoningEffort) != "" {
-		wireReq.ReasoningEffort = req.Target.ReasoningEffort
+		out["reasoning_effort"] = req.Target.ReasoningEffort
-	}
-	if len(req.Target.ExtraParams) > 0 {
-		wireReq.ExtraParams = req.Target.ExtraParams
 	}
 	if req.StructuredOutput != nil {
 		responseFormat, err := toOpenAIResponseFormat(req.StructuredOutput)
 		if err != nil {
-			return openAIChatRequest{}, err
+			return nil, err
+		}
+		if responseFormat != nil {
+			out["response_format"] = responseFormat
 		}
-		wireReq.ResponseFormat = responseFormat
 	}
 
-	return wireReq, nil
+	for key, value := range req.Target.ExtraParams {
-}
-
-type openAIChatRequest struct {
-	Model           string                     `json:"model"`
-	SessionID       string                     `json:"session_id,omitempty"`
-	Messages        []openAIChatRequestMessage `json:"messages"`
-	Temperature     *float64                   `json:"temperature,omitempty"`
-	MaxTokens       *int                       `json:"max_tokens,omitempty"`
-	TopP            *float64                   `json:"top_p,omitempty"`
-	ServiceTier     string                     `json:"service_tier,omitempty"`
-	ReasoningEffort string                     `json:"reasoning_effort,omitempty"`
-	ResponseFormat  *openAIResponseFormat      `json:"response_format,omitempty"`
-	ExtraParams     map[string]any             `json:"-"`
-}
-
-func openAIChatRequestPayload(req openAIChatRequest) (map[string]any, error) {
-	out := map[string]any{
-		"model":    req.Model,
-		"messages": req.Messages,
-	}
-	if req.SessionID != "" {
-		out["session_id"] = req.SessionID
-	}
-	if req.Temperature != nil {
-		out["temperature"] = *req.Temperature
-	}
-	if req.MaxTokens != nil {
-		out["max_tokens"] = *req.MaxTokens
-	}
-	if req.TopP != nil {
-		out["top_p"] = *req.TopP
-	}
-	if req.ServiceTier != "" {
-		out["service_tier"] = req.ServiceTier
-	}
-	if req.ReasoningEffort != "" {
-		out["reasoning_effort"] = req.ReasoningEffort
-	}
-	if req.ResponseFormat != nil {
-		out["response_format"] = req.ResponseFormat
-	}
-
-	for key, value := range req.ExtraParams {
 		if key == "" {
 			return nil, errors.New("extra_params key must not be empty")
 		}

internal/llm/openai_compatible_client_test.go

@@ -123,26 +123,19 @@ func (p *recordingProvider) lastRequest(t *testing.T) recordedProviderRequest {
 	return p.requests[len(p.requests)-1]
 }
 
-func newProviderClient(t *testing.T, provider *recordingProvider, config OpenAICompatibleConfig) *OpenAICompatibleClient {
-	t.Helper()
-
-	if config.BaseURL == "" {
-		config.BaseURL = provider.endpoint("/v1")
-	}
-	client, err := NewOpenAICompatibleClient(config)
-	if err != nil {
-		t.Fatalf("construct client: %v", err)
-	}
-	return client
-}
-
 func ordinaryGenerateRequest() domain.GenerateRequest {
 	return domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-		Target: domain.ExecutionTarget{Model: "model"},
+		Target: domain.ExecutionTarget{Endpoint: "https://provider.example/v1", Model: "model"},
 	}
 }
 
+func (p *recordingProvider) generateRequest() domain.GenerateRequest {
+	req := ordinaryGenerateRequest()
+	req.Target.Endpoint = p.endpoint("/v1")
+	return req
+}
+
 type deadlineCapturingTransport struct {
 	deadline    time.Time
 	hasDeadline bool
@@ -253,35 +246,13 @@ func assertDeadlineNear(t *testing.T, deadline, before, after time.Time, duratio
 	}
 }
 
-func TestNewOpenAICompatibleClientRejectsInvalidBaseURL(t *testing.T) {
-	for _, endpoint := range []string{
-		"://invalid",
-		"/v1",
-		"https:///v1",
-		"ftp://provider.example/v1",
-		"https://user@provider.example/v1",
-		"https://provider.example/v1?mode=chat",
-		"https://provider.example/v1#chat",
-	} {
-		t.Run(endpoint, func(t *testing.T) {
-			_, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{BaseURL: endpoint})
-			if !errors.Is(err, ErrInvalidConfig) {
-				t.Fatalf("expected ErrInvalidConfig, got %v", err)
-			}
-		})
-	}
-}
-
 func TestNewOpenAICompatibleClientDoesNotMutateSuppliedZeroTimeoutClient(t *testing.T) {
 	transport := http.DefaultTransport
 	supplied := &http.Client{Transport: transport}
 
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
 		HTTPClient: supplied,
 	})
-	if err != nil {
-		t.Fatalf("unexpected constructor error: %v", err)
-	}
 
 	if supplied.Timeout != 0 {
 		t.Fatalf("expected supplied client timeout to remain zero, got %v", supplied.Timeout)
@@ -305,13 +276,10 @@ func TestNewOpenAICompatibleClientDoesNotMutateSuppliedNonzeroTimeoutClient(t *t
 		Transport: transport,
 	}
 
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
 		Timeout:    2 * time.Second,
 		HTTPClient: supplied,
 	})
-	if err != nil {
-		t.Fatalf("unexpected constructor error: %v", err)
-	}
 
 	if supplied.Timeout != suppliedTimeout {
 		t.Fatalf("expected supplied client timeout to remain %v, got %v", suppliedTimeout, supplied.Timeout)
@@ -335,13 +303,10 @@ func TestNewOpenAICompatibleClientTreatsSuppliedNegativeTimeoutAsUnset(t *testin
 	}
 	configuredTimeout := 23 * time.Second
 
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
 		Timeout:    configuredTimeout,
 		HTTPClient: supplied,
 	})
-	if err != nil {
-		t.Fatalf("unexpected constructor error: %v", err)
-	}
 
 	if supplied.Timeout != -time.Second {
 		t.Fatalf("expected supplied client timeout to remain negative, got %v", supplied.Timeout)
@@ -370,7 +335,6 @@ func TestOpenAICompatibleClientRequestMapping(t *testing.T) {
 		{name: "optional response fields", run: checkOptionalResponseFieldOmission},
 		{name: "reasoning and extra parameters", run: checkReasoningAndExtraParameterMapping},
 		{name: "optional request field presence", run: checkRequestFieldPresence},
-		{name: "configured model fallback", run: checkConfiguredModelFallback},
 	}
 
 	for _, tc := range tests {
@@ -380,14 +344,14 @@ func TestOpenAICompatibleClientRequestMapping(t *testing.T) {
 
 func checkCanonicalRoleAndExactContentMapping(t *testing.T) {
 	provider := newRecordingProvider(t)
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 	const content = "  exact content\nwith whitespace  "
 	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{
 			Role:    domain.RoleDeveloper,
 			Content: content,
 		}}},
-		Target: domain.ExecutionTarget{Model: "model"},
+		Target: domain.ExecutionTarget{Endpoint: provider.endpoint("/v1"), Model: "model"},
 	})
 	if err != nil {
 		t.Fatalf("Generate() error = %v", err)
@@ -413,7 +377,7 @@ func checkCompleteRequestAndResponseMapping(t *testing.T) {
   "usage": {"prompt_tokens": 11, "completion_tokens": 22, "total_tokens": 33}
 }`)
 
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
 		Timeout: 2 * time.Second,
 	})
 	t.Setenv("PROMPTKIT_TEST_API_KEY", "secret-key")
@@ -424,6 +388,7 @@ func checkCompleteRequestAndResponseMapping(t *testing.T) {
 			{Role: "user", Content: "Say hello"},
 		}},
 		Target: domain.ExecutionTarget{
+			Endpoint:    provider.endpoint("/v1"),
 			Model:       "gpt-test",
 			Temperature: 0.4,
 			MaxTokens:   123,
@@ -594,9 +559,11 @@ func TestOpenAICompatibleClientAuthentication(t *testing.T) {
 				tc.configureEnv(t)
 			}
 			provider := newRecordingProvider(t)
-			client := newProviderClient(t, provider, OpenAICompatibleConfig{Model: "model"})
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-			request := ordinaryGenerateRequest()
+			request := provider.generateRequest()
 			request.Target = tc.target
+			request.Target.Endpoint = provider.endpoint("/v1")
+			request.Target.Model = "model"
 
 			_, err := client.Generate(context.Background(), request)
 			if tc.wantError != nil {
@@ -625,7 +592,7 @@ func TestOpenAICompatibleClientAuthentication(t *testing.T) {
 
 func checkCacheControlledMessageMapping(t *testing.T) {
 	provider := newRecordingProvider(t)
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 
 	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{
@@ -639,7 +606,7 @@ func checkCacheControlledMessageMapping(t *testing.T) {
 			},
 			{Role: "user", Content: "Dynamic request."},
 		}},
-		Target: domain.ExecutionTarget{Model: "model"},
+		Target: domain.ExecutionTarget{Endpoint: provider.endpoint("/v1"), Model: "model"},
 	})
 	if err != nil {
 		t.Fatalf("expected no error, got %v", err)
@@ -691,7 +658,7 @@ func checkCacheControlledMessageMapping(t *testing.T) {
 
 func checkEmptyCacheControlTTLOmission(t *testing.T) {
 	provider := newRecordingProvider(t)
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 
 	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{
@@ -703,7 +670,7 @@ func checkEmptyCacheControlTTLOmission(t *testing.T) {
 				},
 			},
 		}},
-		Target: domain.ExecutionTarget{Model: "model"},
+		Target: domain.ExecutionTarget{Endpoint: provider.endpoint("/v1"), Model: "model"},
 	})
 	if err != nil {
 		t.Fatalf("expected no error, got %v", err)
@@ -745,8 +712,8 @@ func checkSessionIDMapping(t *testing.T) {
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			provider := newRecordingProvider(t)
-			client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-			request := ordinaryGenerateRequest()
+			request := provider.generateRequest()
 			request.Prompt.SessionID = tc.sessionID
 
 			if _, err := client.Generate(context.Background(), request); err != nil {
@@ -766,19 +733,14 @@ func checkSessionIDMapping(t *testing.T) {
 }
 
 func TestOpenAICompatibleClientRejectsTooLongSessionID(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-		BaseURL: "http://example.com/v1",
-		Model:   "model",
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
-	_, err = client.Generate(context.Background(), domain.GenerateRequest{
+	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{
 			SessionID: strings.Repeat("x", domain.SessionIDMaxLength+1),
 			Messages:  []domain.RenderedMessage{{Role: "user", Content: "hi"}},
 		},
+		Target: domain.ExecutionTarget{Endpoint: "http://example.com/v1", Model: "model"},
 	})
 	if err == nil {
 		t.Fatal("expected invalid request error")
@@ -828,9 +790,9 @@ func checkContentPresence(t *testing.T) {
     "cache_write_tokens": 5
   }
 }`)
-			client := newProviderClient(t, provider, OpenAICompatibleConfig{Model: "model"})
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 
-			response, err := client.Generate(context.Background(), ordinaryGenerateRequest())
+			response, err := client.Generate(context.Background(), provider.generateRequest())
 			if err != nil {
 				t.Fatalf("generate: %v", err)
 			}
@@ -865,10 +827,11 @@ func checkCacheUsageMapping(t *testing.T) {
     "cache_write_tokens": 60
   }
 }`)
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{Model: "model"})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 
 	resp, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+		Target: domain.ExecutionTarget{Endpoint: provider.endpoint("/v1"), Model: "model"},
 	})
 	if err != nil {
 		t.Fatalf("expected no error, got %v", err)
@@ -901,8 +864,8 @@ func TestOpenAICompatibleUsagePresence(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			provider := newRecordingProvider(t)
 			provider.respond(http.StatusOK, `{`+tc.usage+`"choices":[{"message":{"content":"ok"}}]}`)
-			client := newProviderClient(t, provider, OpenAICompatibleConfig{Model: "model"})
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-			resp, err := client.Generate(context.Background(), ordinaryGenerateRequest())
+			resp, err := client.Generate(context.Background(), provider.generateRequest())
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -913,17 +876,17 @@ func TestOpenAICompatibleUsagePresence(t *testing.T) {
 	}
 	provider := newRecordingProvider(t)
 	provider.respond(http.StatusOK, `{"usage":{"prompt_tokens":"seven"},"choices":[{"message":{"content":"ok"}}]}`)
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{Model: "model"})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-	if resp, err := client.Generate(context.Background(), ordinaryGenerateRequest()); resp != nil || !errors.Is(err, ErrMalformedResponse) {
+	if resp, err := client.Generate(context.Background(), provider.generateRequest()); resp != nil || !errors.Is(err, ErrMalformedResponse) {
 		t.Fatalf("invalid numeric usage response=%+v, error=%v", resp, err)
 	}
 }
 
 func checkOptionalResponseFieldOmission(t *testing.T) {
 	provider := newRecordingProvider(t)
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 
-	_, err := client.Generate(context.Background(), ordinaryGenerateRequest())
+	_, err := client.Generate(context.Background(), provider.generateRequest())
 	if err != nil {
 		t.Fatalf("expected no error, got %v", err)
 	}
@@ -938,11 +901,12 @@ func checkOptionalResponseFieldOmission(t *testing.T) {
 
 func checkReasoningAndExtraParameterMapping(t *testing.T) {
 	provider := newRecordingProvider(t)
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 
 	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
 		Target: domain.ExecutionTarget{
+			Endpoint:        provider.endpoint("/v1"),
 			Model:           "model",
 			ReasoningEffort: "high",
 			ExtraParams: map[string]any{
@@ -1020,8 +984,8 @@ func checkRequestFieldPresence(t *testing.T) {
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			provider := newRecordingProvider(t)
-			client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-			request := ordinaryGenerateRequest()
+			request := provider.generateRequest()
 			request.TargetPresence = tc.presence
 
 			if _, err := client.Generate(context.Background(), request); err != nil {
@@ -1073,21 +1037,17 @@ func checkOmittedGenerationTimeout(t *testing.T) {
 	transport := &deadlineCapturingTransport{}
 	clientTimeout := 5 * time.Second
 
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "http://example.com/v1",
 		Timeout: clientTimeout,
 		HTTPClient: &http.Client{
 			Transport: transport,
 		},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
 	before := time.Now()
-	_, err = client.Generate(context.Background(), domain.GenerateRequest{
+	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-		Target: domain.ExecutionTarget{Model: "model", TimeoutSeconds: 0},
+		Target: domain.ExecutionTarget{Endpoint: "http://example.com/v1", Model: "model", TimeoutSeconds: 0},
 	})
 	after := time.Now()
 	if err == nil {
@@ -1146,11 +1106,11 @@ func TestOpenAICompatibleClientRejectsInvalidExtraParamsBeforeProviderCall(t *te
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			provider := newRecordingProvider(t)
-			client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 
 			_, err := client.Generate(context.Background(), domain.GenerateRequest{
 				Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-				Target: domain.ExecutionTarget{Model: "model", ExtraParams: tc.extraParams},
+				Target: domain.ExecutionTarget{Endpoint: provider.endpoint("/v1"), Model: "model", ExtraParams: tc.extraParams},
 			})
 			if err == nil {
 				t.Fatal("expected invalid request error")
@@ -1192,8 +1152,8 @@ func TestOpenAICompatibleClientClassifiesSchemaEncodingFailures(t *testing.T) {
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			provider := newRecordingProvider(t)
-			client := newProviderClient(t, provider, OpenAICompatibleConfig{})
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-			request := ordinaryGenerateRequest()
+			request := provider.generateRequest()
 			request.Target.ExtraParams = tc.extraParams
 			request.StructuredOutput = &domain.StructuredOutputSpec{
 				Type: domain.StructuredOutputJSONSchema,
@@ -1218,30 +1178,12 @@ func TestOpenAICompatibleClientClassifiesSchemaEncodingFailures(t *testing.T) {
 	}
 }
 
