Adopt registry-backed NPC occurrence artifacts

2026-08-05 18:55:58 +00:00
parent 3f4a1f2647
commit 5e2ccffc0f
42 changed files with 676 additions and 528 deletions
--- a/assets/dnd/npc-interactions/prompts/instructions.md
+++ b/assets/dnd/npc-interactions/prompts/instructions.md
@@ -1,7 +1,8 @@
 Extract Dungeons & Dragons NPC interaction occurrences from the supplied
 transcript. Include an occurrence only when the transcript establishes one
 supplied NPC, one interaction kind, and a coherent passage supporting both.
-Use only names from the supplied NPC registry.
+Use the exact `npc_id` and matching `name` pair from the supplied NPC registry;
+never invent an ID or substitute a similar name.

 Do not summarize, infer relationships, sentiment, factions, motives, aliases,
 or persistent state. Do not identify player characters, anonymous groups, or
--- a/assets/dnd/npc-interactions/prompts/prompt.yaml
+++ b/assets/dnd/npc-interactions/prompts/prompt.yaml
@@ -41,5 +41,5 @@ messages:
 output:
  format: json
  validation_mode: json_schema
-  schema_path: dnd_npc_interactions_llm.v1.json
+  schema_path: dnd_npc_occurrences_llm.v1.json
  repair_attempts: 0
--- a/assets/dnd/npc-interactions/schemas/dnd_npc_interactions_llm.v1.json
+++ b/assets/dnd/npc-interactions/schemas/dnd_npc_interactions_llm.v1.json
@@ -1,17 +1,20 @@
 {
  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "notarius.dnd.npc_interactions.llm",
+  "$id": "notarius.dnd.npc_occurrences.llm",
  "type": "object",
  "additionalProperties": false,
-  "required": ["interactions"],
+  "required": ["occurrences"],
  "properties": {
-    "interactions": {
+    "occurrences": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": false,
-        "required": ["name", "kind", "source_refs"],
+        "required": ["npc_id", "name", "kind", "source_refs"],
        "properties": {
+          "npc_id": {
+            "type": "string"
+          },
          "name": {
            "type": "string"
          },
--- a/docs/integrations/dnd-npc-interaction-artifacts.md
+++ b/docs/integrations/dnd-npc-interaction-artifacts.md
@@ -9,22 +9,23 @@ or summarize the session.

 | Property | Value |
 | --- | --- |
-| Artifact kind | `dnd/npc-interaction-list` |
-| Schema ID | `notarius.dnd.npc_interactions` |
-| Schema name | `notarius_dnd_npc_interactions_v1` |
+| Artifact kind | `dnd/npc-occurrence-list` |
+| Schema ID | `notarius.dnd.npc_occurrences` |
+| Schema name | `notarius_dnd_npc_occurrences_v1` |
 | Schema version | `v1` |
 | Media type | `application/json` |

-`v1` is a strict JSON object with required `interactions`; the array may be
-empty. Interaction and source-reference objects reject unknown fields. An
+`v1` is a strict JSON object with required `occurrences`; the array may be
+empty. Occurrence and source-reference objects reject unknown fields. An
 incompatible shape change requires a new schema version.

 ## Wire shape

-Each interaction has these required fields:
+Each occurrence has these required fields:

