diff --git a/docs/roadmap/implementation.md b/docs/roadmap/implementation.md
index a0ed38e..d89d7d2 100644
--- a/docs/roadmap/implementation.md
+++ b/docs/roadmap/implementation.md
@@ -1,6 +1,6 @@
 # Interface Contract Remediation Implementation Plan
 
-Status: in progress. Stages 1–15 are complete; Stages 16–18 remain pending.
+Status: in progress. Stages 1–16 are complete; Stages 17–18 remain pending.
 Baseline: `f6d54a094a2b5ada5748686620659399dce7ebf0`.
 Audience: a Luna coding agent executing the stages sequentially.
 
@@ -692,7 +692,9 @@ quota or representation-specific node total is promised. Focused check:
 ## Stage 16 — Remove Superseded Attribution And Repair Test Seams
 
 Owners: all entries in the migration map and tests constructing private inspection
-or metadata values. Status: pending.
+or metadata values. Status: complete. Validation: `GOTOOLCHAIN=local
+GOPROXY=off GOTELEMETRY=off go test ./internal/engine` and
+`GOTOOLCHAIN=local GOPROXY=off GOTELEMETRY=off go test ./...` passed.
 
 1. Trace remaining production reads/writes of old history/inheritance fields and
    helpers. Remove history-building portions of `metadataFromDecoded`,
diff --git a/internal/engine/history_budget_test.go b/internal/engine/history_budget_test.go
index b82534e..ea3c47c 100644
--- a/internal/engine/history_budget_test.go
+++ b/internal/engine/history_budget_test.go
@@ -231,11 +231,12 @@ func TestPreparedInheritanceEvidenceSharesOwnerAndDetachesPublicViews(t *testing
 	builder.observeBaseline(baseline)
 	builder.setScratch(input)
 	builder.observeInheritanceEvidence(expanded.operations)
+	builder.observePreCLICheckpoint(expanded.root, expanded.origins)
+	builder.observePostCLICheckpoint(expanded.root, expanded.origins)
+	builder.prefixReady = true
 	metadata := Metadata{historyBuilder: builder}
 	resolved := resolvedLoad[historyBudgetSimpleConfig]{
-		metadata: metadata, historyBuilder: builder, final: expanded.root,
-		decoded: decodedConfiguration{baseline: baseline}, structuralInput: input,
-		inheritance: expanded,
+		metadata: metadata, final: expanded.root,
 	}
 	counter := newRetainedNodeCounter(100)
 	inspection, ok := prepareInspectionHistory(resolved, counter)
diff --git a/internal/engine/history_inheritance.go b/internal/engine/history_inheritance.go
index 70c2001..db1ac55 100644
--- a/internal/engine/history_inheritance.go
+++ b/internal/engine/history_inheritance.go
@@ -281,32 +281,3 @@ func resolveInheritanceAttribution(operation inheritanceOperation, destination P
 	}
 	return selections
 }
-
-func operationPathForQuery(root, query Path) Path {
-	if pathContains(query, root) {
-		return root
-	}
-	return query
-}
-
-func inheritanceChangesForQuery(query Path, operation inheritanceOperation) []Change {
-	if operation.control != nil {
-		for _, selection := range resolveInheritanceAttribution(operation, query) {
-			return []Change{{Path: selection.path.clone(), Origin: cloneOrigin(selection.origin), Dependencies: clonePaths(selection.dependencies)}}
-		}
-		return nil
-	}
-	if operation.transfer == nil {
-		return nil
-	}
-	path := operationPathForQuery(operation.transfer.to, query)
-	selections := resolveInheritanceAttribution(operation, path)
-	changes := make([]Change, 0, len(selections))
-	for _, selection := range selections {
-		if selection.kind == inheritanceEvidenceDisplaced {
-			continue
-		}
-		changes = append(changes, Change{Path: selection.path.clone(), Origin: cloneOrigin(selection.origin), Dependencies: clonePaths(selection.dependencies)})
-	}
-	return changes
-}
diff --git a/internal/engine/history_inheritance_test.go b/internal/engine/history_inheritance_test.go
index 56bcfc7..87edac8 100644
--- a/internal/engine/history_inheritance_test.go
+++ b/internal/engine/history_inheritance_test.go
@@ -63,9 +63,6 @@ func TestInheritanceEvidenceUsesOrderedPayloadAndConcreteTransferShapes(t *testi
 		displaced[0].attribution.origin.Locations[0].SourceID != "child" {
 		t.Fatalf("pre-transfer child shape was not retained: %#v", displaced)
 	}
-	if public := projectedInheritanceChanges(displacedPath, model.inheritancePayloads[0].operations[1]); len(public) != 0 {
-		t.Fatalf("displaced child path unexpectedly projected publicly: %#v", public)
-	}
 	if builder.scratch != nil {
 		t.Fatal("frozen builder unexpectedly retained scratch")
 	}
@@ -74,31 +71,41 @@ func TestInheritanceEvidenceUsesOrderedPayloadAndConcreteTransferShapes(t *testi
 	}
 }
 
-func TestInheritanceResolverSharesProjectionAttribution(t *testing.T) {
+func TestInheritanceModelSharesProjectionAttribution(t *testing.T) {
 	t.Parallel()
 
 	from, to, reference := Keys("parents", "base"), Keys("children", "item"), Keys("parents", "base")
 	path := to.Key("nested").Key("value")
 	parent := Origin{Layer: LayerBase, Locations: []Location{{SourceID: "base"}}}
 	child := Origin{Layer: LayerOverlay, Locations: []Location{{SourceID: "child"}}}
+	parentDocument := parseDocumentForDecode(t, "nested: {value: parent}\n")
+	effectiveDocument := parseDocumentForDecode(t, "nested: {value: child}\n")
 	operation := inheritanceOperation{
 		transfer:         &inheritanceTransfer{from: from, to: to, reference: reference},
+		parent:           parentDocument,
+		effective:        effectiveDocument,
 		parentOrigins:    map[string]Origin{from.Key("nested").Key("value").String(): parent},
 		effectiveOrigins: map[string]Origin{path.String(): child},
 	}
-	selections := resolveInheritanceAttribution(operation, path)
-	if len(selections) != 2 || selections[0].kind != inheritanceEvidenceParent || selections[1].kind != inheritanceEvidenceChild {
-		t.Fatalf("shared resolver selections = %#v", selections)
+	root := parseDocumentForDecode(t, "children: {item: {nested: {value: old}}}\n")
+	builder := newHistoryBuilder()
+	builder.setScratch(root)
+	builder.observeInheritanceEvidence([]inheritanceOperation{operation})
+	model := builder.freeze()
+	selections := model.selectHistory(path)
+	if len(selections) != 2 || selections[0].role != historyRoleOperation || selections[1].role != historyRoleOperation {
+		t.Fatalf("model inheritance selections = %#v", selections)
 	}
-	if selections[0].path.String() != selections[1].path.String() || selections[0].origin.Operation != ChangeInheritance || selections[1].origin.Operation != ChangeInheritance {
-		t.Fatalf("parent and child attributions did not share one resolver: %#v", selections)
+	if selections[0].reportedPath.String() != to.String() || selections[1].reportedPath.String() != to.String() ||
+		selections[0].attribution.origin.Operation != ChangeInheritance || selections[1].attribution.origin.Operation != ChangeInheritance {
+		t.Fatalf("parent and child attributions did not share the model owner: %#v", selections)
 	}
-	changes := projectedInheritanceChanges(path, operation)
-	if len(changes) != 2 || changes[0].Origin.Locations[0].SourceID != selections[0].origin.Locations[0].SourceID ||
-		changes[1].Origin.Locations[0].SourceID != selections[1].origin.Locations[0].SourceID ||
-		changes[0].Dependencies[0].String() != from.String() || changes[0].Dependencies[1].String() != reference.String() ||
-		changes[1].Dependencies[0].String() != reference.String() {
-		t.Fatalf("metadata projection attribution = %#v; resolver = %#v", changes, selections)
+	if selections[0].attribution.origin.Locations[0].SourceID != "base" ||
+		selections[1].attribution.origin.Locations[0].SourceID != "child" ||
+		len(selections[0].attribution.dependencies) != 2 || selections[0].attribution.dependencies[0].String() != from.String() ||
+		selections[0].attribution.dependencies[1].String() != reference.String() ||
+		len(selections[1].attribution.dependencies) != 1 || selections[1].attribution.dependencies[0].String() != reference.String() {
+		t.Fatalf("model attribution dependencies or origins differ: %#v", selections)
 	}
 }
 