-func checkConfiguredModelFallback(t *testing.T) {
-	provider := newRecordingProvider(t)
-	client := newProviderClient(t, provider, OpenAICompatibleConfig{Model: "default-model"})
-
-	_, err := client.Generate(context.Background(), domain.GenerateRequest{
-		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-		Target: domain.ExecutionTarget{},
-	})
-	if err != nil {
-		t.Fatalf("expected no error, got %v", err)
-	}
-	var model string
-	if !provider.lastRequest(t).decodeField(t, "model", &model) || model != "default-model" {
-		t.Fatalf("model = %q, want default-model", model)
-	}
-}
-
 func TestOpenAICompatibleClientEndpointComposition(t *testing.T) {
 	tests := []struct {
 		name string
 		run  func(*testing.T)
 	}{
-		{name: "request endpoint overrides configured endpoint", run: checkEndpointOverride},
+		{name: "request endpoint", run: checkSelectedEndpoint},
-		{name: "request endpoint works without configured endpoint", run: checkEmptyConfiguredEndpoint},
 		{name: "completion URL preserves valid base paths", run: checkCompletionURLComposition},
 		{name: "invalid selected endpoint fails before transport", run: checkInvalidSelectedEndpointRejection},
 		{name: "an endpoint is required", run: checkRequiredEndpoint},
@@ -1252,35 +1194,6 @@ func TestOpenAICompatibleClientEndpointComposition(t *testing.T) {
 	}
 }
 
-func checkEndpointOverride(t *testing.T) {
-	configuredProvider := newRecordingProvider(t)
-	configuredProvider.respond(http.StatusOK, `{"choices":[{"message":{"content":"default"}}]}`)
-	selectedProvider := newRecordingProvider(t)
-	selectedProvider.respond(http.StatusOK, `{"choices":[{"message":{"content":"override"}}]}`)
-
-	client := newProviderClient(t, configuredProvider, OpenAICompatibleConfig{Model: "m"})
-
-	resp, err := client.Generate(context.Background(), domain.GenerateRequest{
-		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-		Target: domain.ExecutionTarget{Endpoint: selectedProvider.endpoint("/v1")},
-	})
-	if err != nil {
-		t.Fatalf("expected no error, got %v", err)
-	}
-	if resp.Content != "override" {
-		t.Fatalf("expected override response, got %q", resp.Content)
-	}
-	if got := configuredProvider.requestCount(); got != 0 {
-		t.Fatalf("configured provider calls = %d, want 0", got)
-	}
-	if got := selectedProvider.requestCount(); got != 1 {
-		t.Fatalf("selected provider calls = %d, want 1", got)
-	}
-	if got := selectedProvider.lastRequest(t).url; got != "/v1/chat/completions" {
-		t.Fatalf("selected URL = %q, want /v1/chat/completions", got)
-	}
-}
-
 func checkCommonResponseFailures(t *testing.T) {
 	const sensitiveBody = `provider-secret-fragment request_payload_details`
 	tests := []struct {
@@ -1310,9 +1223,9 @@ func checkCommonResponseFailures(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			provider := newRecordingProvider(t)
 			provider.respond(tc.statusCode, tc.body)
-			client := newProviderClient(t, provider, OpenAICompatibleConfig{Model: "m"})
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
 
-			response, err := client.Generate(context.Background(), ordinaryGenerateRequest())
+			response, err := client.Generate(context.Background(), provider.generateRequest())
 			if response != nil {
 				t.Fatalf("expected no partial response, got %+v", response)
 			}
@@ -1357,9 +1270,7 @@ func checkSuccessfulResponseByteBoundary(t *testing.T) {
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			body := sizedSuccessResponseBody(tc.size)
-			client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-				BaseURL: "https://provider.example/v1",
-				Model:   "m",
 				HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
 					return &http.Response{
 						StatusCode:    http.StatusOK,
@@ -1370,12 +1281,10 @@ func checkSuccessfulResponseByteBoundary(t *testing.T) {
 					}, nil
 				})},
 			})
-			if err != nil {
-				t.Fatalf("construct client: %v", err)
-			}
 
 			response, err := client.Generate(context.Background(), domain.GenerateRequest{
 				Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+				Target: domain.ExecutionTarget{Endpoint: "https://provider.example/v1", Model: "m"},
 			})
 			if tc.wantErr {
 				if response != nil {
@@ -1425,9 +1334,7 @@ func checkContinuingOversizedResponse(t *testing.T) {
 		strings.NewReader(prefix),
 		continuation,
 	)}
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "https://provider.example/v1",
-		Model:   "m",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
 			return &http.Response{
 				StatusCode:    http.StatusOK,
@@ -1438,9 +1345,6 @@ func checkContinuingOversizedResponse(t *testing.T) {
 			}, nil
 		})},
 	})
-	if err != nil {
-		t.Fatalf("construct client: %v", err)
-	}
 
 	type outcome struct {
 		response *domain.GenerateResponse
@@ -1450,6 +1354,7 @@ func checkContinuingOversizedResponse(t *testing.T) {
 	go func() {
 		response, generateErr := client.Generate(context.Background(), domain.GenerateRequest{
 			Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+			Target: domain.ExecutionTarget{Endpoint: "https://provider.example/v1", Model: "m"},
 		})
 		done <- outcome{response: response, err: generateErr}
 	}()
@@ -1497,9 +1402,7 @@ func checkSingleResponseDocument(t *testing.T) {
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			body := &countingReadCloser{reader: strings.NewReader(tc.body)}
-			client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-				BaseURL: "https://provider.example/v1",
-				Model:   "m",
 				HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
 					return &http.Response{
 						StatusCode:    http.StatusOK,
@@ -1510,12 +1413,10 @@ func checkSingleResponseDocument(t *testing.T) {
 					}, nil
 				})},
 			})
-			if err != nil {
-				t.Fatalf("construct client: %v", err)
-			}
 
 			response, err := client.Generate(context.Background(), domain.GenerateRequest{
 				Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+				Target: domain.ExecutionTarget{Endpoint: "https://provider.example/v1", Model: "m"},
 			})
 			if tc.wantErr {
 				if response != nil {
@@ -1541,22 +1442,19 @@ func checkGenerationTimeoutPrecedence(t *testing.T) {
 	transport := &deadlineCapturingTransport{err: context.DeadlineExceeded}
 	generationTimeout := 2 * time.Second
 
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "http://example.com/v1",
-		Model:   "m",
 		HTTPClient: &http.Client{
 			Timeout:   10 * time.Second,
 			Transport: transport,
 		},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
 	before := time.Now()
-	_, err = client.Generate(context.Background(), domain.GenerateRequest{
+	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
 		Target: domain.ExecutionTarget{
+			Endpoint:       "http://example.com/v1",
+			Model:          "m",
 			TimeoutSeconds: int(generationTimeout / time.Second),
 		},
 	})
@@ -1578,25 +1476,22 @@ func checkGenerationTimeoutPrecedence(t *testing.T) {
 
 func checkCallerDeadlinePrecedence(t *testing.T) {
 	transport := &deadlineCapturingTransport{err: context.DeadlineExceeded}
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "http://example.com/v1",
-		Model:   "m",
 		HTTPClient: &http.Client{
 			Timeout:   10 * time.Second,
 			Transport: transport,
 		},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
 	callerDeadline := time.Now().Add(time.Second)
 	ctx, cancel := context.WithDeadline(context.Background(), callerDeadline)
 	defer cancel()
 
-	_, err = client.Generate(ctx, domain.GenerateRequest{
+	_, err := client.Generate(ctx, domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
 		Target: domain.ExecutionTarget{
+			Endpoint:       "http://example.com/v1",
+			Model:          "m",
 			TimeoutSeconds: 2,
 		},
 	})
@@ -1618,22 +1513,18 @@ func checkCallerDeadlinePrecedence(t *testing.T) {
 }
 
 func checkCallerCancellationIdentity(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "http://example.com/v1",
-		Model:   "m",
 		HTTPClient: &http.Client{
 			Transport: contextErrorTransport{},
 		},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
 
-	_, err = client.Generate(ctx, domain.GenerateRequest{
+	_, err := client.Generate(ctx, domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+		Target: domain.ExecutionTarget{Endpoint: "http://example.com/v1", Model: "m"},
 	})
 	if err == nil {
 		t.Fatal("expected cancellation error")
@@ -1647,21 +1538,17 @@ func checkCallerCancellationIdentity(t *testing.T) {
 }
 
 func checkExpiredCallerDeadlineIdentity(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "http://example.com/v1",
-		Model:   "m",
 		HTTPClient: &http.Client{
 			Transport: contextErrorTransport{},
 		},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
 	ctx, cancel := context.WithDeadline(context.Background(), time.Unix(1, 0))
 	defer cancel()
-	_, err = client.Generate(ctx, domain.GenerateRequest{
+	_, err := client.Generate(ctx, domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+		Target: domain.ExecutionTarget{Endpoint: "http://example.com/v1", Model: "m"},
 	})
 	if !errors.Is(err, ErrRequestFailed) || !errors.Is(err, context.DeadlineExceeded) {
 		t.Fatalf("expected request failure and caller deadline identities, got %v", err)
@@ -1669,20 +1556,16 @@ func checkExpiredCallerDeadlineIdentity(t *testing.T) {
 }
 
 func checkWholeRequestTimeoutIdentity(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "http://example.com/v1",
-		Model:   "m",
 		HTTPClient: &http.Client{
 			Timeout:   time.Millisecond,
 			Transport: waitingContextTransport{},
 		},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
-	_, err = client.Generate(context.Background(), domain.GenerateRequest{
+	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+		Target: domain.ExecutionTarget{Endpoint: "http://example.com/v1", Model: "m"},
 	})
 	if !errors.Is(err, ErrRequestFailed) || !errors.Is(err, context.DeadlineExceeded) {
 		t.Fatalf("expected request failure and client timeout identities, got %v", err)
@@ -1696,20 +1579,15 @@ func checkTransportFailureIdentityAndRedaction(t *testing.T) {
 		apiKey   = "sensitive-api-key"
 		content  = "sensitive prompt content"
 	)
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: endpoint,
-		Model:   "m",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
 			return nil, transportCause
 		})},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
-	_, err = client.Generate(context.Background(), domain.GenerateRequest{
+	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: content}}},
-		Target: domain.ExecutionTarget{APIKey: apiKey},
+		Target: domain.ExecutionTarget{Endpoint: endpoint, Model: "m", APIKey: apiKey},
 	})
 	if !errors.Is(err, ErrRequestFailed) || !errors.Is(err, transportCause) {
 		t.Fatalf("expected request failure and transport cause identities, got %v", err)
@@ -1726,13 +1604,7 @@ func checkTransportFailureIdentityAndRedaction(t *testing.T) {
 }
 
 func TestOpenAICompatibleClientRejectsInvalidExecutionSettings(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-		BaseURL: "http://example.com/v1",
-		Model:   "m",
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
 	type testCase struct {
 		name   string
@@ -1765,11 +1637,9 @@ func TestOpenAICompatibleClientRejectsInvalidExecutionSettings(t *testing.T) {
 	}
 }
 
-func checkEmptyConfiguredEndpoint(t *testing.T) {
+func checkSelectedEndpoint(t *testing.T) {
 	var selectedURL string
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "",
-		Model:   "m",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
 			selectedURL = req.URL.String()
 			return &http.Response{
@@ -1782,13 +1652,10 @@ func checkEmptyConfiguredEndpoint(t *testing.T) {
 			}, nil
 		})},
 	})
-	if err != nil {
-		t.Fatalf("expected empty configured base URL to be allowed, got %v", err)
-	}
 
 	response, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-		Target: domain.ExecutionTarget{Endpoint: "http://request-endpoint.example/v1"},
+		Target: domain.ExecutionTarget{Endpoint: "http://request-endpoint.example/v1", Model: "m"},
 	})
 	if err != nil {
 		t.Fatalf("generate with request endpoint: %v", err)
@@ -1817,9 +1684,7 @@ func checkCompletionURLComposition(t *testing.T) {
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			var selectedURL string
-			client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-				BaseURL: tc.baseURL,
-				Model:   "m",
 				HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
 					selectedURL = req.URL.String()
 					return &http.Response{
@@ -1830,12 +1695,10 @@ func checkCompletionURLComposition(t *testing.T) {
 					}, nil
 				})},
 			})
-			if err != nil {
-				t.Fatalf("construct client: %v", err)
-			}
 
-			_, err = client.Generate(context.Background(), domain.GenerateRequest{
+			_, err := client.Generate(context.Background(), domain.GenerateRequest{
 				Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+				Target: domain.ExecutionTarget{Endpoint: tc.baseURL, Model: "m"},
 			})
 			if err != nil {
 				t.Fatalf("generate: %v", err)
@@ -1860,21 +1723,16 @@ func checkInvalidSelectedEndpointRejection(t *testing.T) {
 	for _, endpoint := range invalidEndpoints {
 		t.Run(endpoint, func(t *testing.T) {
 			transportCalls := 0
-			client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-				BaseURL: "https://configured.example/v1",
-				Model:   "m",
 				HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
 					transportCalls++
 					return nil, errors.New("transport must not be called")
 				})},
 			})
-			if err != nil {
-				t.Fatalf("construct client: %v", err)
-			}
 
-			_, err = client.Generate(context.Background(), domain.GenerateRequest{
+			_, err := client.Generate(context.Background(), domain.GenerateRequest{
 				Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-				Target: domain.ExecutionTarget{Endpoint: endpoint},
+				Target: domain.ExecutionTarget{Endpoint: endpoint, Model: "m"},
 			})
 			if !errors.Is(err, ErrInvalidRequest) {
 				t.Fatalf("expected ErrInvalidRequest, got %v", err)
@@ -1890,17 +1748,11 @@ func checkInvalidSelectedEndpointRejection(t *testing.T) {
 }
 
 func checkRequiredEndpoint(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-		BaseURL: "",
-		Model:   "m",
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
 
