diff --git a/docs/roadmap/implementation.md b/docs/roadmap/implementation.md
index f1f8ba3..9a8b33c 100644
--- a/docs/roadmap/implementation.md
+++ b/docs/roadmap/implementation.md
@@ -243,6 +243,14 @@ Validation: inspect the registration selectors and schema; when runnable, load
 one headerless root list and one version-2 collection. Resolution/validation
 callers are completed in the following stages.
 
+Completion: the typed document now uses identified resource slices, registers
+all six root and collection identity rules, and checks specification version 2.
+Added a focused root/collection list fixture and reviewed the selectors and
+schema. The focused test cannot yet compile because field capture, resolution,
+validation, indexing, prompt materialization, and older fixtures still expect
+maps; those migrations are assigned to the following stages. Formatting and
+`git diff --check` passed; execution of the new fixture remains deferred.
+
 ## Stage 4: Preserve Field Presence And Resolution At List Paths
 
 Scope: backend/profile field capture, normalization, and defaulting in
diff --git a/internal/configuration/load.go b/internal/configuration/load.go
index 6853fd8..aa9727d 100644
--- a/internal/configuration/load.go
+++ b/internal/configuration/load.go
@@ -18,20 +18,21 @@ import (
 
 type document struct {
 	Version     *string                     `yaml:"version"`
-	Backends    map[string]backendConfig    `yaml:"backends"`
-	Profiles    map[string]profileConfig    `yaml:"profiles"`
-	Prompts     map[string]promptConfig     `yaml:"prompts"`
+	Backends    []backendConfig             `yaml:"backends"`
+	Profiles    []profileConfig             `yaml:"profiles"`
+	Prompts     []promptConfig              `yaml:"prompts"`
 	Collections map[string]collectionConfig `yaml:"collections"`
 }
 
 type collectionConfig struct {
-	ReleaseVersion *string                  `yaml:"release_version"`
-	Backends       map[string]backendConfig `yaml:"backends"`
-	Profiles       map[string]profileConfig `yaml:"profiles"`
-	Prompts        map[string]promptConfig  `yaml:"prompts"`
+	ReleaseVersion *string         `yaml:"release_version"`
+	Backends       []backendConfig `yaml:"backends"`
+	Profiles       []profileConfig `yaml:"profiles"`
+	Prompts        []promptConfig  `yaml:"prompts"`
 }
 
 type backendConfig struct {
+	ID               string                  `yaml:"id"`
 	Endpoint         *string                 `yaml:"endpoint"`
 	APIKeyEnv        *string                 `yaml:"api_key_env"`
 	ConcurrencyLimit *int                    `yaml:"concurrency_limit"`
@@ -56,6 +57,7 @@ type authenticationProbeConfig struct {
 }
 
 type profileConfig struct {
+	ID              string         `yaml:"id"`
 	Backend         *string        `yaml:"backend"`
 	Endpoint        *string        `yaml:"endpoint"`
 	Model           *string        `yaml:"model"`
@@ -71,7 +73,7 @@ type profileConfig struct {
 }
 
 type promptConfig struct {
-	Version        *string               `yaml:"version"`
+	ID             string                `yaml:"id"`
 	DefaultProfile *string               `yaml:"default_profile"`
 	Description    *string               `yaml:"description"`
 	SessionID      *string               `yaml:"session_id"`
@@ -141,9 +143,9 @@ type resourceSet struct {
 	isCollection bool
 	namespace    string
 	bases        resourceBases
-	backends     map[string]backendConfig
-	profiles     map[string]profileConfig
-	prompts      map[string]promptConfig
+	backends     []backendConfig
+	profiles     []profileConfig
+	prompts      []promptConfig
 }
 
 func rootResourceBases() resourceBases {
@@ -230,6 +232,14 @@ func load(main configkit.Input, underlays []configkit.Underlay) (*loaded, error)
 		Underlays:         underlays,
 		SourceVersionMode: configkit.SourceVersionModeIfPresent,
 		Definition: configkit.Definition[document]{
+			SequenceIdentities: []configkit.SequenceIdentity{
+				configkit.SequenceIdentityAt(configkit.Keys("backends"), "id"),
+				configkit.SequenceIdentityAt(configkit.Keys("profiles"), "id"),
+				configkit.SequenceIdentityAt(configkit.Keys("prompts"), "id"),
+				configkit.SequenceIdentityMatching(configkit.SequenceSelector{configkit.SequenceLiteralKey("collections"), configkit.SequenceAnyMappingKey(), configkit.SequenceLiteralKey("backends")}, "id"),
+				configkit.SequenceIdentityMatching(configkit.SequenceSelector{configkit.SequenceLiteralKey("collections"), configkit.SequenceAnyMappingKey(), configkit.SequenceLiteralKey("profiles")}, "id"),
+				configkit.SequenceIdentityMatching(configkit.SequenceSelector{configkit.SequenceLiteralKey("collections"), configkit.SequenceAnyMappingKey(), configkit.SequenceLiteralKey("prompts")}, "id"),
+			},
 			Version: &configkit.VersionRule{
 				Path:  configkit.Keys("version"),
 				Check: checkConfigurationVersion,
@@ -302,7 +312,7 @@ func checkConfigurationVersion(version configkit.Version, validation *configkit.
 	if !version.Present {
 		return nil
 	}
-	if version.Null || version.Text != "1" {
+	if version.Null || version.Text != "2" {
 		validation.Error(configkit.Keys("version"), "unsupported configuration specification version")
 	}
 	return nil
diff --git a/internal/configuration/load_test.go b/internal/configuration/load_test.go
index 6a6ef3f..382a58c 100644
--- a/internal/configuration/load_test.go
+++ b/internal/configuration/load_test.go
@@ -12,6 +12,27 @@ func mapping(label string, values map[string]any) configkit.Input {
 	return configkit.Input{Source: configkit.Mapping(label, values)}
 }
 
+func TestLoadIdentifiedResourceLists(t *testing.T) {
+	for _, header := range []bool{false, true} {
+		values := map[string]any{
+			"backends": []any{map[string]any{"id": "local", "endpoint": "https://example.invalid/v1"}},
+			"collections": map[string]any{"team": map[string]any{
+				"backends": []any{map[string]any{"id": "local", "endpoint": "https://example.invalid/v1"}},
+			}},
+		}
+		if header {
+			values["version"] = "2"
+		}
+		loaded, err := load(mapping("identified resources", values), nil)
+		if err != nil {
+			t.Fatalf("load identified resources with header %t: %v", header, err)
+		}
+		if loaded.result.Config.Backends[0].ID != "local" || loaded.result.Config.Collections["team"].Backends[0].ID != "local" {
+			t.Fatal("identified root and collection resources were not retained")
+		}
+	}
+}
+
 func TestLoadChecksOptionalConfigurationVersion(t *testing.T) {
 	for _, test := range []struct {
 		name    string