diff --git a/internal/engine/history_resolution_test.go b/internal/engine/history_resolution_test.go
index be0a972..7049b77 100644
--- a/internal/engine/history_resolution_test.go
+++ b/internal/engine/history_resolution_test.go
@@ -124,7 +124,14 @@ func TestMetadataFinalizationRegistersResolutionInventoryAndRoots(t *testing.T)
 
 	var metadata Metadata
 	snapshots := []resolutionSnapshot{parentSnapshot, snapshot}
-	finalizeMetadataPathsWithResolution(&metadata, final, nil, snapshots, before, before)
+	builder := newHistoryBuilder()
+	builder.setScratch(before)
+	builder.observeDocument(before, historyPhaseBaseline)
+	builder.observeDocument(final, historyPhasePostCLI)
+	builder.prefixReady = true
+	builder.observeResolutionEvidence(snapshots)
+	metadata.historyBuilder = builder
+	freezeMetadataHistory(&metadata, final)
 	if got := metadata.HistoricalPaths(); len(got) != 3 || got[0].String() != "" || got[1].String() != "/shape" || got[2].String() != "/shape/0" {
 		t.Fatalf("historical paths = %#v", got)
 	}
diff --git a/internal/engine/history_sequence_test.go b/internal/engine/history_sequence_test.go
index ad2f6ce..7dd09ef 100644
--- a/internal/engine/history_sequence_test.go
+++ b/internal/engine/history_sequence_test.go
@@ -272,19 +272,18 @@ func TestProjectedSequenceHistoryAgreesAcrossMetadataAndExplanation(t *testing.T
 		t.Fatalf("compose diagnostics = %#v", diagnostics)
 	}
 	path := Keys("records").Index(1).Key("token")
-	var metadata Metadata
-	finalizeMetadataPaths(&metadata, composed.root, composed.applications)
+	baseline := &document.Node{Kind: document.Mapping}
+	model := sourceHistoryModelForInspection(baseline, composed.root, composed.origins, composed.applications, composed.overlays)
+	metadata := Metadata{historyModel: model}
+	finalizeEffectiveMetadataPaths(&metadata, composed.root)
 	if !metadata.hasHistoricalPath(path) {
 		t.Fatalf("projected metadata omitted shifted path %s: %#v", path, metadata.HistoricalPaths())
 	}
 
-	baseline := &document.Node{Kind: document.Mapping}
-	model := sourceHistoryModelForInspection(baseline, composed.root, composed.origins, composed.applications, composed.overlays)
-	metadata.historyModel = model
 	inspection := &Inspection{metadata: metadata, history: model, final: composed.root}
 	inspection.secrets = classifySecretPaths(nil, func(candidate Path) bool {
 		return reflect.DeepEqual(candidate, path)
-	}, metadata, composed.root, nil)
+	}, metadata)
 	explanation, ok := inspection.Explain(path)
 	if !ok || !explanation.Effective.Redacted {
 		t.Fatalf("shifted explanation = %#v, %v", explanation, ok)
@@ -323,15 +322,14 @@ func TestReplacedProjectedSensitiveRecordRemainsRedacted(t *testing.T) {
 	})
 	final := applications[len(applications)-1].value
 	path := Keys("records").Index(1).Key("token")
-	var metadata Metadata
-	finalizeMetadataPaths(&metadata, final, applications)
 	baseline := &document.Node{Kind: document.Mapping}
 	model := sourceHistoryModelForInspection(baseline, final, nil, applications, nil)
-	metadata.historyModel = model
+	metadata := Metadata{historyModel: model}
+	finalizeEffectiveMetadataPaths(&metadata, final)
 	inspection := &Inspection{metadata: metadata, history: model, final: final}
 	inspection.secrets = classifySecretPaths(nil, func(candidate Path) bool {
 		return reflect.DeepEqual(candidate, path)
-	}, metadata, final, nil)
+	}, metadata)
 	explanation, ok := inspection.Explain(path)
 	if !ok || explanation.Effective.Present {
 		t.Fatalf("replaced shifted record explanation = %#v, %v", explanation, ok)
@@ -404,14 +402,13 @@ func TestMappedUpsertProjectsSensitiveReplacementEvidence(t *testing.T) {
 	finalRecords, _ := documentAtPath(finalRoot, Keys("records"))
 	finalRecords.Sequence = document.Clone(combined.value).Sequence
 
-	var metadata Metadata
-	finalizeMetadataPaths(&metadata, finalRoot, applications)
 	baseline := &document.Node{Kind: document.Mapping}
 	model := sourceHistoryModelForInspection(baseline, finalRoot, nil, applications, nil)
-	metadata.historyModel = model
+	metadata := Metadata{historyModel: model}
+	finalizeEffectiveMetadataPaths(&metadata, finalRoot)
 	inspection := &Inspection{metadata: metadata, history: model, final: finalRoot}
 	secretRule := func(candidate Path) bool { return reflect.DeepEqual(candidate, secretPath) }
-	inspection.secrets = classifySecretPaths(nil, secretRule, metadata, finalRoot, nil)
+	inspection.secrets = classifySecretPaths(nil, secretRule, metadata)
 	explanation, ok := inspection.Explain(secretPath)
 	if !ok || !explanation.Effective.Redacted {
 		t.Fatalf("mapped replacement explanation = %#v, %v", explanation, ok)
diff --git a/internal/engine/inheritance_history.go b/internal/engine/inheritance_history.go
index b4b21ed..3704f5e 100644
--- a/internal/engine/inheritance_history.go
+++ b/internal/engine/inheritance_history.go
@@ -1,63 +1,6 @@
 package engine
 
-import (
-	"slices"
-
-	"gitea.maximumdirect.net/eric/ConfigKit/internal/document"
-)
-
-// Retain source history at original paths. Structural operations are held once
-// per relationship and projected onto a requested destination path only when
-// History or Explain is queried.
-func applyInheritanceMetadata(metadata *Metadata, raw *document.Node, rawOrigins map[string]Origin, overlays []overlayRecord, expansion *inheritanceScope) {
-	if metadata == nil || expansion == nil {
-		return
-	}
-	sourceView := Metadata{
-		fields:  make(map[string]FieldInfo),
-		history: metadata.history,
-	}
-	walkDocument(raw, Path{}, func(path Path, node *document.Node) {
-		origin, found := rawOrigins[path.String()]
-		if !found {
-			origin = Origin{Layer: LayerBase, Locations: []Location{publicLocation(node.Location)}}
-		}
-		sourceView.fields[path.String()] = FieldInfo{Explicit: true, Null: node.Kind == document.Null, Origin: cloneOrigin(origin)}
-	})
-	applyOverlayMetadata(&sourceView, overlays)
-	metadata.history = sourceView.history
-}
-
-func historyWithInheritance(path Path, stored []Change, operations []inheritanceOperation) []Change {
-	split := len(stored)
-	for index, change := range stored {
-		if change.Origin.Layer == LayerCLI || change.Origin.Layer == LayerResolution {
-			split = index
-			break
-		}
-	}
-	history := cloneChanges(stored[:split])
-	for _, operation := range operations {
-		for _, change := range projectedInheritanceChanges(path, operation) {
-			if len(history) != 0 {
-				change.Previous = []Origin{cloneOrigin(history[len(history)-1].Origin)}
-			}
-			history = append(history, change)
-		}
-	}
-	for _, change := range stored[split:] {
-		cloned := cloneChange(change)
-		if len(history) != 0 {
-			cloned.Previous = []Origin{cloneOrigin(history[len(history)-1].Origin)}
-		}
-		history = append(history, cloned)
-	}
-	return history
-}
-
-func projectedInheritanceChanges(query Path, operation inheritanceOperation) []Change {
-	return inheritanceChangesForQuery(query, operation)
-}
+import "slices"
 