-	_, err = client.Generate(context.Background(), domain.GenerateRequest{
+	_, err := client.Generate(context.Background(), domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-		Target: domain.ExecutionTarget{},
+		Target: domain.ExecutionTarget{Model: "m"},
 	})
 	if err == nil {
 		t.Fatal("expected endpoint-required error")
@@ -1909,3 +1761,13 @@ func checkRequiredEndpoint(t *testing.T) {
 		t.Fatalf("expected ErrInvalidRequest, got %v", err)
 	}
 }
+
+func TestOpenAICompatibleClientRequiresModel(t *testing.T) {
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
+	_, err := client.PrepareGeneration(domain.GenerateRequest{
+		Target: domain.ExecutionTarget{Endpoint: "https://provider.example/v1"},
+	})
+	if !errors.Is(err, ErrInvalidRequest) {
+		t.Fatalf("missing model error = %v, want invalid request", err)
+	}
+}

internal/llm/openrouter_authentication.go

@@ -0,0 +1,108 @@
+package llm
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/url"
+
+	"go.maximumdirect.net/promptkit/internal/domain"
+)
+
+const maxAuthenticationResponseBytes = 1 << 20
+
+// AuthenticationEvidence describes the observable result of a key probe.
+type AuthenticationEvidence struct {
+	HTTP         HTTPExecutionEvidence
+	Accepted     *bool
+	Overflow     bool
+	Unrecognized bool
+}
+
+// OpenRouterKeyEndpoint derives the default key endpoint from a base endpoint.
+func OpenRouterKeyEndpoint(base string) (string, error) {
+	return url.JoinPath(base, "key")
+}
+
+// ProbeOpenRouterKey executes and interprets an OpenRouter key request.
+func (c *OpenAICompatibleClient) ProbeOpenRouterKey(ctx context.Context, endpoint string, timeoutSeconds int, target domain.ExecutionTarget) (AuthenticationEvidence, error) {
+	parsed, err := url.Parse(endpoint)
+	if err != nil {
+		return AuthenticationEvidence{}, err
+	}
+	parsed.User = nil
+	response, evidence, requestErr := c.GetWithAuthenticationEvidence(ctx, parsed.String(), timeoutSeconds, target)
+	result := AuthenticationEvidence{HTTP: evidence}
+	if response != nil && response.Body != nil {
+		defer response.Body.Close()
+	}
+	if !evidence.ResponseReceived && response == nil {
+		return result, requestErr
+	}
+	status := evidence.HTTPStatus
+	if status == nil && response != nil {
+		status = &response.StatusCode
+	}
+	if status == nil {
+		result.Unrecognized = true
+		return result, nil
+	}
+	switch *status {
+	case http.StatusUnauthorized:
+		accepted := false
+		result.Accepted = &accepted
+	case http.StatusOK:
+		if response == nil || response.Body == nil {
+			result.Unrecognized = true
+			return result, nil
+		}
+		contents, err := io.ReadAll(io.LimitReader(response.Body, maxAuthenticationResponseBytes+1))
+		if err != nil && ctx.Err() != nil {
+			return result, ctx.Err()
+		}
+		if len(contents) > maxAuthenticationResponseBytes {
+			result.Overflow = true
+			return result, nil
+		}
+		if err != nil {
+			return result, err
+		}
+		if recognizedOpenRouterKeyResponse(contents) {
+			accepted := true
+			result.Accepted = &accepted
+		} else {
+			result.Unrecognized = true
+		}
+	}
+	return result, nil
+}
+
+func recognizedOpenRouterKeyResponse(contents []byte) bool {
+	var envelope map[string]json.RawMessage
+	if err := json.Unmarshal(contents, &envelope); err != nil || envelope == nil {
+		return false
+	}
+	var data map[string]json.RawMessage
+	if err := json.Unmarshal(envelope["data"], &data); err != nil || data == nil {
+		return false
+	}
+	label := bytes.TrimSpace(data["label"])
+	var labelValue string
+	if len(label) == 0 || label[0] != '"' || json.Unmarshal(label, &labelValue) != nil {
+		return false
+	}
+	freeTier := bytes.TrimSpace(data["is_free_tier"])
+	if !bytes.Equal(freeTier, []byte("true")) && !bytes.Equal(freeTier, []byte("false")) {
+		return false
+	}
+	decoder := json.NewDecoder(bytes.NewReader(data["usage"]))
+	decoder.UseNumber()
+	var number any
+	if decoder.Decode(&number) != nil {
+		return false
+	}
+	_, ok := number.(json.Number)
+	return ok
+}

internal/llm/openrouter_authentication_test.go

@@ -0,0 +1,134 @@
+package llm
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"go.maximumdirect.net/promptkit/internal/domain"
+)
+
+func TestProbeOpenRouterKey(t *testing.T) {
+	valid := `{"data":{"label":"x","is_free_tier":false,"usage":0}}`
+	for _, tc := range []struct {
+		name                   string
+		status                 int
+		body                   string
+		key                    string
+		accepted               *bool
+		unrecognized, overflow bool
+	}{
+		{name: "recognized", status: 200, body: valid, key: "secret", accepted: boolValue(true)},
+		{name: "exact limit", status: 200, body: valid + strings.Repeat(" ", maxAuthenticationResponseBytes-len(valid)), accepted: boolValue(true)},
+		{name: "unknown", status: 200, body: `{"data":{"label":"x","is_free_tier":false,"usage":"0"}}`, unrecognized: true},
+		{name: "trailing value", status: 200, body: valid + ` {}`, unrecognized: true},
+		{name: "overflow", status: 200, body: strings.Repeat("x", maxAuthenticationResponseBytes+1), overflow: true},
+		{name: "unauthorized anonymous", status: 401, accepted: boolValue(false)},
+		{name: "other status", status: 503},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			var authorization string
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+				if req.URL.User != nil {
+					t.Fatal("request retained URL credentials")
+				}
+				authorization = req.Header.Get("Authorization")
+				return &http.Response{StatusCode: tc.status, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(tc.body))}, nil
+			})}})
+			got, err := client.ProbeOpenRouterKey(context.Background(), "https://user:password@example.invalid/key", 0, domain.ExecutionTarget{APIKey: tc.key})
+			if err != nil {
+				t.Fatal(err)
+			}
+			if got.HTTP.Endpoint != "https://example.invalid/key" || got.HTTP.HTTPStatus == nil || *got.HTTP.HTTPStatus != tc.status || got.Unrecognized != tc.unrecognized || got.Overflow != tc.overflow {
+				t.Fatalf("evidence = %+v", got)
+			}
+			if (got.Accepted == nil) != (tc.accepted == nil) || got.Accepted != nil && *got.Accepted != *tc.accepted {
+				t.Fatalf("acceptance = %v", got.Accepted)
+			}
+			if (authorization != "") != (tc.key != "") || got.HTTP.CredentialsSupplied != (tc.key != "") {
+				t.Fatalf("credential evidence = %+v", got.HTTP)
+			}
+		})
+	}
+}
+
+func boolValue(value bool) *bool { return &value }
+
+type authenticationFailingBody struct{ err error }
+
+func (b authenticationFailingBody) Read([]byte) (int, error) { return 0, b.err }
+func (b authenticationFailingBody) Close() error             { return nil }
+
+func TestProbeOpenRouterKeyRetainsBodyFailure(t *testing.T) {
+	want := errors.New("interrupted")
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
+		return &http.Response{StatusCode: 200, Header: make(http.Header), Body: authenticationFailingBody{err: want}}, nil
+	})}})
+	got, err := client.ProbeOpenRouterKey(context.Background(), "https://example.invalid/key", 0, domain.ExecutionTarget{})
+	if !errors.Is(err, want) || !got.HTTP.ResponseReceived {
+		t.Fatalf("evidence = %+v, error = %v", got, err)
+	}
+}
+
+type observedAuthenticationBody struct {
+	reader io.Reader
+	read   int
+	closed bool
+}
+
+func (b *observedAuthenticationBody) Read(p []byte) (int, error) {
+	n, err := b.reader.Read(p)
+	b.read += n
+	return n, err
+}
+
+func (b *observedAuthenticationBody) Close() error {
+	b.closed = true
+	return nil
+}
+
+func TestProbeOpenRouterKeyBoundsAndClosesBodies(t *testing.T) {
+	for _, tc := range []struct {
+		name     string
+		status   int
+		wantRead int
+	}{
+		{"overflow", http.StatusOK, maxAuthenticationResponseBytes + 1},
+		{"unauthorized", http.StatusUnauthorized, 0},
+		{"other status", http.StatusServiceUnavailable, 0},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			body := &observedAuthenticationBody{reader: strings.NewReader(strings.Repeat("x", 2*maxAuthenticationResponseBytes))}
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
+				return &http.Response{StatusCode: tc.status, ContentLength: 1, Header: make(http.Header), Body: body}, nil
+			})}})
+			got, err := client.ProbeOpenRouterKey(context.Background(), "https://example.invalid/key", 0, domain.ExecutionTarget{})
+			if err != nil || body.read != tc.wantRead || !body.closed || got.Overflow != (tc.status == http.StatusOK) {
+				t.Fatalf("evidence = %+v, read = %d, closed = %v, error = %v", got, body.read, body.closed, err)
+			}
+		})
+	}
+}
+
+func TestOpenRouterKeyEndpoint(t *testing.T) {
+	got, err := OpenRouterKeyEndpoint("https://example.invalid/api/v1/")
+	if err != nil || got != "https://example.invalid/api/v1/key" {
+		t.Fatalf("endpoint = %q, error = %v", got, err)
+	}
+}
+
+func TestProbeOpenRouterKeyPreservesCancellation(t *testing.T) {
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+		<-req.Context().Done()
+		return nil, req.Context().Err()
+	})}})
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	got, err := client.ProbeOpenRouterKey(ctx, "https://example.invalid/key", 0, domain.ExecutionTarget{})
+	if !errors.Is(err, context.Canceled) || got.Accepted != nil || got.HTTP.ResponseReceived {
+		t.Fatalf("evidence = %+v, error = %v", got, err)
+	}
+}

internal/llm/prepare_generation_benchmark_test.go

@@ -12,13 +12,7 @@ import (
 var prepareGenerationBenchmarkSink *PreparedGeneration
 
 func BenchmarkPrepareGeneration(b *testing.B) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{})
-		BaseURL: "https://api.example.test/v1",
-		Model:   "benchmark-model",
-	})
-	if err != nil {
-		b.Fatalf("construct benchmark client: %v", err)
-	}
 
 	prompt := domain.RenderedPrompt{
 		Messages: []domain.RenderedMessage{{Role: "user", Content: "Summarize this request."}},
@@ -31,14 +25,14 @@ func BenchmarkPrepareGeneration(b *testing.B) {
 			name: "no_extras",
 			request: domain.GenerateRequest{
 				Prompt: prompt,
-				Target: domain.ExecutionTarget{Model: "benchmark-model"},
+				Target: domain.ExecutionTarget{Endpoint: "https://api.example.test/v1", Model: "benchmark-model"},
 			},
 		},
 		{
 			name: "small_extras",
 			request: domain.GenerateRequest{
 				Prompt: prompt,
-				Target: domain.ExecutionTarget{Model: "benchmark-model", ExtraParams: map[string]any{
+				Target: domain.ExecutionTarget{Endpoint: "https://api.example.test/v1", Model: "benchmark-model", ExtraParams: map[string]any{
 					"priority": "low",
 					"attempt":  3,
 					"enabled":  true,
@@ -49,7 +43,7 @@ func BenchmarkPrepareGeneration(b *testing.B) {
 			name: "1MiB_string_extra",
 			request: domain.GenerateRequest{
 				Prompt: prompt,
-				Target: domain.ExecutionTarget{Model: "benchmark-model", ExtraParams: map[string]any{
+				Target: domain.ExecutionTarget{Endpoint: "https://api.example.test/v1", Model: "benchmark-model", ExtraParams: map[string]any{
 					"payload": strings.Repeat("x", 1<<20),
 				}},
 			},
@@ -58,7 +52,7 @@ func BenchmarkPrepareGeneration(b *testing.B) {
 			name: "nested_json_extras",
 			request: domain.GenerateRequest{
 				Prompt: prompt,
-				Target: domain.ExecutionTarget{Model: "benchmark-model", ExtraParams: map[string]any{
+				Target: domain.ExecutionTarget{Endpoint: "https://api.example.test/v1", Model: "benchmark-model", ExtraParams: map[string]any{
 					"options": map[string]any{
 						"enabled": true,
 						"limits":  []any{2, 4, 8},
@@ -71,7 +65,7 @@ func BenchmarkPrepareGeneration(b *testing.B) {
 			name: "structured_output",
 			request: domain.GenerateRequest{
 				Prompt: prompt,
-				Target: domain.ExecutionTarget{Model: "benchmark-model"},
+				Target: domain.ExecutionTarget{Endpoint: "https://api.example.test/v1", Model: "benchmark-model"},
 				StructuredOutput: &domain.StructuredOutputSpec{
 					Type: domain.StructuredOutputJSONSchema,
 					JSONSchema: &domain.StructuredOutputJSONSpec{

internal/llm/prepared_generation_evidence_test.go

@@ -73,9 +73,7 @@ func TestPreparedGenerationEvidenceSeparatesResponseAndGenerationFacts(t *testin
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-				BaseURL: "https://provider.example/v1",
-				Model:   "model",
 				HTTPClient: &http.Client{Transport: roundTripFunc(func(request *http.Request) (*http.Response, error) {
 					response := responseFor(request, test.status, "")
 					response.Body = io.NopCloser(strings.NewReader(test.body))
@@ -83,9 +81,6 @@ func TestPreparedGenerationEvidenceSeparatesResponseAndGenerationFacts(t *testin
 					return response, nil
 				})},
 			})
-			if err != nil {
-				t.Fatal(err)
-			}
 			request := ordinaryGenerateRequest()
 			if test.structured {
 				request.StructuredOutput = &domain.StructuredOutputSpec{
@@ -136,9 +131,7 @@ func TestPreparedGenerationEvidenceSeparatesResponseAndGenerationFacts(t *testin
 func TestPreparedGenerationEvidenceRetainsDecodedResponseOnCancellation(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	body := `{"choices":[{"message":{"content":"ok"}}],"usage":{"prompt_tokens":0}}`
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "https://provider.example/v1",
-		Model:   "model",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(request *http.Request) (*http.Response, error) {
 			return &http.Response{
 				StatusCode:    http.StatusOK,
@@ -149,9 +142,6 @@ func TestPreparedGenerationEvidenceRetainsDecodedResponseOnCancellation(t *testi
 			}, nil
 		})},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 	prepared, err := client.PrepareGeneration(ordinaryGenerateRequest())
 	if err != nil {
 		t.Fatal(err)
@@ -174,16 +164,11 @@ func TestPreparedGenerationEvidenceRetainsDecodedResponseOnCancellation(t *testi
 
 func TestPreparedGenerationEvidenceRecordsStructuredRequestAtDispatch(t *testing.T) {
 	transportErr := errors.New("provider unavailable")
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "https://provider.example/v1",
-		Model:   "model",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
 			return nil, transportErr
 		})},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 	request := ordinaryGenerateRequest()
 	request.StructuredOutput = &domain.StructuredOutputSpec{
 		Type: domain.StructuredOutputJSONSchema,

internal/llm/prepared_generation_test.go

@@ -26,8 +26,7 @@ func TestPreparedGenerationFreezesPayloadAndAuthentication(t *testing.T) {
 			const envName = "PROMPTKIT_PREPARED_GENERATION_TEST_KEY"
 			t.Setenv(envName, tc.initialKey)
 			var bodies, auth, urls []string
-			client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+			client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-				BaseURL: "https://example.invalid/v1", Model: "default-model",
 				HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
 					body, err := io.ReadAll(req.Body)
 					if err != nil {
@@ -39,12 +38,9 @@ func TestPreparedGenerationFreezesPayloadAndAuthentication(t *testing.T) {
 					return &http.Response{StatusCode: http.StatusOK, Body: io.NopCloser(strings.NewReader(`{"choices":[{"message":{"content":"ok"}}]}`))}, nil
 				})},
 			})
-			if err != nil {
-				t.Fatal(err)
-			}
 			req := domain.GenerateRequest{
 				Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "original"}}},
-				Target: domain.ExecutionTarget{APIKeyEnv: envName},
+				Target: domain.ExecutionTarget{Endpoint: "https://example.invalid/v1", Model: "default-model", APIKeyEnv: envName},
 			}
 			prepared, err := client.PrepareGeneration(req)
 			if err != nil {
@@ -68,8 +64,7 @@ func TestPreparedGenerationFreezesPayloadAndAuthentication(t *testing.T) {
 func TestPreparedGenerationAttemptsHaveIndependentContextsAndCloseBodies(t *testing.T) {
 	var contexts []context.Context
 	var closed int
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "https://example.invalid/v1", Model: "model",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
 			if err := req.Context().Err(); err != nil {
 				return nil, err
@@ -81,12 +76,9 @@ func TestPreparedGenerationAttemptsHaveIndependentContextsAndCloseBodies(t *test
 			}}, nil
 		})},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 	prepared, err := client.PrepareGeneration(domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-		Target: domain.ExecutionTarget{TimeoutSeconds: 1},
+		Target: domain.ExecutionTarget{Endpoint: "https://example.invalid/v1", Model: "model", TimeoutSeconds: 1},
 	})
 	if err != nil {
 		t.Fatal(err)
@@ -115,17 +107,14 @@ func TestPreparedGenerationAttemptsHaveIndependentContextsAndCloseBodies(t *test
 }
 
 func TestPreparedGenerationRetainsUsageFromMalformedChoice(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "https://example.invalid/v1", Model: "model",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
 			return &http.Response{StatusCode: http.StatusOK, Body: io.NopCloser(strings.NewReader(`{"usage":{"prompt_tokens":0},"choices":[]}`))}, nil
 		})},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 	prepared, err := client.PrepareGeneration(domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+		Target: domain.ExecutionTarget{Endpoint: "https://example.invalid/v1", Model: "model"},
 	})
 	if err != nil {
 		t.Fatal(err)
@@ -137,17 +126,14 @@ func TestPreparedGenerationRetainsUsageFromMalformedChoice(t *testing.T) {
 }
 
 func TestPreparedGenerationDoesNotUseInvalidlyFramedUsage(t *testing.T) {
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "https://example.invalid/v1", Model: "model",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
 			return &http.Response{StatusCode: http.StatusOK, Body: io.NopCloser(strings.NewReader(`{"usage":{"prompt_tokens":9},"choices":[]}{}`))}, nil
 		})},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 	prepared, err := client.PrepareGeneration(domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+		Target: domain.ExecutionTarget{Endpoint: "https://example.invalid/v1", Model: "model"},
 	})
 	if err != nil {
 		t.Fatal(err)
@@ -160,17 +146,14 @@ func TestPreparedGenerationDoesNotUseInvalidlyFramedUsage(t *testing.T) {
 
 func TestPreparedGenerationRetainsReadCancellation(t *testing.T) {
 	closed := false
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "https://example.invalid/v1", Model: "model",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
 			return &http.Response{StatusCode: http.StatusOK, Body: &readErrorBody{err: context.Canceled, closed: &closed}}, nil
 		})},
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
 	prepared, err := client.PrepareGeneration(domain.GenerateRequest{
 		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+		Target: domain.ExecutionTarget{Endpoint: "https://example.invalid/v1", Model: "model"},
 	})
 	if err != nil {
 		t.Fatal(err)

internal/llm/provider_http_error_transport_test.go

@@ -127,9 +127,7 @@ func TestOpenAICompatibleClientNonSuccessBodyOwnership(t *testing.T) {
 func newNonSuccessResponseClient(t *testing.T, statusCode int, contentLength int64, body io.ReadCloser) *OpenAICompatibleClient {
 	t.Helper()
 
-	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
+	client := NewOpenAICompatibleClient(OpenAICompatibleConfig{
-		BaseURL: "https://provider.example/v1",
-		Model:   "m",
 		HTTPClient: &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
 			return &http.Response{
 				StatusCode:    statusCode,
@@ -138,8 +136,5 @@ func newNonSuccessResponseClient(t *testing.T, statusCode int, contentLength int
 			}, nil
 		})},
 	})
-	if err != nil {
-		t.Fatalf("construct client: %v", err)
-	}
 	return client
 }

internal/llm/response_read_error_test.go

@@ -0,0 +1,48 @@
+package llm
+
+import (
+	"errors"
+	"io"
+	"strings"
+	"testing"
+)
+
+type responseBytesAndError struct {
+	data []byte
+	err  error
+}
+
+func (r *responseBytesAndError) Read(p []byte) (int, error) {
+	if len(r.data) == 0 {
+		return 0, r.err
+	}
+	n := copy(p, r.data)
+	r.data = r.data[n:]
+	if len(r.data) == 0 {
+		return n, r.err
+	}
+	return n, nil
+}
+
+func TestSuccessfulResponseReadFailuresRetainCause(t *testing.T) {
+	cause := errors.New("private reader diagnostic")
+	for _, test := range []struct {
+		name, prefix string
+		together     bool
+	}{
+		{"partial", `{"choices":[`, false},
+		{"complete then failure", successfulProviderResponse, false},
+		{"bytes and error together", successfulProviderResponse, true},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			var reader io.Reader = io.MultiReader(strings.NewReader(test.prefix), failingReader{err: cause})
+			if test.together {
+				reader = &responseBytesAndError{data: []byte(test.prefix), err: cause}
+			}
+			_, err := decodeOpenAIChatResponse(reader)
+			if !errors.Is(err, ErrTransport) || !errors.Is(err, cause) || errors.Is(err, ErrMalformedResponse) || strings.Contains(err.Error(), cause.Error()) {
+				t.Fatalf("read failure = %v", err)
+			}
+		})
+	}
+}

internal/profile/repository.go

@@ -13,4 +13,5 @@ var ErrProfileNotFound = errors.New("execution profile not found")
 // Repository selects execution profiles from a captured index.
 type Repository interface {
 	GetProfile(ctx context.Context, id string) (*domain.ExecutionProfile, error)
+	GetProfileIdentity(ctx context.Context, id string) (string, error)
 }

internal/prompt/go_renderer.go

@@ -24,10 +24,6 @@ type goRenderer struct {
 	templates TemplateLookup
 }
 
-func NewGoRenderer() Renderer {
-	return &goRenderer{}
-}
-
 // NewCompiledRenderer renders definitions using templates captured with the
 // configuration snapshot. Per-call clones bind request-specific input helpers.
 func NewCompiledRenderer(templates TemplateLookup) Renderer {
@@ -56,13 +52,12 @@ func (r *goRenderer) Render(ctx context.Context, definition *domain.PromptDefini
 	funcs := template.FuncMap{
 		"input": resolver.resolve,
 	}
-	var compiled CompiledTemplates
+	if r.templates == nil {
-	if r.templates != nil {
+		return nil, fmt.Errorf("%w: captured templates are unavailable", ErrRenderFailure)
-		var found bool
+	}
-		compiled, found = r.templates.GetCompiledTemplates(definition.ID)
+	compiled, found := r.templates.GetCompiledTemplates(definition.ID)
-		if !found || len(compiled.Messages) != len(definition.Templates) {
+	if !found || len(compiled.Messages) != len(definition.Templates) {
-			return nil, fmt.Errorf("%w: captured templates are unavailable", ErrRenderFailure)
+		return nil, fmt.Errorf("%w: captured templates are unavailable", ErrRenderFailure)
-		}
 	}
 
 	if err := ctx.Err(); err != nil {
@@ -70,15 +65,11 @@ func (r *goRenderer) Render(ctx context.Context, definition *domain.PromptDefini
 	}
 	var sessionID string
 	var err error
-	if r.templates != nil {
+	if definition.SessionID != "" {
-		if definition.SessionID != "" {
+		if compiled.Session == nil {
-			if compiled.Session == nil {
+			return nil, fmt.Errorf("%w: captured session template is unavailable", ErrRenderFailure)
-				return nil, fmt.Errorf("%w: captured session template is unavailable", ErrRenderFailure)
-			}
-			sessionID, err = renderCompiledSessionID(ctx, compiled.Session, funcs, vars)
 		}
-	} else {
+		sessionID, err = renderCompiledSessionID(ctx, compiled.Session, funcs, vars)
-		sessionID, err = renderSessionID(ctx, definition.SessionID, funcs, vars)
 	}
 	if err != nil {
 		return nil, err
@@ -102,18 +93,12 @@ func (r *goRenderer) Render(ctx context.Context, definition *domain.PromptDefini
 		if err := ctx.Err(); err != nil {
 			return nil, err
 		}
-		var tmpl *template.Template
+		if compiled.Messages[i] == nil {
-		var parseErr error
+			return nil, fmt.Errorf("%w: captured message template is unavailable", ErrRenderFailure)
-		if r.templates != nil {
+		}
-			if compiled.Messages[i] == nil {
+		tmpl, parseErr := compiled.Messages[i].Clone()
-				return nil, fmt.Errorf("%w: captured message template is unavailable", ErrRenderFailure)
+		if parseErr == nil {
-			}
+			tmpl.Funcs(funcs)
-			tmpl, parseErr = compiled.Messages[i].Clone()
-			if parseErr == nil {
-				tmpl.Funcs(funcs)
-			}
-		} else {
-			tmpl, parseErr = parseTemplate(fmt.Sprintf("msg_%d", i), tmplMsg.Content, funcs)
 		}
 		if err := ctx.Err(); err != nil {
 			return nil, err
@@ -201,20 +186,6 @@ func (r *artifactTextResolver) resolve(name string) (string, error) {
 	return text, nil
 }
 
-func renderSessionID(ctx context.Context, raw string, funcs template.FuncMap, vars map[string]string) (string, error) {
-	if err := ctx.Err(); err != nil {
-		return "", err
-	}
-	tmpl, parseErr := parseTemplate("session_id", raw, funcs)
-	if err := ctx.Err(); err != nil {
-		return "", err
-	}
-	if parseErr != nil {
-		return "", fmt.Errorf("%w: session_id: %v", ErrInvalidTemplate, parseErr)
-	}
-	return executeSessionTemplate(ctx, tmpl, vars)
-}
-
 func renderCompiledSessionID(ctx context.Context, compiled *template.Template, funcs template.FuncMap, vars map[string]string) (string, error) {
 	if err := ctx.Err(); err != nil {
 		return "", err

internal/prompt/renderer_test.go

@@ -14,7 +14,6 @@ import (
 )
 
 func TestGoRenderer_Render(t *testing.T) {
-	renderer := NewGoRenderer()
 	ctx := context.Background()
 
 	inputs := map[string]*domain.Artifact{
@@ -33,7 +32,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -49,11 +48,11 @@ func TestGoRenderer_Render(t *testing.T) {
 		def := &domain.PromptDefinition{
 			Inputs: []domain.PromptInput{{Name: "transcript", Required: true}},
 			Templates: []domain.PromptMessageTemplate{
-				{Role: "user", Content: "From file: {{input \"transcript\"}}", ContentFile: "/tmp/user.tmpl"},
+				{Role: "user", Content: "From file: {{input \"transcript\"}}"},
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -71,7 +70,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -99,7 +98,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -129,7 +128,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -151,7 +150,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -169,7 +168,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, map[string]string{
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, map[string]string{
 			"tone":       "concise",
 			"session_id": "agent-session-123",
 		})
@@ -190,7 +189,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -208,7 +207,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		_, err := renderer.Render(ctx, def, inputs, vars)
+		_, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if !errors.Is(err, ErrRenderFailure) {
 			t.Fatalf("expected ErrRenderFailure, got %v", err)
 		}
@@ -223,7 +222,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		_, err := renderer.Render(ctx, def, inputs, map[string]string{
+		_, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, map[string]string{
 			"tone":       "concise",
 			"session_id": strings.Repeat("x", domain.SessionIDMaxLength+1),
 		})
@@ -241,7 +240,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		_, err := renderer.Render(ctx, def, inputs, map[string]string{
+		_, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, map[string]string{
 			"tone":       "concise",
 			"session_id": "session" + string([]byte{0xff}),
 		})
@@ -258,7 +257,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -278,7 +277,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		res, err := renderer.Render(ctx, def, inputs, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -298,7 +297,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		_, err := renderer.Render(ctx, def, inputs, vars)
+		_, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if !errors.Is(err, ErrRenderFailure) {
 			t.Fatalf("expected ErrRenderFailure, got %v", err)
 		}
@@ -315,7 +314,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		_, err := renderer.Render(ctx, def, map[string]*domain.Artifact{}, vars)
+		_, err := capturedTestRenderer(t, def).Render(ctx, def, map[string]*domain.Artifact{}, vars)
 		if !errors.Is(err, ErrMissingRequiredInput) {
 			t.Fatalf("expected ErrMissingRequiredInput, got %v", err)
 		}
@@ -329,9 +328,9 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		_, err := renderer.Render(ctx, def, inputs, vars)
+		_, err := CompileTemplate("message", def.Templates[0].Content)
-		if !errors.Is(err, ErrInvalidTemplate) {
+		if err == nil {
-			t.Fatalf("expected ErrInvalidTemplate, got %v", err)
+			t.Fatal("expected template compilation to fail")
 		}
 	})
 
@@ -343,7 +342,7 @@ func TestGoRenderer_Render(t *testing.T) {
 			},
 		}
 
-		_, err := renderer.Render(ctx, def, inputs, vars)
+		_, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if !errors.Is(err, ErrRenderFailure) {
 			t.Fatalf("expected ErrRenderFailure, got %v", err)
 		}
@@ -359,7 +358,7 @@ func TestGoRenderer_Render(t *testing.T) {
 				{Role: "", Content: "Hello"},
 			},
 		}
-		_, err := renderer.Render(ctx, def, inputs, vars)
+		_, err := capturedTestRenderer(t, def).Render(ctx, def, inputs, vars)
 		if !errors.Is(err, ErrInvalidMessageRole) {
 			t.Fatalf("expected ErrInvalidMessageRole, got %v", err)
 		}
@@ -371,7 +370,7 @@ func TestGoRenderer_Render(t *testing.T) {
 				{Role: " \u2003DeVeLoPeR\u2003 ", Content: "Hello"},
 			},
 		}
-		res, err := renderer.Render(ctx, def, nil, vars)
+		res, err := capturedTestRenderer(t, def).Render(ctx, def, nil, vars)
 		if err != nil {
 			t.Fatalf("unexpected error: %v", err)
 		}
@@ -385,7 +384,7 @@ func TestGoRenderer_Render(t *testing.T) {
 		def := &domain.PromptDefinition{
 			Templates: []domain.PromptMessageTemplate{{Role: unsupportedRole, Content: "Hello"}},
 		}
-		_, err := renderer.Render(ctx, def, nil, vars)
+		_, err := capturedTestRenderer(t, def).Render(ctx, def, nil, vars)
 		if !errors.Is(err, ErrInvalidMessageRole) {
 			t.Fatalf("expected ErrInvalidMessageRole, got %v", err)
 		}
@@ -396,9 +395,9 @@ func TestGoRenderer_Render(t *testing.T) {
 }
 
 func TestGoRendererCancellation(t *testing.T) {
-	t.Run("before session parsing", func(t *testing.T) {
+	t.Run("before rendering", func(t *testing.T) {
 		definition := &domain.PromptDefinition{
-			SessionID: "{{ malformed",
+			SessionID: "{{.session}}",
 			Templates: []domain.PromptMessageTemplate{
 				{Role: "user", Content: "not rendered"},
 			},
@@ -406,18 +405,11 @@ func TestGoRendererCancellation(t *testing.T) {
 		ctx, cancel := context.WithCancel(context.Background())
 		cancel()
 