 func transferredOperationOrigin(operation inheritanceOperation, destination Path) (Origin, bool) {
 	if inheritanceOperationIdentity(operation, destination) {
diff --git a/internal/engine/inheritance_history_test.go b/internal/engine/inheritance_history_test.go
index ed8a150..c8c1ae1 100644
--- a/internal/engine/inheritance_history_test.go
+++ b/internal/engine/inheritance_history_test.go
@@ -125,9 +125,11 @@ func inheritanceInspectionFromComposition(t *testing.T, composed *composedDocume
 	metadata := metadataFromDecoded(decoded)
 	metadata.historyBuilder.setScratch(composed.root)
 	metadata.historyBuilder.observeSourceEvidence(composed.root, composed.origins, composed.applications, composed.overlays)
-	applyInheritanceMetadata(&metadata, composed.root, composed.origins, composed.overlays, expanded)
 	metadata.historyBuilder.setScratch(composed.root)
 	metadata.historyBuilder.observeInheritanceEvidence(expanded.operations)
+	metadata.historyBuilder.observePreCLICheckpoint(expanded.root, expanded.origins)
+	metadata.historyBuilder.observePostCLICheckpoint(expanded.root, expanded.origins)
+	metadata.historyBuilder.prefixReady = true
 	final := expanded.root
 	if len(snapshots) != 0 {
 		final = document.Clone(expanded.root)
@@ -137,7 +139,10 @@ func inheritanceInspectionFromComposition(t *testing.T, composed *composedDocume
 			}
 		}
 	}
-	finalizeMetadataPathsWithResolution(&metadata, final, composed.applications, snapshots, baseline, composed.root, expanded.root)
+	if len(snapshots) != 0 {
+		metadata.historyBuilder.observeResolutionEvidence(snapshots)
+	}
+	freezeMetadataHistory(&metadata, final)
 	return &Inspection{
 		metadata: metadata, history: metadata.historyModel, final: final,
 	}, expanded
diff --git a/internal/engine/inheritance_secret_test.go b/internal/engine/inheritance_secret_test.go
index b85a0e4..f5b8aa2 100644
--- a/internal/engine/inheritance_secret_test.go
+++ b/internal/engine/inheritance_secret_test.go
@@ -15,7 +15,7 @@ func TestInheritanceSensitivityFollowsCopiesWithoutMaskingNeighbors(t *testing.T
 			inspection, _ := inheritanceInspectionForTest(t, input)
 			inspection.secrets = classifySecretPaths(nil, func(path Path) bool {
 				return path.String() == classified.String()
-			}, inspection.metadata, inspection.final, nil)
+			}, inspection.metadata)
 			for _, path := range []Path{Keys("parent", "token"), Keys("child", "token"), Keys("next", "token"), Keys("other", "token")} {
 				explanation, found := inspection.Explain(path)
 				if !found || !explanation.Effective.Redacted || strings.Contains(explanation.Effective.YAML, canary) {
@@ -44,7 +44,7 @@ func TestInheritanceSensitivityPreservesDisplacedHistoryAndControl(t *testing.T)
 	inspection, _ := inheritanceInspectionForTest(t, parseCompositionDocument(t, "source-1", "parent: {branch: {token: "+canary+"}}\nchild: {extends: parent, branch: public}\n"))
 	inspection.secrets = classifySecretPaths(nil, func(path Path) bool {
 		return path.String() == Keys("parent", "branch", "token").String() || path.String() == Keys("child", inheritanceKey).String()
-	}, inspection.metadata, inspection.final, nil)
+	}, inspection.metadata)
 	path := Keys("child", "branch", "token")
 	explanation, found := inspection.Explain(path)
 	if !found || explanation.Effective.Present {
@@ -85,7 +85,7 @@ func TestInheritanceSensitivityIncludesSchemaTaggedSource(t *testing.T) {
 		t.Fatal(issue)
 	}
 	inspection, _ := inheritanceInspectionForTest(t, parseCompositionDocument(t, "source-1", "parent: {token: TAGGED-CANARY}\nchild: {extends: parent}\n"))
-	inspection.secrets = classifySecretPaths(schema, nil, inspection.metadata, inspection.final, nil)
+	inspection.secrets = classifySecretPaths(schema, nil, inspection.metadata)
 	child, found := inspection.Explain(Keys("child", "token"))
 	if !found || !child.Effective.Redacted || strings.Contains(child.Effective.YAML, "TAGGED-CANARY") {
 		t.Fatalf("tagged source copy = %#v, %v", child, found)
@@ -104,7 +104,7 @@ func TestSourceVersionEvidenceSensitivityFollowsInheritanceAndDisplacedHistory(t
 	}
 	inspection.secrets = classifySecretPathsWithEvidence(nil, func(path Path) bool {
 		return path.String() == secretPath.String()
-	}, inspection.metadata, inspection.final, nil, []*sourceVersionEvidence{evidence})
+	}, inspection.metadata, []*sourceVersionEvidence{evidence})
 
 	path := Keys("child", "branch", "token")
 	explanation, found := inspection.Explain(path)
@@ -162,7 +162,7 @@ func TestInheritedSecretReferencesResolveOnlyAfterExpansion(t *testing.T) {
 		t.Fatalf("inherited reference resolution = %#v, %d", resolved.diagnostics, lookupCount)
 	}
 	inspection, _ := inheritanceInspectionFromComposition(t, composed)
-	inspection.secrets = classifySecretPaths(schema, nil, inspection.metadata, inspection.final, nil)
+	inspection.secrets = classifySecretPaths(schema, nil, inspection.metadata)
 	var rendered bytes.Buffer
 	if err := inspection.WriteEffective(&rendered); err != nil || strings.Contains(rendered.String(), "RESOLVED-CREDENTIAL-CANARY") {
 		t.Fatalf("reference rendering = %q, %v", rendered.String(), err)
diff --git a/internal/engine/load_metadata.go b/internal/engine/load_metadata.go
index 0266ce8..4a87bda 100644
--- a/internal/engine/load_metadata.go
+++ b/internal/engine/load_metadata.go
@@ -60,108 +60,13 @@ func (input resolutionInput) sourceContext(id string) (ResourceContext, bool) {
 func metadataFromDecoded(decoded decodedConfiguration) Metadata {
 	metadata := Metadata{
 		fields:         make(map[string]FieldInfo),
-		history:        make(map[string][]Change),
 		historyBuilder: newHistoryBuilder(),
 	}
 	metadata.historyBuilder.observeBaseline(decoded.baseline)
-	baseline := make(map[string]*document.Node)
-	indexDocument(decoded.baseline, Path{}, baseline)
-	for pointer := range baseline {
-		path, err := ParsePath(pointer)
-		if err != nil {
-			continue
-		}
-		metadata.history[pointer] = append(metadata.history[pointer], Change{
-			Path: path, Origin: Origin{Layer: LayerDefault},
-		})
-	}
-	for pointer := range decoded.presence {
-		path, err := ParsePath(pointer)
-		if err != nil {
-			continue
-		}
-		origin := cloneOrigin(decoded.origins[pointer])
-		change := Change{Path: path, Origin: origin}
-		if _, ok := baseline[pointer]; ok {
-			change.Previous = []Origin{{Layer: LayerDefault}}
-		}
-		metadata.history[pointer] = append(metadata.history[pointer], change)
-	}
 	collectFieldInfo(decoded.final, Path{}, decoded, metadata.fields)
 	return metadata
 }
 