-		result, err := NewGoRenderer().Render(ctx, definition, nil, nil)
+		renderer := capturedTestRenderer(t, definition)
+		result, err := renderer.Render(ctx, definition, nil, nil)
 		if result != nil || !errors.Is(err, context.Canceled) {
 			t.Fatalf("result=%#v err=%v, want nil/context.Canceled", result, err)
 		}
-		if errors.Is(err, ErrInvalidTemplate) {
-			t.Fatalf("pre-canceled render parsed the malformed session: %v", err)
-		}
-
-		result, err = NewGoRenderer().Render(context.Background(), definition, nil, nil)
-		if result != nil || !errors.Is(err, ErrInvalidTemplate) {
-			t.Fatalf("active render result=%#v err=%v, want nil/ErrInvalidTemplate", result, err)
-		}
 	})
 
 	t.Run("during artifact text conversion", func(t *testing.T) {
@@ -447,14 +439,15 @@ func TestGoRendererCancellation(t *testing.T) {
 			},
 		}
 		counter := &checkCountingContext{Context: context.Background()}
-		if _, err := NewGoRenderer().Render(counter, definition, nil, nil); err != nil {
+		renderer := capturedTestRenderer(t, definition)
+		if _, err := renderer.Render(counter, definition, nil, nil); err != nil {
 			t.Fatalf("count render checkpoints: %v", err)
 		}
 
 		// The final three checks occur after template execution, after the
 		// message is assembled, and immediately before publication.
 		ctx := newCancelOnCheckContext(counter.checks - 2)
-		result, err := NewGoRenderer().Render(ctx, definition, nil, nil)
+		result, err := renderer.Render(ctx, definition, nil, nil)
 		if result != nil || !errors.Is(err, context.Canceled) {
 			t.Fatalf("result=%#v err=%v, want nil/context.Canceled", result, err)
 		}
@@ -472,7 +465,8 @@ func TestGoRendererArtifactTextLifecycle(t *testing.T) {
 		},
 	}
 
-	first, err := NewGoRenderer().Render(context.Background(), definition, inputs, nil)
+	renderer := capturedTestRenderer(t, definition)
+	first, err := renderer.Render(context.Background(), definition, inputs, nil)
 	if err != nil {
 		t.Fatalf("first render: %v", err)
 	}
@@ -488,7 +482,7 @@ func TestGoRendererArtifactTextLifecycle(t *testing.T) {
 	if bytes.Equal([]byte(first.Messages[0].Content), append(append(append([]byte(nil), body...), '|'), body...)) {
 		t.Fatal("completed render aliases the artifact body")
 	}
-	second, err := NewGoRenderer().Render(context.Background(), definition, inputs, nil)
+	second, err := renderer.Render(context.Background(), definition, inputs, nil)
 	if err != nil {
 		t.Fatalf("second render: %v", err)
 	}
@@ -498,7 +492,7 @@ func TestGoRendererArtifactTextLifecycle(t *testing.T) {
 	}
 
 	nilInputs := map[string]*domain.Artifact{"document": nil}
-	result, err := NewGoRenderer().Render(context.Background(), definition, nilInputs, nil)
+	result, err := renderer.Render(context.Background(), definition, nilInputs, nil)
 	if result != nil || !errors.Is(err, ErrUnknownInput) || !errors.Is(err, ErrRenderFailure) {
 		t.Fatalf("nil input result=%#v err=%v, want ErrUnknownInput and ErrRenderFailure", result, err)
 	}
@@ -559,11 +553,56 @@ func TestCompiledRendererKeepsConcurrentRequestsIndependent(t *testing.T) {
 	}
 }
 
+func TestCompiledRendererRequiresCapturedTemplates(t *testing.T) {
+	message, err := CompileTemplate("message", "hello")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, tc := range []struct {
+		name      string
+		lookup    TemplateLookup
+		sessionID string
+	}{
+		{name: "missing lookup"},
+		{name: "missing prompt", lookup: compiledRendererTestLookup{id: "other"}},
+		{name: "missing message", lookup: compiledRendererTestLookup{id: "prompt"}},
+		{name: "nil message", lookup: compiledRendererTestLookup{id: "prompt", templates: CompiledTemplates{Messages: []*template.Template{nil}}}},
+		{name: "missing session", lookup: compiledRendererTestLookup{id: "prompt", templates: CompiledTemplates{Messages: []*template.Template{message}}}, sessionID: "session"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			definition := &domain.PromptDefinition{ID: "prompt", SessionID: tc.sessionID, Templates: []domain.PromptMessageTemplate{{Role: "user", Content: "hello"}}}
+			if _, err := NewCompiledRenderer(tc.lookup).Render(context.Background(), definition, nil, nil); !errors.Is(err, ErrRenderFailure) {
+				t.Fatalf("render error = %v, want render failure", err)
+			}
+		})
+	}
+}
+
 type compiledRendererTestLookup struct {
 	id        string
 	templates CompiledTemplates
 }
 
+func capturedTestRenderer(t testing.TB, definition *domain.PromptDefinition) Renderer {
+	t.Helper()
+	var compiled CompiledTemplates
+	var err error
+	if definition.SessionID != "" {
+		compiled.Session, err = CompileTemplate("session", definition.SessionID)
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+	for _, message := range definition.Templates {
+		parsed, err := CompileTemplate("message", message.Content)
+		if err != nil {
+			t.Fatal(err)
+		}
+		compiled.Messages = append(compiled.Messages, parsed)
+	}
+	return NewCompiledRenderer(compiledRendererTestLookup{id: definition.ID, templates: compiled})
+}
+
 func (lookup compiledRendererTestLookup) GetCompiledTemplates(id string) (CompiledTemplates, bool) {
 	if id != lookup.id {
 		return CompiledTemplates{}, false
@@ -571,8 +610,7 @@ func (lookup compiledRendererTestLookup) GetCompiledTemplates(id string) (Compil
 	return lookup.templates, true
 }
 
-// BenchmarkGoRendererArtifactReferences measures NewGoRenderer's per-call
+// BenchmarkGoRendererArtifactReferences measures rendering captured templates.
-// template-parsing fallback rather than the captured compiled path.
 func BenchmarkGoRendererArtifactReferences(b *testing.B) {
 	body := bytes.Repeat([]byte("document content "), (artifactTextChunkSize*4)/len("document content "))
 	inputs := map[string]*domain.Artifact{
@@ -604,7 +642,7 @@ func BenchmarkGoRendererArtifactReferences(b *testing.B) {
 
 	for _, tc := range tests {
 		b.Run(tc.name, func(b *testing.B) {
-			renderer := NewGoRenderer()
+			renderer := capturedTestRenderer(b, tc.definition)
 			b.ReportAllocs()
 			b.SetBytes(int64(len(body)))
 			for range b.N {

internal/prompt/requirements.go

@@ -319,24 +319,27 @@ func mergeConditionEvaluations(left, right conditionEvaluation) conditionEvaluat
 	result := conditionEvaluation{
 		unsupported:      left.unsupported || right.unsupported,
 		inputNameUnknown: left.inputNameUnknown || right.inputNameUnknown,
-		missingVariables: make(map[string]struct{}, len(left.missingVariables)+len(right.missingVariables)),
+		missingVariables: mergeOwnedNames(left.missingVariables, right.missingVariables),
-		contentInputs:    make(map[string]struct{}, len(left.contentInputs)+len(right.contentInputs)),
+		contentInputs:    mergeOwnedNames(left.contentInputs, right.contentInputs),
-	}
-	for name := range left.missingVariables {
-		result.missingVariables[name] = struct{}{}
-	}
-	for name := range right.missingVariables {
-		result.missingVariables[name] = struct{}{}
-	}
-	for name := range left.contentInputs {
-		result.contentInputs[name] = struct{}{}
-	}
-	for name := range right.contentInputs {
-		result.contentInputs[name] = struct{}{}
 	}
 	return result
 }
 
+// Condition results own their sets; callers retain operand values and flags,
+// not independent snapshots of these maps after a merge.
+func mergeOwnedNames(left, right map[string]struct{}) map[string]struct{} {
+	if len(left) < len(right) {
+		left, right = right, left
+	}
+	if left == nil {
+		return right
+	}
+	for name := range right {
+		left[name] = struct{}{}
+	}
+	return left
+}
+
 func branchReach(parent requirementReachability, known, truth, selected bool) requirementReachability {
 	if parent == requirementInactive {
 		return requirementInactive
@@ -448,6 +451,34 @@ func (walker *requirementWalker) walkTemplate(compiled *template.Template) error
 	return err
 }
 
+func (walker *requirementWalker) visitBranch(branch *parse.BranchNode, reach requirementReachability, dot dotIdentity, changesDot bool) error {
+	condition := conditionEvaluation{}
+	if reach == requirementInactive {
+		if err := walker.visit(branch.Pipe, requirementInactive, dot); err != nil {
+			return err
+		}
+	} else {
+		condition = walker.evaluateCondition(branch.Pipe, reach, dot)
+	}
+	before := walker.dependencies
+	bodyDot := dot
+	if changesDot {
+		bodyDot = walker.withDotIdentity(branch.Pipe, dot, condition)
+	}
+	thenReach := branchReach(reach, condition.known, condition.truth(), true)
+	elseReach := branchReach(reach, condition.known, condition.truth(), false)
+	if err := walker.visit(branch.List, thenReach, bodyDot); err != nil {
+		return err
+	}
+	if err := walker.visit(branch.ElseList, elseReach, dot); err != nil {
+		return err
+	}
+	if reach != requirementInactive && !condition.known && walker.dependencies != before {
+		walker.recordConditionLimitation(condition)
+	}
+	return nil
+}
+
 func (walker *requirementWalker) visit(node parse.Node, reach requirementReachability, dot dotIdentity) error {
 	if err := walker.ctx.Err(); err != nil {
 		return err
@@ -468,55 +499,9 @@ func (walker *requirementWalker) visit(node parse.Node, reach requirementReachab
 	case *parse.ActionNode:
 		return walker.visit(node.Pipe, reach, dot)
 	case *parse.IfNode:
-		if reach == requirementInactive {
+		return walker.visitBranch(&node.BranchNode, reach, dot, false)
-			if err := walker.visit(node.Pipe, requirementInactive, dot); err != nil {
-				return err
-			}
-			if err := walker.visit(node.List, requirementInactive, dot); err != nil {
-				return err
-			}
-			return walker.visit(node.ElseList, requirementInactive, dot)
-		}
-		condition := walker.evaluateCondition(node.Pipe, reach, dot)
-		before := walker.dependencies
-		thenReach := branchReach(reach, condition.known, condition.truth(), true)
-		elseReach := branchReach(reach, condition.known, condition.truth(), false)
-		if err := walker.visit(node.List, thenReach, dot); err != nil {
-			return err
-		}
-		if err := walker.visit(node.ElseList, elseReach, dot); err != nil {
-			return err
-		}
-		if !condition.known && walker.dependencies != before {
-			walker.recordConditionLimitation(condition)
-		}
-		return nil
 	case *parse.WithNode:
-		if reach == requirementInactive {
+		return walker.visitBranch(&node.BranchNode, reach, dot, true)
-			if err := walker.visit(node.Pipe, requirementInactive, dot); err != nil {
-				return err
-			}
-			bodyDot := walker.withDotIdentity(node.Pipe, dot, conditionEvaluation{})
-			if err := walker.visit(node.List, requirementInactive, bodyDot); err != nil {
-				return err
-			}
-			return walker.visit(node.ElseList, requirementInactive, dot)
-		}
-		condition := walker.evaluateCondition(node.Pipe, reach, dot)
-		before := walker.dependencies
-		thenReach := branchReach(reach, condition.known, condition.truth(), true)
-		elseReach := branchReach(reach, condition.known, condition.truth(), false)
-		bodyDot := walker.withDotIdentity(node.Pipe, dot, condition)
-		if err := walker.visit(node.List, thenReach, bodyDot); err != nil {
-			return err
-		}
-		if err := walker.visit(node.ElseList, elseReach, dot); err != nil {
-			return err
-		}
-		if !condition.known && walker.dependencies != before {
-			walker.recordConditionLimitation(condition)
-		}
-		return nil
 	case *parse.RangeNode:
 		if err := walker.visit(node.Pipe, reach, dot); err != nil {
 			return err

internal/prompt/requirements_test.go

@@ -314,7 +314,7 @@ func TestAnalyzeRequirementsClassifiesKnownConditions(t *testing.T) {
 				"active":   {Name: "active", Body: []byte("active")},
 				"inactive": {Name: "inactive", Body: []byte("inactive")},
 			}
-			rendered, err := NewGoRenderer().Render(context.Background(), definition, artifacts, test.vars)
+			rendered, err := capturedTestRenderer(t, definition).Render(context.Background(), definition, artifacts, test.vars)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -406,6 +406,35 @@ func TestAnalyzeRequirementsReportsUnresolvedDecisionAndContentConditions(t *tes
 	}
 }
 
+func TestConditionEvaluationMergesOwnedEvidence(t *testing.T) {
+	left := conditionEvaluation{missingVariables: map[string]struct{}{"a": {}, "b": {}}, contentInputs: map[string]struct{}{"document": {}}, unsupported: true}
+	right := conditionEvaluation{missingVariables: map[string]struct{}{"b": {}, "c": {}}, inputNameUnknown: true}
+	merged := mergeConditionEvaluations(left, right)
+	if !merged.unsupported || !merged.inputNameUnknown || len(merged.missingVariables) != 3 || len(merged.contentInputs) != 1 {
+		t.Fatalf("merged evidence = %+v", merged)
+	}
+	transferred := mergeConditionEvaluations(conditionEvaluation{}, conditionEvaluation{missingVariables: map[string]struct{}{"only": {}}})
+	if len(transferred.missingVariables) != 1 || transferred.contentInputs != nil {
+		t.Fatalf("transferred evidence = %+v", transferred)
+	}
+}
+
+func TestAnalyzeRequirementsRetainsLeftHeavyMissingConditions(t *testing.T) {
+	compiled := compileRequirementTemplate(t, "nested", `{{if eq (eq (eq .a .b) .c) .d}}{{input "yes"}}{{else}}{{input "no"}}{{end}}`)
+	result, err := AnalyzeRequirements(context.Background(), &domain.PromptDefinition{}, RequirementSnapshot{Templates: CompiledTemplates{Messages: []*template.Template{compiled}}}, nil, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if result.Complete || len(result.Variables) != 4 || len(result.Inputs) != 2 {
+		t.Fatalf("requirements = %+v", result)
+	}
+	for i, name := range []string{"a", "b", "c", "d"} {
+		if result.Variables[i].Name != name {
+			t.Fatalf("variables = %+v", result.Variables)
+		}
+	}
+}
+
 func TestAnalyzeRequirementsRetainsInactiveEntriesAndPromotesActiveUses(t *testing.T) {
 	description := "declared for a reason"
 	definition := &domain.PromptDefinition{Templates: []domain.PromptMessageTemplate{{
@@ -497,7 +526,7 @@ func TestAnalyzeRequirementsResolvesSimpleInputNames(t *testing.T) {
 				t.Fatalf("name-source caller key classification is incorrect: %+v", result.Variables)
 			}
 			artifacts := map[string]*domain.Artifact{inputName: {Name: inputName, Body: []byte("resolved")}}
-			rendered, err := NewGoRenderer().Render(context.Background(), definition, artifacts, test.vars)
+			rendered, err := capturedTestRenderer(t, definition).Render(context.Background(), definition, artifacts, test.vars)
 			if err != nil {
 				t.Fatal(err)
 			}

internal/promptdef/repository.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
+	"go.maximumdirect.net/promptkit/internal/prompt"
 )
 
 // ErrPromptDefinitionNotFound identifies an absent captured prompt definition.
@@ -12,5 +13,7 @@ var ErrPromptDefinitionNotFound = errors.New("prompt definition not found")
 
 // Repository selects prompt definitions from a captured index.
 type Repository interface {
-	GetPromptDefinition(ctx context.Context, id string) (*domain.PromptDefinition, error)
+	GetPromptSnapshot(ctx context.Context, id string) (*domain.PromptDefinition, string, error)
+	GetPromptInspection(ctx context.Context, id string) (*domain.PromptInspection, error)
+	GetRequirementSnapshot(id string) (prompt.RequirementSnapshot, bool)
 }

internal/usecase/operation_error.go

@@ -0,0 +1,38 @@
+package usecase
+
+import (
+	"errors"
+	"fmt"
+
+	"go.maximumdirect.net/promptkit/internal/profile"
+	"go.maximumdirect.net/promptkit/internal/promptdef"
+)
+
+// OperationError identifies the operation that owns a failure while retaining
+// the original cause for inspection.
+type OperationError struct {
+	Category error
+	Cause    error
+}
+
+func (e *OperationError) Error() string        { return fmt.Sprintf("%v: %v", e.Category, e.Cause) }
+func (e *OperationError) Unwrap() error        { return e.Cause }
+func (e *OperationError) Is(target error) bool { return target == e.Category }
+
+func promptLookupError(cause error) error {
+	category := ErrPromptLoad
+	if errors.Is(cause, promptdef.ErrPromptDefinitionNotFound) {
+		category = promptdef.ErrPromptDefinitionNotFound
+		cause = fmt.Errorf("%w: %w", ErrPromptLoad, cause)
+	}
+	return &OperationError{Category: category, Cause: cause}
+}
+
+func profileLookupError(cause error) error {
+	category := ErrProfileLoad
+	if errors.Is(cause, profile.ErrProfileNotFound) {
+		category = profile.ErrProfileNotFound
+		cause = fmt.Errorf("%w: %w", ErrProfileLoad, cause)
+	}
+	return &OperationError{Category: category, Cause: cause}
+}

internal/usecase/operation_error_test.go

@@ -0,0 +1,34 @@
+package usecase
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"go.maximumdirect.net/promptkit/internal/profile"
+	"go.maximumdirect.net/promptkit/internal/promptdef"
+)
+
+func TestOperationErrorRetainsOwnerAndCause(t *testing.T) {
+	cause := fmt.Errorf("nested: %w", promptdef.ErrPromptDefinitionNotFound)
+	outer := &OperationError{Category: ErrLLMGenerate, Cause: cause}
+	if !errors.Is(outer, ErrLLMGenerate) || !errors.Is(outer, promptdef.ErrPromptDefinitionNotFound) || errors.Unwrap(outer) != cause {
+		t.Fatalf("operation error = %v", outer)
+	}
+	for _, test := range []struct {
+		err      error
+		category error
+	}{
+		{promptLookupError(cause), promptdef.ErrPromptDefinitionNotFound},
+		{profileLookupError(profile.ErrProfileNotFound), profile.ErrProfileNotFound},
+		{promptLookupError(contextFailure), ErrPromptLoad},
+		{profileLookupError(contextFailure), ErrProfileLoad},
+	} {
+		var operation *OperationError
+		if !errors.As(test.err, &operation) || operation.Category != test.category {
+			t.Errorf("operation = %+v", operation)
+		}
+	}
+}
+
+var contextFailure = errors.New("lookup failed")

internal/usecase/output_contract_test.go

@@ -172,14 +172,13 @@ func TestRunnerRunRejectsInvalidOutputContractBeforeAdmission(t *testing.T) {
 func assertOutputContractCompletionSkipped(t *testing.T, collaborators outputContractTestCollaborators) {
 	t.Helper()
 	if collaborators.artifacts.calls != 0 || collaborators.renderer.calls != 0 ||
-		collaborators.validator.prepareCalls != 0 || collaborators.validator.directValidateCalls != 0 ||
+		collaborators.validator.prepareCalls != 0 ||
 		len(collaborators.admitter.backendIDs) != 0 || collaborators.llm.calls != 0 {
 		t.Fatalf(
-			"invalid output contract reached downstream work: artifacts=%d renderer=%d prepare_validation=%d validation=%d admissions=%d generation=%d",
+			"invalid output contract reached downstream work: artifacts=%d renderer=%d prepare_validation=%d admissions=%d generation=%d",
 			collaborators.artifacts.calls,
 			collaborators.renderer.calls,
 			collaborators.validator.prepareCalls,
-			collaborators.validator.directValidateCalls,
 			len(collaborators.admitter.backendIDs),
 			collaborators.llm.calls,
 		)

internal/usecase/prepared_execution.go

@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
-	"go.maximumdirect.net/promptkit/internal/jsonvalue"
 	"go.maximumdirect.net/promptkit/internal/observation"
 	"go.maximumdirect.net/promptkit/internal/validate"
 )
@@ -22,7 +21,7 @@ const (
 
 // PreparedExecution owns one frozen, single-use runner execution.
 type PreparedExecution struct {
-	owner   *Runner
+	owner   *runnerIdentity
 	mu      sync.Mutex
 	state   preparedExecutionState
 	details *domain.PreparedRun
@@ -50,24 +49,12 @@ func (r *Runner) PrepareExecution(ctx context.Context, req domain.RunRequest) (*
 		return nil, err
 	}
 
-	executionSnapshot := operation.run
-	extraParams, err := jsonvalue.CopyMap(executionSnapshot.EffectiveModelParams.ExtraParams)
-	if err != nil {
-		return nil, fmt.Errorf("%w: failed to copy prepared execution: %v", ErrInvalidRequest, err)
-	}
-	executionSnapshot.EffectiveModelParams.ExtraParams = extraParams
-
-	details, err := clonePreparedRun(executionSnapshot)
-	if err != nil {
-		return nil, fmt.Errorf("%w: failed to copy prepared execution details: %v", ErrInvalidRequest, err)
-	}
-
 	return &PreparedExecution{
-		owner:   r,
+		owner:   r.identity,
 		state:   preparedExecutionReady,
-		details: details,
+		details: operation.run,
 		payload: &preparedExecutionPayload{
-			prepared:         executionSnapshot,
+			prepared:         operation.run,
 			validation:       operation.validation,
 			directKey:        state.effectiveModel.APIKey,
 			transientRetries: state.transientRetries,
@@ -76,7 +63,8 @@ func (r *Runner) PrepareExecution(ctx context.Context, req domain.RunRequest) (*
 	}, nil
 }
 
-// Details returns a fresh credential-redacted copy of the prepared run.
+// Details returns immutable, credential-redacted metadata borrowed from the
+// handle. Callers must copy it before exposing it to mutable external code.
 func (p *PreparedExecution) Details() *domain.PreparedRun {
 	if p == nil {
 		return nil
@@ -85,11 +73,7 @@ func (p *PreparedExecution) Details() *domain.PreparedRun {
 	detailsSnapshot := p.details
 	p.mu.Unlock()
 
-	details, err := clonePreparedRun(detailsSnapshot)
+	return detailsSnapshot
-	if err != nil {
-		return nil
-	}
-	return details
 }
 
 // Discard invalidates an unclaimed execution and drops its private payload.
@@ -170,7 +154,7 @@ func (r *Runner) RunPrepared(ctx context.Context, prepared *PreparedExecution) (
 }
 
 func (p *PreparedExecution) claim(owner *Runner) (*preparedExecutionPayload, error) {
-	if p == nil || owner == nil || p.owner != owner {
+	if p == nil || owner == nil || owner.identity == nil || p.owner != owner.identity {
 		return nil, fmt.Errorf("%w: prepared execution does not belong to this runner", ErrInvalidRequest)
 	}
 
@@ -189,9 +173,6 @@ func (p *preparedExecutionPayload) clear() {
 	if p == nil {
 		return
 	}
-	if p.prepared != nil {
-		p.prepared.EffectiveModelParams.APIKey = ""
-	}
 	p.prepared = nil
 	p.validation = nil
 	p.directKey = ""
@@ -222,43 +203,3 @@ func (p noOpPreparedValidation) Validate(
 func (noOpPreparedValidation) SchemaDocument() any {
 	return nil
 }
-
-func clonePreparedRun(source *domain.PreparedRun) (*domain.PreparedRun, error) {
-	if source == nil {
-		return nil, nil
-	}
-
-	copied := *source
-	extraParams, err := jsonvalue.CopyMap(source.EffectiveModelParams.ExtraParams)
-	if err != nil {
-		return nil, err
-	}
-	copied.EffectiveModelParams.ExtraParams = extraParams
-
-	if source.InputHashes != nil {
-		copied.InputHashes = make(map[string]string, len(source.InputHashes))
-		for name, hash := range source.InputHashes {
-			copied.InputHashes[name] = hash
-		}
-	}
-	copied.Messages = domain.CloneRenderedMessages(source.Messages)
-
-	if source.StructuredOutput != nil {
-		structuredOutput := *source.StructuredOutput
-		copied.StructuredOutput = &structuredOutput
-		if source.StructuredOutput.JSONSchema != nil {
-			jsonSchema := *source.StructuredOutput.JSONSchema
-			copied.StructuredOutput.JSONSchema = &jsonSchema
-			schema, copyErr := cloneJSONValue(source.StructuredOutput.JSONSchema.Schema)
-			if copyErr != nil {
-				return nil, copyErr
-			}
-			copied.StructuredOutput.JSONSchema.Schema = schema
-		}
-	}
-	return &copied, nil
-}
-
-func cloneJSONValue(source any) (any, error) {
-	return jsonvalue.Copy(source)
-}

internal/usecase/prepared_execution_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
+	"go.maximumdirect.net/promptkit/internal/jsonvalue"
 	"go.maximumdirect.net/promptkit/internal/llm"
 	"go.maximumdirect.net/promptkit/internal/validate"
 )
@@ -47,25 +48,15 @@ func (p *recordingPreparedValidation) SchemaDocument() any {
 }
 
 type recordingValidationPreparer struct {
-	plan                *recordingPreparedValidation
+	plan         *recordingPreparedValidation
-	prepareErr          error
+	prepareErr   error
-	prepareCalls        int
+	prepareCalls int
-	directValidateCalls int
 }
 
-type validationOnly struct{}
+type nilPlanPreparer struct{}
 
-func (validationOnly) Validate(context.Context, *domain.Artifact, domain.OutputContract) (domain.ValidationResult, error) {
+func (nilPlanPreparer) PrepareValidation(context.Context, domain.OutputContract) (validate.PreparedValidation, error) {
-	return domain.ValidationResult{}, nil
+	return nil, nil
-}
-
-func (v *recordingValidationPreparer) Validate(
-	context.Context,
-	*domain.Artifact,
-	domain.OutputContract,
-) (domain.ValidationResult, error) {
-	v.directValidateCalls++
-	return domain.ValidationResult{}, errors.New("live validation must not be used")
 }
 
 func (v *recordingValidationPreparer) PrepareValidation(
@@ -129,12 +120,8 @@ func TestRunnerPrepareExecutionCompletesWithoutAdmissionOrGeneration(t *testing.
 	}
 	defer prepared.Discard()
 
-	if validator.prepareCalls != 1 || validator.directValidateCalls != 0 {
+	if validator.prepareCalls != 1 {
-		t.Fatalf(
+		t.Fatalf("validation preparations = %d, want 1", validator.prepareCalls)
-			"validation calls=(prepare=%d direct=%d), want (1, 0)",
-			validator.prepareCalls,
-			validator.directValidateCalls,
-		)
 	}
 	if reader.calls != 1 || renderer.calls != 1 {
 		t.Fatalf("completion calls=(artifact=%d render=%d), want (1, 1)", reader.calls, renderer.calls)
@@ -156,90 +143,37 @@ func TestRunnerPrepareExecutionCompletesWithoutAdmissionOrGeneration(t *testing.
 		t.Fatalf("prepared details have unexpected structured output: %#v", first.StructuredOutput)
 	}
 
-	first.Messages[0].Content = "caller mutation"
-	first.InputHashes["input"] = "caller mutation"
-	first.EffectiveModelParams.ExtraParams["metadata"].(map[string]any)["source"] = "caller mutation"
-	first.StructuredOutput.JSONSchema.Schema.(map[string]any)["type"] = "string"
 	renderer.rendered.Messages[0].Content = "source mutation"
 
 	second := prepared.Details()
-	if second.Messages[0].Content != "original message" ||
+	if second != first || second.Messages[0].Content != "original message" ||
-		second.InputHashes["input"] == "caller mutation" ||
 		second.EffectiveModelParams.ExtraParams["metadata"].(map[string]any)["source"] != "original" ||
 		second.StructuredOutput.JSONSchema.Schema.(map[string]any)["type"] != "object" {
-		t.Fatalf("details did not preserve an independent snapshot: %#v", second)
+		t.Fatalf("borrowed details did not preserve the snapshot: %#v", second)
 	}
 }
 