-func applyOverlayMetadata(metadata *Metadata, records []overlayRecord) {
-	baseline := make(map[string][]Change, len(metadata.history))
-	for pointer, history := range metadata.history {
-		for _, change := range history {
-			if change.Origin.Layer == LayerDefault {
-				baseline[pointer] = append(baseline[pointer], cloneChange(change))
-			}
-		}
-	}
-	events := make(map[string][]Change)
-	for _, record := range records {
-		exact := false
-		for _, displaced := range record.displaced {
-			pointer := displaced.path.String()
-			appendInputOriginEvent(events, baseline, pointer, displaced.path, displaced.origin)
-			appendInputChangeEvent(events, baseline, pointer, record.change)
-			if pointer == record.change.Path.String() {
-				exact = true
-			}
-		}
-		if !exact {
-			pointer := record.change.Path.String()
-			for _, previous := range record.change.Previous {
-				appendInputOriginEvent(events, baseline, pointer, record.change.Path, previous)
-			}
-			appendInputChangeEvent(events, baseline, pointer, record.change)
-		}
-	}
-	for pointer, info := range metadata.fields {
-		if !info.Explicit {
-			continue
-		}
-		path, err := ParsePath(pointer)
-		if err != nil {
-			continue
-		}
-		appendInputOriginEvent(events, baseline, pointer, path, info.Origin)
-	}
-	metadata.history = make(map[string][]Change, len(baseline)+len(events))
-	for pointer, history := range baseline {
-		metadata.history[pointer] = cloneChanges(history)
-	}
-	for pointer, history := range events {
-		metadata.history[pointer] = append(metadata.history[pointer], cloneChanges(history)...)
-	}
-}
-
-func appendInputOriginEvent(events map[string][]Change, baseline map[string][]Change, pointer string, path Path, origin Origin) {
-	if origin.Layer == "" {
-		return
-	}
-	history := events[pointer]
-	if len(history) != 0 && originRepresentedByChange(path, origin, history[len(history)-1]) {
-		return
-	}
-	appendInputChangeEvent(events, baseline, pointer, Change{Path: path.clone(), Origin: cloneOrigin(origin)})
-}
-
-func appendInputChangeEvent(events map[string][]Change, baseline map[string][]Change, pointer string, value Change) {
-	change := cloneChange(value)
-	history := events[pointer]
-	if len(history) != 0 {
-		change.Previous = []Origin{cloneOrigin(history[len(history)-1].Origin)}
-	} else if defaults := baseline[pointer]; len(defaults) != 0 {
-		change.Previous = []Origin{cloneOrigin(defaults[len(defaults)-1].Origin)}
-	} else {
-		change.Previous = nil
-	}
-	events[pointer] = append(history, change)
-}
-
 func originContainedBy(candidate, container Origin) bool {
 	if candidate.Layer != container.Layer || candidate.Operation != container.Operation {
 		return false
@@ -195,14 +100,6 @@ func originContainedBy(candidate, container Origin) bool {
 	return true
 }
 
-func cloneChanges(changes []Change) []Change {
-	cloned := make([]Change, len(changes))
-	for index, change := range changes {
-		cloned[index] = cloneChange(change)
-	}
-	return cloned
-}
-
 func collectFieldInfo(node *document.Node, path Path, decoded decodedConfiguration, fields map[string]FieldInfo) {
 	pointer := path.String()
 	_, explicit := decoded.presence[pointer]
@@ -224,13 +121,11 @@ func collectFieldInfo(node *document.Node, path Path, decoded decodedConfigurati
 }
 
 func cloneMetadata(metadata Metadata) Metadata {
-	if metadata.fields == nil && metadata.history == nil && metadata.historyModel == nil {
+	if metadata.fields == nil && metadata.historyModel == nil {
 		return Metadata{}
 	}
 	cloned := Metadata{
 		fields:       make(map[string]FieldInfo, len(metadata.fields)),
-		history:      make(map[string][]Change, len(metadata.history)),
-		inheritance:  append([]inheritanceOperation(nil), metadata.inheritance...),
 		historyModel: metadata.historyModel,
 	}
 	cloned.effectivePaths = make(map[string]Path, len(metadata.effectivePaths))
@@ -240,13 +135,6 @@ func cloneMetadata(metadata Metadata) Metadata {
 	for path, info := range metadata.fields {
 		cloned.fields[path] = cloneFieldInfo(info)
 	}
-	for path, changes := range metadata.history {
-		clonedChanges := make([]Change, len(changes))
-		for index, change := range changes {
-			clonedChanges[index] = cloneChange(change)
-		}
-		cloned.history[path] = clonedChanges
-	}
 	return cloned
 }
 
@@ -268,56 +156,16 @@ func applyResolutionMetadata(metadata *Metadata, resolved resolutionResult, entr
 
 	for snapshotID, snapshot := range resolved.snapshots {
 		pointer := snapshotPointers[snapshotID]
-		change := cloneChange(snapshot.change)
 		if info, ok := metadata.fields[pointer]; ok {
-			change.Previous = []Origin{cloneOrigin(info.Origin)}
-			info.Origin = cloneOrigin(change.Origin)
+			info.Origin = cloneOrigin(snapshot.change.Origin)
 			metadata.fields[pointer] = info
 		}
-		metadata.history[pointer] = append(metadata.history[pointer], change)
 	}
 
-	appendResolutionDescendantHistory(metadata, resolved.snapshots, snapshotPointers, finalPaths, &deltaCoverage, snapshotIDs)
 	applyResolutionFieldOrigins(metadata.fields, resolved.snapshots, &deltaCoverage, snapshotIDs)
 	refreshResolutionFields(metadata.fields, finalPaths, resolved.final, entry, resolved.snapshots, snapshotCoverage)
 }
 
-func appendResolutionDescendantHistory(metadata *Metadata, snapshots []resolutionSnapshot, snapshotPointers []string, finalPaths map[string]*document.Node, deltaIndex *pathPrefixIndex, snapshotIDs []int) {
-	allPointers := make(map[string]struct{}, len(metadata.history)+len(finalPaths))
-	for pointer := range metadata.history {
-		if _, err := ParsePath(pointer); err == nil {
-			allPointers[pointer] = struct{}{}
-		}
-	}
-	for pointer := range finalPaths {
-		allPointers[pointer] = struct{}{}
-	}
-	buckets := make([][]string, len(snapshotIDs))
-	for pointer := range allPointers {
-		deltaIndex.visitAncestors(pointer, func(deltaID int) {
-			snapshotID := snapshotIDs[deltaID]
-			if snapshotID < 0 || pointer == snapshotPointers[snapshotID] {
-				return
-			}
-			buckets[deltaID] = append(buckets[deltaID], pointer)
-		})
-	}
-	for deltaID, pointers := range buckets {
-		snapshotID := snapshotIDs[deltaID]
-		if snapshotID < 0 {
-			continue
-		}
-		slices.Sort(pointers)
-		for _, pointer := range pointers {
-			change := cloneChange(snapshots[snapshotID].change)
-			if info, ok := metadata.fields[pointer]; ok {
-				change.Previous = []Origin{cloneOrigin(info.Origin)}
-			}
-			metadata.history[pointer] = append(metadata.history[pointer], change)
-		}
-	}
-}
-
 func applyResolutionFieldOrigins(fields map[string]FieldInfo, snapshots []resolutionSnapshot, deltaIndex *pathPrefixIndex, snapshotIDs []int) {
 	buckets := make([][]string, len(snapshotIDs))
 	for pointer := range fields {
diff --git a/internal/engine/load_result.go b/internal/engine/load_result.go
index bde5827..358e312 100644
--- a/internal/engine/load_result.go
+++ b/internal/engine/load_result.go
@@ -10,19 +10,10 @@ import (
 // it owns no source access, options, or long-lived schema state.
 type resolvedLoad[T any] struct {
 	configuration   T
-	decoded         decodedConfiguration
 	metadata        Metadata
-	historyBuilder  *historyBuilder
 	final           *document.Node
-	snapshots       []resolutionSnapshot
-	applications    []historyApplication
-	postDecodeApps  []historyApplication
-	structuralInput *document.Node
-	preCLI          *document.Node
-	preCLIOrigins   map[string]Origin
 	referenceInput  *document.Node
 	versionEvidence []*sourceVersionEvidence
-	inheritance     *inheritanceScope
 	contexts        map[string]ResourceContext
 }
 
@@ -57,10 +48,7 @@ func resolveLoadInput[T any](schema *schemaDescriptor, definition Definition[T],
 	decoded := prepared.decoded
 	configuration := decoded.value.Interface().(T)
 	metadata := prepared.metadata
-	builder := prepared.historyBuilder
-	if builder == nil {
-		builder = metadata.historyBuilder
-	}
+	builder := metadata.historyBuilder
 	final := decoded.final
 	referenceInput := prepared.referenceInput
 	var resolutionSnapshots []resolutionSnapshot
@@ -86,22 +74,13 @@ func resolveLoadInput[T any](schema *schemaDescriptor, definition Definition[T],
 	if refreshReferenceInput {
 		referenceInput = documentWithMetadataLocations(final, metadata, input.document)
 	}
-	applications := []historyApplication(nil)
-	if input.composition != nil {
-		applications = input.composition.applications
-	} else if input.document != nil {
-		applications = []historyApplication{{layer: LayerBase, value: input.document}}
-	}
 	var versionEvidence []*sourceVersionEvidence
 	if input.versionState != nil {
 		versionEvidence = append(versionEvidence, input.versionState.evidence...)
 	}
 	return resolvedLoad[T]{
-		configuration: configuration, decoded: decoded, metadata: metadata, historyBuilder: builder, final: final,
-		snapshots: resolutionSnapshots, applications: applications,
-		postDecodeApps: prepared.postDecodeApps, structuralInput: document.Clone(prepared.structuralInput),
-		preCLI: prepared.preCLI, preCLIOrigins: prepared.preCLIOrigins, referenceInput: referenceInput,
-		versionEvidence: versionEvidence, inheritance: input.inheritance, contexts: input.contexts,
+		configuration: configuration, metadata: metadata, final: final, referenceInput: referenceInput,
+		versionEvidence: versionEvidence, contexts: input.contexts,
 	}, diagnostics
 }
 
@@ -117,21 +96,7 @@ func detachLoadConfiguration[T any](schema *schemaDescriptor, configuration T, m
 
 func prepareInspectionHistory[T any](resolved resolvedLoad[T], counter *retainedNodeCounter) (*Inspection, bool) {
 	metadata := resolved.metadata
-	if resolved.historyBuilder != nil {
-		metadata.historyBuilder = resolved.historyBuilder
-	} else if resolved.inheritance != nil {
-		builder := newHistoryBuilder()
-		if resolved.decoded.baseline != nil {
-			builder.observeBaseline(resolved.decoded.baseline)
-		}
-		builder.setScratch(resolved.final)
-		builder.observeInheritanceEvidence(resolved.inheritance.operations)
-		metadata.historyBuilder = builder
-	}
-	finalizeMetadataPathsWithResolution(
-		&metadata, resolved.final, resolved.applications, resolved.snapshots,
-		resolved.decoded.baseline, resolved.structuralInput, resolved.preCLI, resolved.decoded.final,
-	)
+	freezeMetadataHistory(&metadata, resolved.final)
 	model := metadata.historyModel
 	inspection := &Inspection{
 		metadata: metadata,
@@ -152,8 +117,8 @@ func publishLoadResult[T any](schema *schemaDescriptor, definition Definition[T]
 		accumulator.add(*issue)
 		return nil, accumulator.loadError()
 	}
-	metadata, final := inspection.metadata, inspection.final
-	secrets := classifySecretPathsWithEvidence(schema, definition.Secret, metadata, final, nil, resolved.versionEvidence)
+	metadata := inspection.metadata
+	secrets := classifySecretPathsWithEvidence(schema, definition.Secret, metadata, resolved.versionEvidence)
 	sources := sourceInfosWithVersionEvidence(accumulator.sources, resolved.versionEvidence, secrets, false)
 	inspection.metadata = metadata
 	inspection.sources = sources
diff --git a/internal/engine/metadata.go b/internal/engine/metadata.go
index bb7a074..c675c22 100644
--- a/internal/engine/metadata.go
+++ b/internal/engine/metadata.go
@@ -7,22 +7,10 @@ import "gitea.maximumdirect.net/eric/ConfigKit/internal/document"
 type Metadata struct {
 	effectivePaths map[string]Path
 	fields         map[string]FieldInfo
-	history        map[string][]Change
-	inheritance    []inheritanceOperation
 	historyBuilder *historyBuilder
 	historyModel   *historyModel
 }
 
-func (m Metadata) currentHistoryModel() *historyModel {
-	if m.historyModel != nil {
-		return m.historyModel
-	}
-	if m.historyBuilder != nil {
-		return m.historyBuilder.model
-	}
-	return nil
-}
-
 // Lookup returns information for an effective path. Unknown and invalid paths
 // return false.
 func (m Metadata) Lookup(path Path) (FieldInfo, bool) {
@@ -155,80 +143,13 @@ func (m Metadata) hasHistoricalPath(path Path) bool {
 	return m.historyEvidence().hasObservedShape(path)
 }
 
-func finalizeMetadataPaths(m *Metadata, final *document.Node, applications []historyApplication, earlier ...*document.Node) {
-	finalizeMetadataPathsWithResolution(m, final, applications, nil, earlier...)
-}
-
-func finalizeMetadataPathsWithResolution(m *Metadata, final *document.Node, applications []historyApplication, snapshots []resolutionSnapshot, earlier ...*document.Node) {
+func freezeMetadataHistory(m *Metadata, final *document.Node) {
 	finalizeEffectiveMetadataPaths(m, final)
 	builder := m.historyBuilder
-	if builder != nil && builder.prefixReady {
-		if len(snapshots) != 0 && builder.model.resolutionPayload == nil {
-			if len(earlier) != 0 {
-				builder.setScratch(earlier[len(earlier)-1])
-			}
-			builder.observeResolutionEvidence(snapshots)
-		}
-		if builder.model.final != final {
-			builder.model.final = final
-		}
-		m.historyModel = builder.freeze()
-		m.historyBuilder = nil
-		return
-	}
-	if builder == nil {
-		builder = newHistoryBuilder()
-	}
-	if len(earlier) != 0 {
-		builder.model.baseline = earlier[0]
+	if builder == nil || !builder.prefixReady {
+		panic("configkit: metadata history prefix is not ready")
 	}
 	builder.model.final = final
-	for index, tree := range earlier {
-		phase := historyPhaseSources
-		switch index {
-		case 0:
-			phase = historyPhaseBaseline
-		case 2:
-			phase = historyPhasePreCLI
-		case 3:
-			phase = historyPhasePostCLI
-		}
-		builder.observeDocument(tree, phase)
-	}
-	if final != nil {
-		builder.observeDocument(final, historyPhasePostCLI)
-	}
-	for _, application := range applications {
-		phase := historyPhaseSources
-		if application.layer == LayerCLI {
-			phase = historyPhaseCLI
-		}
-		payload := builder.nextPayload(phase)
-		walkHistoryApplication(application, func(_, effective Path, node *document.Node) {
-			builder.addInventoryObservation(effective, effective, payload, phase, node.Sensitive)
-		})
-	}
-	for _, operation := range m.inheritance {
-		payload := builder.nextPayload(historyPhaseInheritance)
-		if operation.control != nil {
-			builder.addInventoryObservation(operation.control.path, operation.control.path, payload, historyPhaseInheritance, false)
-			continue
-		}
-		if operation.transfer == nil {
-			continue
-		}
-		for _, root := range []*document.Node{operation.parent, operation.effective} {
-			walkDocument(root, operation.transfer.to, func(path Path, node *document.Node) {
-				builder.addInventoryObservation(path, path, payload, historyPhaseInheritance, node.Sensitive)
-			})
-		}
-	}
-	if len(snapshots) != 0 {
-		if len(earlier) != 0 {
-			builder.setScratch(earlier[len(earlier)-1])
-		}
-		builder.observeResolutionEvidence(snapshots)
-	}
 	m.historyModel = builder.freeze()
 	m.historyBuilder = nil
 }
diff --git a/internal/engine/metadata_test.go b/internal/engine/metadata_test.go
index 5ab8ef7..87361fc 100644
--- a/internal/engine/metadata_test.go
+++ b/internal/engine/metadata_test.go
@@ -47,12 +47,16 @@ func TestMetadataHistoricalPaths(t *testing.T) {
 	}
 }
 