-func TestRunnerPreparationRejectsExcessivelyDeepPreparedSchema(t *testing.T) {
+func TestRunnerPreparationDetachesDeepPreparedSchema(t *testing.T) {
-	operations := []struct {
+	var nested any = "original"
-		name string
+	for range 150 {
-		run  func(*Runner, domain.RunRequest) error
+		nested = map[string]any{"child": nested}
-	}{
-		{
-			name: "Prepare",
-			run: func(runner *Runner, request domain.RunRequest) error {
-				_, err := runner.Prepare(context.Background(), request)
-				return err
-			},
-		},
-		{
-			name: "Run",
-			run: func(runner *Runner, request domain.RunRequest) error {
-				_, err := runner.Run(context.Background(), request)
-				return err
-			},
-		},
-		{
-			name: "PrepareExecution",
-			run: func(runner *Runner, request domain.RunRequest) error {
-				_, err := runner.PrepareExecution(context.Background(), request)
-				return err
-			},
-		},
 	}
-
+	schema := map[string]any{"annotation": nested}
-	for _, operation := range operations {
+	def := promptDef(domain.FormatJSON, domain.ValidationJSONSchema, 0)
-		t.Run(operation.name, func(t *testing.T) {
+	def.Validation.SchemaPath = "schema.json"
-			def := promptDef(domain.FormatJSON, domain.ValidationJSONSchema, 0)
+	validator := &recordingValidationPreparer{plan: &recordingPreparedValidation{schemaDocument: schema}}
-			def.Validation.SchemaPath = "schema.json"
+	runner := NewRunner(&fakePromptRepo{def: def},
-			llmClient := &fakeLLM{forbid: true}
+		&fakeExecutionProfileRepo{profiles: map[string]*domain.ExecutionProfile{"exec": defaultExecutionProfile()}},
-			validator := &recordingValidationPreparer{
+		defaultArtifactReader(), defaultRenderer(), &fakeLLM{forbid: true}, validator, nil)
-				plan: &recordingPreparedValidation{schemaDocument: excessivelyDeepPreparedJSONValue()},
+	prepared, err := runner.PrepareExecution(context.Background(), domain.RunRequest{PromptID: "p", ProfileID: "exec", Inputs: singleInputRef()})
-			}
+	if err != nil {
-			runner := NewRunner(
+		t.Fatalf("prepare execution: %v", err)
-				&fakePromptRepo{def: def},
-				&fakeExecutionProfileRepo{profiles: map[string]*domain.ExecutionProfile{"exec": defaultExecutionProfile()}},
-
-				defaultArtifactReader(),
-				defaultRenderer(),
-				llmClient,
-				validator,
-				nil,
-			)
-
-			err := operation.run(runner, domain.RunRequest{
-				PromptID:  "p",
-				ProfileID: "exec",
-				Inputs:    singleInputRef(),
-			})
-			if !errors.Is(err, ErrValidation) {
-				t.Fatalf("expected ErrValidation, got %v", err)
-			}
-			if llmClient.calls != 0 {
-				t.Fatalf("invalid prepared schema reached generation: %d calls", llmClient.calls)
-			}
-		})
 	}
-}
+	schema["annotation"].(map[string]any)["child"] = "source mutation"
-
+	first := prepared.Details().StructuredOutput.JSONSchema.Schema.(map[string]any)
-func excessivelyDeepPreparedJSONValue() any {
+	if _, ok := first["annotation"].(map[string]any)["child"].(map[string]any); !ok {
-	const clearlyUnsafeContainerDepth = 1_000
+		t.Fatal("prepared schema aliases the validator document")
-	var value any = true
-	for level := 0; level < clearlyUnsafeContainerDepth; level++ {
-		value = map[string]any{"child": value}
 	}
-	return value
 }
 
 func TestRunnerRunPreparedCredentialAvailabilityBeforeAdmission(t *testing.T) {
@@ -421,8 +355,8 @@ func TestRunnerRunPreparedUsesFrozenValidationForInitialAndRepairOutputs(t *test
 	if !reflect.DeepEqual(validator.plan.artifacts, []string{`{"broken":true}`, `{"repaired":true}`}) {
 		t.Fatalf("prepared validation artifacts=%#v", validator.plan.artifacts)
 	}
-	if validator.directValidateCalls != 0 || repairer.calls != 1 {
+	if repairer.calls != 1 {
-		t.Fatalf("validation/repair calls=(direct=%d repair=%d), want (0, 1)", validator.directValidateCalls, repairer.calls)
+		t.Fatalf("repair calls = %d, want 1", repairer.calls)
 	}
 	if len(client.requests) != 1 || len(repairer.reqs) != 1 ||
 		!reflect.DeepEqual(repairer.reqs[0].OriginalMessages, client.requests[0].Prompt.Messages) {
@@ -498,7 +432,7 @@ func TestRunnerRunPreparedReleasesAdmissionAcrossExecutionErrors(t *testing.T) {
 				}},
 			},
 			repairer:   &fakeRepairer{err: repairInvalidRequest},
-			wantError:  ErrInvalidRequest,
+			wantError:  ErrLLMGenerate,
 			wantSource: repairInvalidRequest,
 		},
 		{
@@ -600,6 +534,9 @@ func TestRunnerPreparedExecutionOwnershipUseAndDiscard(t *testing.T) {
 	}
 
 	owner := newRunner()
+	if other := newRunner(); owner.identity == nil || owner.identity == other.identity {
+		t.Fatal("constructed runners must have independent identity tokens")
+	}
 	prepared, err := owner.PrepareExecution(context.Background(), request)
 	if err != nil {
 		t.Fatalf("prepare execution: %v", err)
@@ -616,6 +553,9 @@ func TestRunnerPreparedExecutionOwnershipUseAndDiscard(t *testing.T) {
 	if prepared.Details() == nil {
 		t.Fatal("details unavailable after execution")
 	}
+	if prepared.owner != owner.identity || prepared.payload != nil {
+		t.Fatal("claimed handle retained payload or lost owner identity")
+	}
 
 	discarded, err := owner.PrepareExecution(context.Background(), request)
 	if err != nil {
@@ -623,6 +563,9 @@ func TestRunnerPreparedExecutionOwnershipUseAndDiscard(t *testing.T) {
 	}
 	discarded.Discard()
 	discarded.Discard()
+	if discarded.owner != owner.identity || discarded.payload != nil {
+		t.Fatal("discarded handle retained payload or lost owner identity")
+	}
 	if _, err := owner.RunPrepared(context.Background(), discarded); !errors.Is(err, ErrInvalidRequest) {
 		t.Fatalf("discarded execution error=%v, want ErrInvalidRequest", err)
 	}
@@ -687,7 +630,7 @@ func TestRunnerPreparedExecutionDetachesTransferredSnapshotSources(t *testing.T)
 			}
 			wantLabel := "profile source"
 			if test.requestOverride {
-				request.Execution = &domain.ExecutionTargetOverride{ExtraParams: requestExtras}
+				request.Execution = &domain.ExecutionTargetOverride{ExtraParams: jsonvalue.CloneTrusted(requestExtras).(map[string]any)}
 				wantLabel = "request source"
 			}
 
@@ -711,11 +654,6 @@ func TestRunnerPreparedExecutionDetachesTransferredSnapshotSources(t *testing.T)
 				details.StructuredOutput.JSONSchema.Schema.(map[string]any)["properties"].(map[string]any)["value"].(map[string]any)["type"] != "string" {
 				t.Fatalf("prepared details retained a source alias: %#v", details)
 			}
-			details.Messages[0].Content = "mutated details"
-			if again := prepared.Details(); again == nil || len(again.Messages) != 1 || again.Messages[0].Content != "captured rendering" {
-				t.Fatalf("details mutation escaped into the retained snapshot: %+v", again)
-			}
-
 			result, err := runner.RunPrepared(context.Background(), prepared)
 			if err != nil || result == nil || !result.Validation.IsValid || result.InputHashes["transcript"] != "captured-input-hash" {
 				t.Fatalf("run prepared snapshot=(%+v, %v)", result, err)
@@ -737,22 +675,6 @@ func TestRunnerPreparedExecutionDetachesTransferredSnapshotSources(t *testing.T)
 	}
 }
 
-func TestRunnerPrepareExecutionClassifiesExtraCopyFailureAsInvalidRequest(t *testing.T) {
-	profile := defaultExecutionProfile()
-	profile.ResolvedTarget.ExtraParams = map[string]any{"unsupported": func() {}}
-	runner := NewRunner(
-		&fakePromptRepo{def: promptDef(domain.FormatText, domain.ValidationNone, 0)},
-		&fakeExecutionProfileRepo{profiles: map[string]*domain.ExecutionProfile{"exec": profile}},
-		defaultArtifactReader(), defaultRenderer(), &fakeLLM{forbid: true}, nil, nil,
-	)
-	prepared, err := runner.PrepareExecution(context.Background(), domain.RunRequest{
-		PromptID: "p", ProfileID: "exec",
-	})
-	if prepared != nil || !errors.Is(err, ErrInvalidRequest) {
-		t.Fatalf("prepared execution copy failure=(%v, %v), want ErrInvalidRequest", prepared, err)
-	}
-}
-
 func TestRunnerPreparedExecutionWithoutValidatorSkipsValidation(t *testing.T) {
 	runner := NewRunner(
 		&fakePromptRepo{def: promptDef(domain.FormatJSON, domain.ValidationJSON, 0)},
@@ -782,7 +704,7 @@ func TestRunnerPreparedExecutionWithoutValidatorSkipsValidation(t *testing.T) {
 	}
 }
 
-func TestRunnerPrepareExecutionRequiresValidationPreparer(t *testing.T) {
+func TestRunnerPrepareExecutionRejectsNilValidationPlan(t *testing.T) {
 	reader := defaultArtifactReader()
 	runner := NewRunner(
 		&fakePromptRepo{def: promptDef(domain.FormatText, domain.ValidationBasic, 0)},
@@ -791,7 +713,7 @@ func TestRunnerPrepareExecutionRequiresValidationPreparer(t *testing.T) {
 		reader,
 		defaultRenderer(),
 		&fakeLLM{forbid: true},
-		validationOnly{},
+		nilPlanPreparer{},
 		nil,
 	)
 

internal/usecase/profile_inspection.go

@@ -7,7 +7,6 @@ import (
 	"strings"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
-	"go.maximumdirect.net/promptkit/internal/jsonvalue"
 )
 
 type resolvedProfileSelection struct {
@@ -15,10 +14,6 @@ type resolvedProfileSelection struct {
 	profile *domain.ExecutionProfile
 }
 
-type profileIdentityRepository interface {
-	GetProfileIdentity(context.Context, string) (string, error)
-}
-
 func (r *Runner) profileLookupID(profileID string) (string, error) {
 	if strings.TrimSpace(profileID) == "" {
 		return "", fmt.Errorf("%w: profile id is required", ErrInvalidRequest)
@@ -39,7 +34,7 @@ func (r *Runner) resolveProfileSelection(
 	}
 	selectedProfile, err := r.profiles.GetProfile(ctx, lookupID)
 	if err != nil {
-		return nil, fmt.Errorf("%w: %w", ErrProfileLoad, err)
+		return nil, profileLookupError(err)
 	}
 	if selectedProfile == nil {
 		return nil, fmt.Errorf("%w: profile repository returned nil profile", ErrProfileLoad)
@@ -61,18 +56,11 @@ func (r *Runner) resolveProfileIdentity(ctx context.Context, profileID string) (
 	if err != nil {
 		return "", err
 	}
-	if indexed, ok := r.profiles.(profileIdentityRepository); ok {
+	identity, err := r.profiles.GetProfileIdentity(ctx, lookupID)
-		identity, err := indexed.GetProfileIdentity(ctx, lookupID)
-		if err != nil {
-			return "", fmt.Errorf("%w: %w", ErrProfileLoad, err)
-		}
-		return identity, nil
-	}
-	selection, err := r.resolveProfileSelection(ctx, lookupID)
 	if err != nil {
-		return "", err
+		return "", profileLookupError(err)
 	}
-	return selection.id, nil
+	return identity, nil
 }
 
 func normalizeResolvedExecutionTarget(target domain.ExecutionTarget) (domain.ExecutionTarget, error) {
@@ -108,7 +96,7 @@ func (r *Runner) InspectProfile(
 	}
 	select {
 	case <-ctx.Done():
-		return nil, fmt.Errorf("%w: %w", ErrProfileLoad, ctx.Err())
+		return nil, &OperationError{Category: ErrProfileLoad, Cause: ctx.Err()}
 	default:
 	}
 
@@ -118,12 +106,6 @@ func (r *Runner) InspectProfile(
 	}
 	target, _ := resolveExecutionTarget(selection.profile, nil)
 	target.APIKey = ""
-	params, err := jsonvalue.CopyMap(target.ExtraParams)
-	if err != nil {
-		return nil, fmt.Errorf("%w: profile extra parameters: %w", ErrProfileLoad, err)
-	}
-	target.ExtraParams = params
-
 	return &domain.ProfileInspection{
 		ProfileID:            selection.id,
 		EffectiveModelParams: target,

internal/usecase/profile_inspection_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
+	"go.maximumdirect.net/promptkit/internal/jsonvalue"
 	"go.maximumdirect.net/promptkit/internal/profile"
 )
 
@@ -23,7 +24,21 @@ func (r *inspectionProfileRepository) GetProfile(_ context.Context, id string) (
 	if r.err != nil {
 		return nil, r.err
 	}
-	return r.profile, nil
+	if r.profile == nil {
+		return nil, nil
+	}
+	profile := *r.profile
+	if profile.ResolvedTarget != nil {
+		target := *profile.ResolvedTarget
+		target.ExtraParams = jsonvalue.CloneTrusted(target.ExtraParams).(map[string]any)
+		profile.ResolvedTarget = &target
+	}
+	return &profile, nil
+}
+
+func (r *inspectionProfileRepository) GetProfileIdentity(ctx context.Context, id string) (string, error) {
+	_, err := r.GetProfile(ctx, id)
+	return id, err
 }
 
 func TestRunnerInspectProfileUsesExactSnapshotAndCopiesTarget(t *testing.T) {

internal/usecase/prompt_inspection.go

@@ -13,10 +13,6 @@ type resolvedPromptDefinition struct {
 	hash       string
 }
 
-type promptInspectionRepository interface {
-	GetPromptInspection(context.Context, string) (*domain.PromptInspection, error)
-}
-
 func (r *Runner) resolvePromptDefinition(ctx context.Context, promptID string) (*resolvedPromptDefinition, error) {
 	if strings.TrimSpace(promptID) == "" {
 		return nil, fmt.Errorf("%w: prompt id is required", ErrInvalidRequest)
@@ -25,29 +21,14 @@ func (r *Runner) resolvePromptDefinition(ctx context.Context, promptID string) (
 		return nil, fmt.Errorf("%w: prompt repository is not configured", ErrPromptLoad)
 	}
 
-	var definition *domain.PromptDefinition
+	definition, hash, err := r.promptDefs.GetPromptSnapshot(ctx, promptID)
-	var hash string
-	var err error
-	if indexed, ok := r.promptDefs.(interface {
-		GetPromptSnapshot(context.Context, string) (*domain.PromptDefinition, string, error)
-	}); ok {
-		definition, hash, err = indexed.GetPromptSnapshot(ctx, promptID)
-	} else {
-		definition, err = r.promptDefs.GetPromptDefinition(ctx, promptID)
-	}
 	if err != nil {
-		return nil, fmt.Errorf("%w: %w", ErrPromptLoad, err)
+		return nil, promptLookupError(err)
 	}
 	if definition == nil {
 		return nil, fmt.Errorf("%w: prompt repository returned nil definition", ErrPromptLoad)
 	}
 
-	if hash == "" {
-		hash, err = hashPromptDefinition(definition)
-		if err != nil {
-			return nil, fmt.Errorf("%w: failed to hash prompt definition: %v", ErrPromptLoad, err)
-		}
-	}
 	return &resolvedPromptDefinition{definition: definition, hash: hash}, nil
 }
 