-func TestMetadataPathIndexesOwnIndependentSegments(t *testing.T) {
+func TestEffectivePathIndexOwnsIndependentSegments(t *testing.T) {
 	t.Parallel()
 
 	final := parseDocumentForDecode(t, "service: {workers: [1]}\n")
 	var metadata Metadata
-	finalizeMetadataPaths(&metadata, final, nil)
+	finalizeEffectiveMetadataPaths(&metadata, final)
+	builder := newHistoryBuilder()
+	builder.observePostCLICheckpoint(final, nil)
+	builder.model.final = final
+	metadata.historyModel = builder.freeze()
 	pointer := "/service/workers/0"
 	effective := metadata.effectivePaths[pointer]
 	historical := metadata.historyModel.concreteShapes(pointer)
@@ -75,9 +79,13 @@ func TestMetadataPathIndexesRetainDistinctHistoricalShapes(t *testing.T) {
 
 	final := parseDocumentForDecode(t, "shape: [replacement]\n")
 	earlier := parseDocumentForDecode(t, "shape: {'0': base}\n")
-	var metadata Metadata
-	// Repeated trees must not add duplicate shapes to the historical index.
-	finalizeMetadataPaths(&metadata, final, nil, earlier, earlier, final)
+	builder := newHistoryBuilder()
+	builder.observeBaseline(earlier)
+	builder.setScratch(earlier)
+	builder.observePostCLICheckpoint(final, nil)
+	builder.model.final = final
+	metadata := Metadata{historyModel: builder.freeze()}
+	finalizeEffectiveMetadataPaths(&metadata, final)
 	keyPath := Keys("shape", "0")
 	indexPath := Keys("shape").Index(0)
 	pointer := indexPath.String()
diff --git a/internal/engine/override_context.go b/internal/engine/override_context.go
index b221979..83f7f82 100644
--- a/internal/engine/override_context.go
+++ b/internal/engine/override_context.go
@@ -2,19 +2,13 @@ package engine
 
 import "gitea.maximumdirect.net/eric/ConfigKit/internal/document"
 
-// postDecodeOverrideContext keeps the structural, typed pre-CLI, and effective
-// post-CLI views distinct while preparing the existing inspection machinery.
+// postDecodeOverrideContext carries the typed post-CLI state and detached
+// resolution views after the history builder has taken ownership of evidence.
 type postDecodeOverrideContext struct {
-	structuralInput *document.Node
-	preCLI          *document.Node
-	preCLIOrigins   map[string]Origin
-	decoded         decodedConfiguration
-	metadata        Metadata
-	historyBuilder  *historyBuilder
-	resolution      resolutionInput
-	applications    []historyApplication
-	postDecodeApps  []historyApplication
-	referenceInput  *document.Node
+	decoded        decodedConfiguration
+	metadata       Metadata
+	resolution     resolutionInput
+	referenceInput *document.Node
 }
 
 func preparePostDecodeOverrideContext(input assembledInput, before decodedConfiguration, assigned decodedOverrideResult) postDecodeOverrideContext {
@@ -32,14 +26,12 @@ func preparePostDecodeOverrideContext(input assembledInput, before decodedConfig
 		structuralOverlays = input.composition.overlays
 		metadata.historyBuilder.setScratch(input.composition.root)
 		metadata.historyBuilder.observeSourceEvidence(input.composition.root, input.composition.origins, applications, structuralOverlays)
-		applyInheritanceMetadata(&metadata, input.composition.root, input.composition.origins, structuralOverlays, input.inheritance)
 		metadata.historyBuilder.setScratch(input.composition.root)
 		metadata.historyBuilder.observeInheritanceEvidence(input.inheritance.operations)
 	} else if input.composition != nil {
 		structuralOverlays = input.composition.overlays
 		metadata.historyBuilder.setScratch(input.composition.root)
 		metadata.historyBuilder.observeSourceEvidence(input.composition.root, input.composition.origins, applications, structuralOverlays)
-		applyOverlayMetadata(&metadata, structuralOverlays)
 	} else if len(applications) != 0 {
 		metadata.historyBuilder.observeSourceEvidence(input.document, nil, applications, nil)
 	}
@@ -58,7 +50,8 @@ func preparePostDecodeOverrideContext(input assembledInput, before decodedConfig
 		collectFieldInfo(after.final, Path{}, after, metadata.fields)
 	}
 	if len(cliRecords) != 0 || len(postDecodeApps) != 0 {
-		appendPostDecodeCLIHistory(&metadata, cliRecords, postDecodeApps, before.final)
+		metadata.historyBuilder.setScratch(before.final)
+		metadata.historyBuilder.observeCLIEvidence(postDecodeApps, cliRecords)
 	}
 	metadata.historyBuilder.observePostCLICheckpoint(after.final, after.origins)
 	metadata.historyBuilder.prefixReady = true
@@ -82,33 +75,10 @@ func preparePostDecodeOverrideContext(input assembledInput, before decodedConfig
 	finalizeEffectiveMetadataPaths(&metadata, assigned.final)
 
 	return postDecodeOverrideContext{
-		structuralInput: document.Clone(input.document),
-		preCLI:          document.Clone(before.final),
-		preCLIOrigins:   cloneOrigins(before.origins),
-		decoded:         after,
-		metadata:        metadata,
-		historyBuilder:  metadata.historyBuilder,
-		resolution:      resolution,
-		applications:    applications,
-		postDecodeApps:  postDecodeApps,
-		referenceInput:  documentWithMetadataLocations(assigned.final, metadata, input.document),
-	}
-}
-
-// Source history is already assembled, with inheritance projected at query time.
-// Reuse overlay event construction for CLI changes without reapplying displaced
-// source definitions after those later assignments.
-func appendPostDecodeCLIHistory(metadata *Metadata, records []overlayRecord, applications []historyApplication, before *document.Node) {
-	metadata.historyBuilder.setScratch(before)
-	metadata.historyBuilder.observeCLIEvidence(applications, records)
-	cli := Metadata{fields: metadata.fields}
-	applyOverlayMetadata(&cli, records)
-	for pointer, history := range cli.history {
-		for _, change := range history {
-			if change.Origin.Layer == LayerCLI {
-				appendInputChangeEvent(metadata.history, nil, pointer, change)
-			}
-		}
+		decoded:        after,
+		metadata:       metadata,
+		resolution:     resolution,
+		referenceInput: documentWithMetadataLocations(assigned.final, metadata, input.document),
 	}
 }
 
@@ -169,19 +139,14 @@ func collectAffectedOverrideOrigins(displaced *[]displacedDefinition, existing,
 	}
 }
 
-func (context postDecodeOverrideContext) historyApplications() []historyApplication {
-	applications := cloneHistoryApplications(context.applications)
-	return append(applications, cloneHistoryApplications(context.postDecodeApps)...)
-}
-
 func structuralHistoryApplications(input assembledInput) []historyApplication {
 	if input.composition != nil {
-		return cloneHistoryApplications(input.composition.applications)
+		return input.composition.applications
 	}
 	if input.document == nil {
 		return nil
 	}
-	return []historyApplication{{layer: LayerBase, value: document.Clone(input.document)}}
+	return []historyApplication{{layer: LayerBase, value: input.document}}
 }
 