@@ -58,29 +39,14 @@ func (r *Runner) resolvePromptInspection(ctx context.Context, promptID string) (
 	if r == nil || r.promptDefs == nil {
 		return nil, fmt.Errorf("%w: prompt repository is not configured", ErrPromptLoad)
 	}
-	if indexed, ok := r.promptDefs.(promptInspectionRepository); ok {
+	inspection, err := r.promptDefs.GetPromptInspection(ctx, promptID)
-		inspection, err := indexed.GetPromptInspection(ctx, promptID)
-		if err != nil {
-			return nil, fmt.Errorf("%w: %w", ErrPromptLoad, err)
-		}
-		if inspection == nil {
-			return nil, fmt.Errorf("%w: prompt repository returned nil inspection", ErrPromptLoad)
-		}
-		return inspection, nil
-	}
-
-	selection, err := r.resolvePromptDefinition(ctx, promptID)
 	if err != nil {
-		return nil, err
+		return nil, promptLookupError(err)
 	}
-	definition := selection.definition
+	if inspection == nil {
-	return &domain.PromptInspection{
+		return nil, fmt.Errorf("%w: prompt repository returned nil inspection", ErrPromptLoad)
-		PromptID:         definition.ID,
+	}
-		PromptHash:       selection.hash,
+	return inspection, nil
-		DefaultProfileID: definition.DefaultProfile,
-		Inputs:           append([]domain.PromptInput(nil), definition.Inputs...),
-		OutputContract:   definition.Validation,
-	}, nil
 }
 
 // InspectPrompt resolves one explicit prompt without execution work.
@@ -90,7 +56,7 @@ func (r *Runner) InspectPrompt(ctx context.Context, promptID string) (*domain.Pr
 	}
 	select {
 	case <-ctx.Done():
-		return nil, fmt.Errorf("%w: %w", ErrPromptLoad, ctx.Err())
+		return nil, &OperationError{Category: ErrPromptLoad, Cause: ctx.Err()}
 	default:
 	}
 

internal/usecase/prompt_inspection_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"go.maximumdirect.net/promptkit/internal/domain"
+	"go.maximumdirect.net/promptkit/internal/prompt"
 	"go.maximumdirect.net/promptkit/internal/promptdef"
 )
 
@@ -23,20 +24,33 @@ type promptMetadataRepository struct {
 	lookupID      string
 }
 
-func (r *inspectionPromptRepository) GetPromptDefinition(
+func (r *inspectionPromptRepository) GetPromptSnapshot(
 	_ context.Context,
 	id string,
-) (*domain.PromptDefinition, error) {
+) (*domain.PromptDefinition, string, error) {
 	r.calls++
 	r.id = id
 	if r.err != nil {
-		return nil, r.err
+		return nil, "", r.err
 	}
-	return r.definition, nil
+	return r.definition, "captured-hash", nil
 }
 
-func (r *promptMetadataRepository) GetPromptDefinition(context.Context, string) (*domain.PromptDefinition, error) {
+func (r *inspectionPromptRepository) GetPromptInspection(ctx context.Context, id string) (*domain.PromptInspection, error) {
-	return nil, errors.New("full prompt definition should not be requested")
+	definition, hash, err := r.GetPromptSnapshot(ctx, id)
+	return fixturePromptInspection(definition, hash), err
+}
+
+func (*inspectionPromptRepository) GetRequirementSnapshot(string) (prompt.RequirementSnapshot, bool) {
+	return prompt.RequirementSnapshot{}, false
+}
+
+func (r *promptMetadataRepository) GetPromptSnapshot(context.Context, string) (*domain.PromptDefinition, string, error) {
+	return nil, "", errors.New("full prompt definition should not be requested")
+}
+
+func (*promptMetadataRepository) GetRequirementSnapshot(string) (prompt.RequirementSnapshot, bool) {
+	return prompt.RequirementSnapshot{}, false
 }
 
 func (r *promptMetadataRepository) GetPromptInspection(
@@ -71,15 +85,11 @@ func TestRunnerInspectPromptResolvesOneDefinitionWithoutExecutionCollaborators(t
 	if err != nil {
 		t.Fatalf("inspect prompt: %v", err)
 	}
-	wantHash, err := hashPromptDefinition(definition)
-	if err != nil {
-		t.Fatalf("hash prompt definition: %v", err)
-	}
 	if repository.calls != 1 || repository.id != " prompt-id " {
 		t.Fatalf("prompt lookup=(calls=%d id=%q), want one unchanged ID lookup", repository.calls, repository.id)
 	}
 	if inspection.PromptID != definition.ID ||
-		inspection.PromptHash != wantHash ||
+		inspection.PromptHash != "captured-hash" ||
 		inspection.DefaultProfileID != definition.DefaultProfile ||
 		!reflect.DeepEqual(inspection.Inputs, definition.Inputs) ||
 		inspection.OutputContract != definition.Validation {
@@ -96,7 +106,7 @@ func TestRunnerInspectPromptResolvesOneDefinitionWithoutExecutionCollaborators(t
 	}
 }
 
-func TestRunnerInspectPromptUsesOwnedMetadataWhenRepositorySupportsIt(t *testing.T) {
+func TestRunnerInspectPromptUsesOwnedCapturedMetadata(t *testing.T) {
 	repository := &promptMetadataRepository{inspection: domain.PromptInspection{
 		PromptID: "captured.prompt", PromptHash: "cached-prompt-hash",
 		DefaultProfileID: "partial-profile",
@@ -119,7 +129,7 @@ func TestRunnerInspectPromptUsesOwnedMetadataWhenRepositorySupportsIt(t *testing
 	}
 }
 
-func TestRunnerInspectPromptUsesCapturedHashWhenMetadataCapabilityIsAbsent(t *testing.T) {
+func TestRunnerInspectPromptUsesCapturedHashAndMetadata(t *testing.T) {
 	repository := &requirementInspectionPromptRepository{
 		definition: &domain.PromptDefinition{
 			ID: "captured.prompt", Inputs: []domain.PromptInput{{Name: "document"}},
@@ -128,7 +138,7 @@ func TestRunnerInspectPromptUsesCapturedHashWhenMetadataCapabilityIsAbsent(t *te
 	inspection, err := (&Runner{promptDefs: repository}).InspectPrompt(context.Background(), " requested-id ")
 	if err != nil || inspection.PromptID != "captured.prompt" ||
 		inspection.PromptHash != "captured-hash" || inspection.Inputs[0].Name != "document" {
-		t.Fatalf("captured-hash fallback inspection=(%+v, %v)", inspection, err)
+		t.Fatalf("captured inspection=(%+v, %v)", inspection, err)
 	}
 }
 

internal/usecase/repair_prefix.go

@@ -0,0 +1,48 @@
+package usecase
+
+import (
+	"encoding/json"
+	"strings"
+	"unicode/utf8"
+)
+
+// boundedDiagnosticJSON returns a JSON string prefix and whether it represents
+// the complete normalized input. It retains at most the useful prefix.
+func boundedDiagnosticJSON(value string, maxBytes int) ([]byte, bool) {
+	if maxBytes < 2 {
+		return nil, false
+	}
+	limit := maxBytes - 2
+	var prefix strings.Builder
+	used := 0
+	more := false
+	for i := 0; i < len(value); {
+		r, size := utf8.DecodeRuneInString(value[i:])
+		piece := value[i : i+size]
+		if r == utf8.RuneError && size == 1 {
+			piece = "\uFFFD"
+			i++
+			for i < len(value) {
+				r, size = utf8.DecodeRuneInString(value[i:])
+				if r != utf8.RuneError || size != 1 {
+					break
+				}
+				i++
+			}
+		} else {
+			i += size
+		}
+		if used+len(piece) > limit {
+			more = true
+			break
+		}
+		prefix.WriteString(piece)
+		used += len(piece)
+	}
+	normalized := prefix.String()
+	encoded, _ := json.Marshal(normalized)
+	if len(encoded) > maxBytes {
+		return truncateDiagnosticJSONValue(normalized, maxBytes), false
+	}
+	return encoded, !more
+}

internal/usecase/repair_prefix_test.go

@@ -0,0 +1,33 @@
+package usecase
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+	"unicode/utf8"
+)
+
+func TestBoundedDiagnosticJSON(t *testing.T) {
+	for _, input := range []string{"", "plain", "<&>\n\"", "雪☃", "a\xff\xfe\xffb", "\xff\xfe" + strings.Repeat("z", 100)} {
+		for budget := 0; budget <= 30; budget++ {
+			encoded, complete := boundedDiagnosticJSON(input, budget)
+			if budget < 2 {
+				if encoded != nil || complete {
+					t.Fatalf("budget %d: %q %v", budget, encoded, complete)
+				}
+				continue
+			}
+			if len(encoded) > budget || !utf8.Valid(encoded) {
+				t.Fatalf("budget %d: %q", budget, encoded)
+			}
+			var decoded string
+			if err := json.Unmarshal(encoded, &decoded); err != nil {
+				t.Fatal(err)
+			}
+			normalized := strings.ToValidUTF8(input, "\uFFFD")
+			if !strings.HasPrefix(normalized, decoded) || complete != (decoded == normalized) {
+				t.Fatalf("input %q budget %d: %q complete=%v normalized=%q", input, budget, decoded, complete, normalized)
+			}
+		}
+	}
+}

internal/usecase/repairer.go

@@ -117,27 +117,38 @@ func repairGuidance(mode domain.ValidationMode) (string, error) {
 }
 
 func formatRepairDiagnostics(errors []string) string {
-	diagnostics := make([]string, len(errors))
+	complete := []byte{'['}
-	for index, diagnostic := range errors {
+	fits := true
-		diagnostics[index] = strings.ToValidUTF8(diagnostic, "\uFFFD")
+	for _, diagnostic := range errors {
+		separator := 0
+		if len(complete) > 1 {
+			separator = 1
+		}
+		entry, whole := boundedDiagnosticJSON(diagnostic, maxRepairDiagnosticBytes-len(complete)-separator-1)
+		if !whole {
+			fits = false
+			break
+		}
+		if separator != 0 {
+			complete = append(complete, ',')
+		}
+		complete = append(complete, entry...)
 	}
-
+	if fits {
-	complete, _ := json.Marshal(diagnostics)
+		return string(append(complete, ']'))
-	if len(complete) <= maxRepairDiagnosticBytes {
-		return string(complete)
 	}
 
 	omission, _ := json.Marshal(omittedRepairDiagnostics)
 	encoded := make([]byte, 0, maxRepairDiagnosticBytes)
 	encoded = append(encoded, '[')
-	for _, diagnostic := range diagnostics {
+	for _, diagnostic := range errors {
-		entry, _ := json.Marshal(diagnostic)
 		separator := 0
 		if len(encoded) > 1 {
 			separator = 1
 		}
 		available := maxRepairDiagnosticBytes - len(encoded) - separator - 1 - len(omission) - 1
-		if len(entry) <= available {
+		entry, whole := boundedDiagnosticJSON(diagnostic, available)
+		if whole {
 			if separator != 0 {
 				encoded = append(encoded, ',')
 			}
@@ -151,7 +162,7 @@ func formatRepairDiagnostics(errors []string) string {
 		if separator != 0 {
 			encoded = append(encoded, ',')
 		}
-		encoded = append(encoded, truncateDiagnosticJSONValue(diagnostic, available)...)
+		encoded = append(encoded, entry...)
 		break
 	}
 	if len(encoded) > 1 {

internal/usecase/repairer_test.go

@@ -298,6 +298,23 @@ func TestFormatRepairDiagnosticsBoundsAndPreservesData(t *testing.T) {
 	}
 }
 
+func TestFormatRepairDiagnosticsEmptyAndEscapedOversize(t *testing.T) {
+	for _, values := range [][]string{nil, {}} {
+		if got := formatRepairDiagnostics(values); got != "[]" {
+			t.Fatalf("empty diagnostics = %q", got)
+		}
+	}
+	value := strings.Repeat("<&>\x00\xff\xfe", maxRepairDiagnosticBytes)
+	encoded := formatRepairDiagnostics([]string{value})
+	var got []string
+	if err := json.Unmarshal([]byte(encoded), &got); err != nil {
+		t.Fatal(err)
+	}
+	if len(encoded) > maxRepairDiagnosticBytes || len(got) != 2 || got[1] != omittedRepairDiagnostics || !strings.HasPrefix(strings.ToValidUTF8(value, "\uFFFD"), got[0]) {
+		t.Fatalf("oversize diagnostics length=%d, values=%d", len(encoded), len(got))
+	}
+}
+
 func manyRepairDiagnostics() []string {
 	diagnostics := make([]string, 1_000)
 	for index := range diagnostics {

internal/usecase/requirements_inspection.go

@@ -18,10 +18,6 @@ type RequirementInspectionRequest struct {
 	SessionID string
 }
 
-type requirementSnapshotRepository interface {
-	GetRequirementSnapshot(id string) (prompt.RequirementSnapshot, bool)
-}
-
 // InspectRequirements discovers prompt inputs and caller variables without
 // loading artifacts or performing execution preparation.
 func (r *Runner) InspectRequirements(
@@ -36,7 +32,7 @@ func (r *Runner) InspectRequirements(
 		return nil, fmt.Errorf("%w: session_id: %v", ErrInvalidRequest, err)
 	}
 	if err := ctx.Err(); err != nil {
-		return nil, fmt.Errorf("%w: %w", ErrPromptLoad, err)
+		return nil, &OperationError{Category: ErrPromptLoad, Cause: err}
 	}
 
 	selection, err := r.resolvePromptInspection(ctx, req.PromptID)
@@ -44,7 +40,7 @@ func (r *Runner) InspectRequirements(
 		return nil, err
 	}
 	if err := ctx.Err(); err != nil {
-		return nil, fmt.Errorf("%w: %w", ErrProfileLoad, err)
+		return nil, &OperationError{Category: ErrProfileLoad, Cause: err}
 	}
 	selectedProfileID := req.ProfileID
 	if strings.TrimSpace(selectedProfileID) == "" {
@@ -58,21 +54,17 @@ func (r *Runner) InspectRequirements(
 		return nil, err
 	}
 	if err := ctx.Err(); err != nil {
-		return nil, fmt.Errorf("%w: %w", ErrPromptLoad, err)
+		return nil, &OperationError{Category: ErrPromptLoad, Cause: err}
 	}
 
-	repository, ok := r.promptDefs.(requirementSnapshotRepository)
+	snapshot, ok := r.promptDefs.GetRequirementSnapshot(selection.PromptID)
-	if !ok {
-		return nil, fmt.Errorf("%w: prompt repository does not provide captured requirement snapshots", ErrPromptLoad)
-	}
-	snapshot, ok := repository.GetRequirementSnapshot(selection.PromptID)
 	if !ok {
 		return nil, fmt.Errorf("%w: captured requirement snapshot is unavailable", ErrPromptLoad)
 	}
 	definition := &domain.PromptDefinition{ID: selection.PromptID}
 	inspection, err := prompt.AnalyzeRequirements(ctx, definition, snapshot, req.Vars, directSessionID != "")
 	if err != nil {
-		return nil, fmt.Errorf("%w: %w", ErrPromptLoad, err)
+		return nil, &OperationError{Category: ErrPromptLoad, Cause: err}
 	}
 	inspection.ProfileID = profileIdentity
 	return &inspection, nil