 // documentWithMetadataLocations attaches effective origin coordinates to a
@@ -289,7 +254,7 @@ func metadataFieldLocation(metadata Metadata, path Path, origin Origin) (documen
 	if location, ok := latestOriginDocumentLocation(origin); ok {
 		return location, true
 	}
-	if model := metadata.currentHistoryModel(); model != nil {
+	if model := metadata.historyEvidence(); model != nil {
 		location, ok := model.latestHistoricalLocation(path)
 		if ok {
 			return document.Location{SourceID: location.SourceID, Line: location.Line, Column: location.Column}, true
diff --git a/internal/engine/override_context_test.go b/internal/engine/override_context_test.go
index 7cc7e04..ce54f40 100644
--- a/internal/engine/override_context_test.go
+++ b/internal/engine/override_context_test.go
@@ -50,21 +50,14 @@ func TestPostDecodeOverrideContextOrdersDecodeCLIAndResolutionEvidence(t *testin
 		t.Fatalf("applyDecodedOverrides() issues = %#v", issues)
 	}
 	prepared := preparePostDecodeOverrideContext(input, decoded, assigned)
-	if prepared.historyBuilder == nil || prepared.historyBuilder != prepared.metadata.historyBuilder || !prepared.historyBuilder.prefixReady {
+	if prepared.metadata.historyBuilder == nil || !prepared.metadata.historyBuilder.prefixReady {
 		t.Fatal("post-decode handoff did not retain the completed history prefix")
 	}
 	if prepared.resolution.metadata.historyBuilder != nil || prepared.resolution.metadata.historyModel != nil {
 		t.Fatal("resolution entry view borrowed mutable or historical state")
 	}
-	if prepared.structuralInput == structural || prepared.preCLI == decoded.final ||
-		prepared.decoded.final == assigned.final || prepared.referenceInput == assigned.final {
-		t.Fatal("structural, pre-CLI, post-CLI, and located snapshots are not detached")
-	}
-	if raw, ok := documentAtPath(prepared.structuralInput, Keys("version")); !ok || raw.Kind != document.Number || raw.Text != "1" {
-		t.Fatalf("structural version = %#v", raw)
-	}
-	if typed, ok := documentAtPath(prepared.preCLI, Keys("version")); !ok || typed.Kind != document.String || typed.Text != "1" {
-		t.Fatalf("pre-CLI typed version = %#v", typed)
+	if prepared.decoded.final == assigned.final || prepared.referenceInput == assigned.final {
+		t.Fatal("post-CLI configuration and located resolution views are not detached")
 	}
 	if prepared.metadata.fields["/count"].Origin.Layer != LayerCLI || !prepared.metadata.fields["/count"].Explicit {
 		t.Fatalf("equal-value CLI metadata = %#v", prepared.metadata.fields["/count"])
@@ -75,9 +68,6 @@ func TestPostDecodeOverrideContextOrdersDecodeCLIAndResolutionEvidence(t *testin
 	if _, explicit := prepared.decoded.presence["/items/0/enabled"]; explicit {
 		t.Fatal("replaced list retained discarded-child presence")
 	}
-	if len(prepared.applications) != 1 || len(prepared.postDecodeApps) != len(batch.overrides) || len(prepared.historyApplications()) != 1+len(batch.overrides) {
-		t.Fatalf("history applications = structural:%d CLI:%d all:%d", len(prepared.applications), len(prepared.postDecodeApps), len(prepared.historyApplications()))
-	}
 	if prepared.resolution.contexts["source-1"].BaseDir != "/config" {
 		t.Fatalf("resolution source contexts = %#v", prepared.resolution.contexts)
 	}
@@ -101,8 +91,8 @@ func TestPostDecodeOverrideContextOrdersDecodeCLIAndResolutionEvidence(t *testin
 	if len(resolveDiagnostics) != 0 {
 		t.Fatalf("resolveLoadInput() diagnostics = %#v", resolveDiagnostics)
 	}
-	if resolvedContext.historyBuilder == nil || resolvedContext.historyBuilder != resolvedContext.metadata.historyBuilder ||
-		resolvedContext.historyBuilder.model.resolutionPayload == nil || len(resolvedContext.historyBuilder.model.resolutionPayload.snapshots) != 1 {
+	if resolvedContext.metadata.historyBuilder == nil || resolvedContext.metadata.historyBuilder.model.resolutionPayload == nil ||
+		len(resolvedContext.metadata.historyBuilder.model.resolutionPayload.snapshots) != 1 {
 		t.Fatal("resolution evidence was not appended once to the handed-off model")
 	}
 	if location, ok := metadataFieldLocation(resolvedContext.metadata, Keys("count"), Origin{Layer: LayerResolution}); !ok || location.SourceID != countSource {
@@ -115,7 +105,7 @@ func TestPostDecodeOverrideContextOrdersDecodeCLIAndResolutionEvidence(t *testin
 		t.Fatalf("post-resolution reference location = %#v, %v", value, ok)
 	}
 
-	finalizeMetadataPaths(&prepared.metadata, assigned.final, prepared.historyApplications(), decoded.baseline, prepared.structuralInput, prepared.preCLI, assigned.final)
+	freezeMetadataHistory(&prepared.metadata, assigned.final)
 	inspection := Inspection{
 		metadata: prepared.metadata, history: prepared.metadata.historyModel, final: assigned.final,
 	}
diff --git a/internal/engine/resolution_index_test.go b/internal/engine/resolution_index_test.go
index 711a204..23b449a 100644
--- a/internal/engine/resolution_index_test.go
+++ b/internal/engine/resolution_index_test.go
@@ -211,47 +211,51 @@ func TestApplyResolutionMetadataPreservesOverlappingDeltaOrder(t *testing.T) {
 	oldOrigin := Origin{Layer: LayerBase}
 	parentOrigin := Origin{Layer: LayerResolution, Operation: ChangeNormalization}
 	childOrigin := Origin{Layer: LayerResolution, Operation: ChangeDerivedDefault}
-	leaf := &document.Node{Kind: document.String, Text: "value"}
-	final := &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{
-		Key: "group",
-		Value: &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{
-			Key:   "item",
-			Value: &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{Key: "leaf", Value: leaf}}},
-		}}},
-	}}}
+	beforeLeaf := &document.Node{Kind: document.String, Text: "before"}
+	afterLeaf := &document.Node{Kind: document.String, Text: "after"}
+	beforeItem := &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{Key: "leaf", Value: beforeLeaf}}}
+	afterItem := &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{Key: "leaf", Value: afterLeaf}}}
+	beforeGroup := &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{Key: "item", Value: beforeItem}}}
+	afterGroup := &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{Key: "item", Value: afterItem}}}
+	before := &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{Key: "group", Value: beforeGroup}}}
+	final := &document.Node{Kind: document.Mapping, Mapping: []document.Entry{{Key: "group", Value: afterGroup}}}
+	path := Keys("group", "item", "leaf")
+	builder := newHistoryBuilder()
+	builder.setScratch(before)
+	snapshots := []resolutionSnapshot{
+		{change: Change{Path: Keys("group"), Origin: parentOrigin}, before: beforeGroup, after: afterGroup},
+		{change: Change{Path: Keys("group", "item"), Origin: childOrigin}, before: beforeItem, after: afterItem},
+	}
+	builder.observeResolutionEvidence(snapshots)
+	builder.model.final = final
 	metadata := &Metadata{
-		fields:  map[string]FieldInfo{"/group/item/leaf": {Origin: oldOrigin}},
-		history: make(map[string][]Change),
+		fields:         map[string]FieldInfo{path.String(): {Explicit: true, Origin: oldOrigin}},
+		historyBuilder: builder,
 	}
 	entry := resolutionInput{metadata: Metadata{
-		fields:         map[string]FieldInfo{"/group/item/leaf": {Explicit: true, Origin: oldOrigin}},
-		effectivePaths: effectivePathIndex(final),
+		fields:         map[string]FieldInfo{path.String(): {Explicit: true, Origin: oldOrigin}},
+		effectivePaths: effectivePathIndex(before),
 	}}
 	resolved := resolutionResult{
 		final:  final,
 		deltas: []documentDelta{{path: Keys("group")}, {path: Keys("group", "item")}},
-		snapshots: []resolutionSnapshot{
-			{change: Change{Path: Keys("group"), Origin: parentOrigin}},
-			{change: Change{Path: Keys("group", "item"), Origin: childOrigin}},
-		},
+		snapshots: snapshots,
 	}
 
 	applyResolutionMetadata(metadata, resolved, entry)
+	metadata.effectivePaths = effectivePathIndex(final)
+	metadata.historyModel = builder.freeze()
+	metadata.historyBuilder = nil
 
-	field := metadata.fields["/group/item/leaf"]
+	field := metadata.fields[path.String()]
 	if field.Origin.Operation != childOrigin.Operation {
 		t.Fatalf("final leaf origin operation = %q, want %q", field.Origin.Operation, childOrigin.Operation)
 	}
-	changes := metadata.history["/group/item/leaf"]
+	changes := metadata.History(path)
 	if len(changes) != 2 {
 		t.Fatalf("leaf history has %d entries, want 2: %#v", len(changes), changes)
 	}
 	if changes[0].Origin.Operation != parentOrigin.Operation || changes[1].Origin.Operation != childOrigin.Operation {
 		t.Fatalf("leaf history operations = %q, %q; want %q, %q", changes[0].Origin.Operation, changes[1].Origin.Operation, parentOrigin.Operation, childOrigin.Operation)
 	}
-	for index, change := range changes {
-		if len(change.Previous) != 1 || change.Previous[0].Layer != oldOrigin.Layer {
-			t.Errorf("leaf history[%d] Previous = %#v, want original origin", index, change.Previous)
-		}
-	}
 }
diff --git a/internal/engine/secret.go b/internal/engine/secret.go
index 9f85171..0edb70d 100644
--- a/internal/engine/secret.go
+++ b/internal/engine/secret.go
@@ -11,11 +11,11 @@ type secretDependency struct {
 	dependency Path
 }
 
-func classifySecretPaths(schema *schemaDescriptor, predicate func(Path) bool, metadata Metadata, final *document.Node, applications []historyApplication, projections ...*document.Node) map[string]bool {
-	return classifySecretPathsWithEvidence(schema, predicate, metadata, final, applications, nil, projections...)
+func classifySecretPaths(schema *schemaDescriptor, predicate func(Path) bool, metadata Metadata) map[string]bool {
+	return classifySecretPathsWithEvidence(schema, predicate, metadata, nil)
 }
 
-func classifySecretPathsWithEvidence(schema *schemaDescriptor, predicate func(Path) bool, metadata Metadata, final *document.Node, applications []historyApplication, evidence []*sourceVersionEvidence, projections ...*document.Node) map[string]bool {
+func classifySecretPathsWithEvidence(schema *schemaDescriptor, predicate func(Path) bool, metadata Metadata, evidence []*sourceVersionEvidence) map[string]bool {
 	paths := make(map[string]Path)
 	candidateShapes := make(map[string][]Path)
 	var candidates []Path
@@ -30,19 +30,9 @@ func classifySecretPathsWithEvidence(schema *schemaDescriptor, predicate func(Pa
 		candidateShapes[pointer] = append(candidateShapes[pointer], cloned)
 		candidates = append(candidates, cloned)
 	}
-	for _, application := range applications {
-		walkHistoryApplication(application, func(_ Path, path Path, _ *document.Node) {
-			if len(application.sequences) != 0 {
-				addCandidate(path)
-			} else if parsed, err := ParsePath(path.String()); err == nil {
-				addCandidate(parsed)
-			}
-			addSecretPath(paths, path.String())
-		})
-	}
 	secret := make(map[string]bool)
 	var dependencies, inherited []secretDependency
-	if model := metadata.currentHistoryModel(); model != nil {
+	if model := metadata.historyEvidence(); model != nil {
 		dependencies, inherited = model.sensitivityDependencies()
 		for _, candidate := range model.sensitivityCandidates() {
 			pointer := candidate.path.String()
@@ -71,22 +61,6 @@ func classifySecretPathsWithEvidence(schema *schemaDescriptor, predicate func(Pa
 		}
 	}
 
-	classifyProjection := func(tree *document.Node) {
-		walkDocument(tree, Path{}, func(path Path, node *document.Node) {
-			pointer := path.String()
-			addSecretPath(paths, pointer)
-			if parsed, err := ParsePath(pointer); err == nil {
-				addCandidate(parsed)
-			}
-			if node.Sensitive {
-				secret[pointer] = true
-			}
-		})
-	}
-	for _, tree := range projections {
-		classifyProjection(tree)
-	}
-	classifyProjection(final)
 	classifyPath := func(path Path) {
 		if root, ok := schemaSecretRoot(schema, path); ok {
 			secret[root.String()] = true
diff --git a/internal/engine/secret_classification_test.go b/internal/engine/secret_classification_test.go
index a4177a9..42d5674 100644
--- a/internal/engine/secret_classification_test.go
+++ b/internal/engine/secret_classification_test.go
@@ -42,6 +42,7 @@ func TestSecretClassificationParsesTypedHistoryAfterNumericShapeChanges(t *testi
 			pointer := test.historical.String()
 			builder := newHistoryBuilder()
 			builder.observeDocument(earlier, historyPhaseSources)
+			builder.observeDocument(final, historyPhasePostCLI)
 			metadata := Metadata{historyModel: builder.freeze()}
 			seen := false
 			classified := classifySecretPaths(nil, func(path Path) bool {
@@ -55,7 +56,7 @@ func TestSecretClassificationParsesTypedHistoryAfterNumericShapeChanges(t *testi
 					}
 				}
 				return true
-			}, metadata, final, []historyApplication{{value: earlier}}, earlier)
+			}, metadata)
 			if !seen || !classified[pointer] {
 				t.Fatalf("historical/final numeric path was not classified: %#v", classified)
 			}
@@ -77,7 +78,7 @@ func TestSecretPredicateReceivesDetachedHistoricalPath(t *testing.T) {
 		seen = true
 		candidate.segments[0].key = "changed"
 		return true
-	}, metadata, nil, nil)
+	}, metadata)
 
 	if !seen || !classified[path.String()] || classified["/changed/1"] {
 		t.Fatalf("classification after predicate mutation = %#v, predicate called: %v", classified, seen)
@@ -133,6 +134,9 @@ func TestSourceVersionEvidenceSensitivityUsesOriginalMountedPaths(t *testing.T)
 
 	final := parseCompositionDocument(t, "final", "tenant:\n  groups:\n    blue:\n      - public: shifted-neighbor\n  labels:\n    public: visible\n")
 	var sawOriginalSequencePath, sawAncestorPredicate bool
+	builder := newHistoryBuilder()
+	builder.observeDocument(final, historyPhaseSources)
+	metadata := Metadata{historyModel: builder.freeze()}
 	classified := classifySecretPathsWithEvidence(schema, func(path Path) bool {
 		if path.String() == appendDestination(destination, predicatePath).String() {
 			return true
@@ -151,7 +155,7 @@ func TestSourceVersionEvidenceSensitivityUsesOriginalMountedPaths(t *testing.T)
 			sawOriginalSequencePath = len(path.segments) == 5 && path.segments[3].kind == pathSegmentIndex && path.segments[3].index == 2
 		}
 		return false
-	}, Metadata{}, final, []historyApplication{{path: destination, value: final}}, evidence)
+	}, metadata, evidence)
 
 	for _, path := range []Path{
 		appendDestination(destination, sequencePath),
@@ -197,7 +201,7 @@ func TestSourceVersionEvidenceClassificationKeepsCollidingShapes(t *testing.T) {
 			sawKey = sawKey || reflect.DeepEqual(path, keyPath)
 			sawIndex = sawIndex || reflect.DeepEqual(path, indexPath)
 			return false
-		}, Metadata{}, nil, nil, evidence)
+		}, Metadata{}, evidence)
 		if !classified[keyPath.String()] || !sawKey || !sawIndex {
 			t.Errorf("reverse=%v: classified=%v, key seen=%v, index seen=%v", reverse, classified, sawKey, sawIndex)
 		}