 | Field | Contract |
 | --- | --- |
+| `npc_id` | Exact durable ID from the required NPC registry. |
 | `name` | Non-empty canonical display name from the required NPC registry. |
 | `kind` | One of the interaction categories below. |
 | `source_refs` | One or more transcript evidence ranges. |
@@ -36,8 +37,9 @@ for an interaction is confined to its accepted chunk.

 ```json
 {
-  "interactions": [
+  "occurrences": [
    {
+      "npc_id": "npc:sha256:example",
      "name": "Mira Thorn",
      "kind": "dialogue",
      "source_refs": [
@@ -65,12 +67,14 @@ for uncertain classification.

 ## Identity, evidence, and order

-The required normalized [NPC registry artifact](dnd-npc-registry-artifacts.md) resolves `name`.
-Registry references are provenance only and never replace an interaction's own
-evidence. Normalization canonicalizes recognized registry names, orders and
+The required normalized [NPC registry artifact](dnd-npc-registry-artifacts.md) resolves
+the exact `{npc_id, name}` pair. Unknown IDs and names that do not match their
+ID are rejected; normalization does not repair names by similarity. Registry
+references are provenance only and never replace an interaction's own evidence.
+Normalization validates the exact pair, orders and
 deduplicates exact source references, then orders interactions by valid source
 chronology, NPC comparison identity, display name, kind, and reference sequence.
-Only entries with the same canonical name, kind, and complete valid evidence
+Only entries with the same NPC ID, canonical name, kind, and complete valid evidence
 sequence are collapsed; distinct categories or evidence remain separate.

 See the [combat-turn artifact](dnd-combat-turn-artifacts.md) for combat-action
--- a/internal/cli/dnd_enemy_events_contract_test.go
+++ b/internal/cli/dnd_enemy_events_contract_test.go
@@ -259,9 +259,20 @@ func (client *enemyEventLLMClient) CompleteStructured(ctx context.Context, reque
 		content = []byte(`{"combat_turns":[{"actor":"Kesh","turn_kind":"turn","source_refs":[{"start_unit_id":8,"end_unit_id":8}]}]}`)
 	case npcinteractions.PromptID:
 		if combatScene {
-			content = []byte(`{"interactions":[{"name":"Kesh","kind":"combat_opponent","source_refs":[{"start_unit_id":7,"end_unit_id":7}]}]}`)
+			var registry struct {
+				NPCs []struct {
+					ID string `json:"id"`
+				} `json:"npcs"`
+			}
+			if err := json.Unmarshal(request.Inputs["npc_registry"].Content, &registry); err != nil {
+				return contracts.StructuredCompletionResponse{}, fmt.Errorf("decode generated NPC registry: %w", err)
+			}
+			if len(registry.NPCs) == 0 {
+				return contracts.StructuredCompletionResponse{}, fmt.Errorf("generated NPC registry has no NPCs")
+			}
+			content = []byte(fmt.Sprintf(`{"occurrences":[{"npc_id":%q,"name":"Kesh","kind":"combat_opponent","source_refs":[{"start_unit_id":7,"end_unit_id":7}]}]}`, registry.NPCs[0].ID))
 		} else {
-			content = []byte(`{"interactions":[]}`)
+			content = []byte(`{"occurrences":[]}`)
 		}
 	case locationoccurrences.PromptID:
 		var registry struct {
--- a/internal/cli/dnd_interactions_contract_test.go
+++ b/internal/cli/dnd_interactions_contract_test.go
@@ -25,7 +25,7 @@ func TestProductionNPCInteractionPipelineResolvesAndPrepares(t *testing.T) {
 		t.Fatalf("resolved pipeline = %#v", resolved)
 	}
 	lane := resolved.Steps[1].ArtifactLanes[0]
-	if lane.ArtifactKind != dnd.NPCInteractionListKind || lane.Extract.Module != interactionextract.Key || lane.Normalize.Module != interactionnormalize.Key {
+	if lane.ArtifactKind != dnd.NPCOccurrenceListKind || lane.Extract.Module != interactionextract.Key || lane.Normalize.Module != interactionnormalize.Key {
 		t.Fatalf("interaction lane = %#v", lane)
 	}
 	for _, bindings := range [][]pipeline.ReferenceBinding{lane.ExtractReferences.Bindings, lane.NormalizeReferences.Bindings} {
@@ -38,7 +38,7 @@ func TestProductionNPCInteractionPipelineResolvesAndPrepares(t *testing.T) {
 	}

 	catalog := catalogFromRegistries(components.registries)
-	codecSpec, ok := catalog.ArtifactCodecs.Spec(dnd.NPCInteractionListKind)
+	codecSpec, ok := catalog.ArtifactCodecs.Spec(dnd.NPCOccurrenceListKind)
 	if !ok || codecSpec.Schema.ID != interactioncodec.SchemaID || codecSpec.Schema.Version != interactioncodec.SchemaVersion {
 		t.Fatalf("NPC interaction codec spec = %#v", codecSpec)
 	}
--- a/internal/modules/dnd/codec/npcinteractions/assets/schemas/dnd_npc_interactions.v1.json
+++ b/internal/modules/dnd/codec/npcinteractions/assets/schemas/dnd_npc_interactions.v1.json
@@ -1,17 +1,21 @@
 {
  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "notarius.dnd.npc_interactions",
+  "$id": "notarius.dnd.npc_occurrences",
  "type": "object",
  "additionalProperties": false,
-  "required": ["interactions"],
+  "required": ["occurrences"],
  "properties": {
-    "interactions": {
+    "occurrences": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": false,
-        "required": ["name", "kind", "source_refs"],
+        "required": ["npc_id", "name", "kind", "source_refs"],
        "properties": {
+          "npc_id": {
+            "type": "string",
+            "minLength": 1
+          },
          "name": {
            "type": "string",
            "minLength": 1
--- a/internal/modules/dnd/codec/npcinteractions/codec.go
+++ b/internal/modules/dnd/codec/npcinteractions/codec.go
@@ -1,4 +1,4 @@
-// Package npcinteractions encodes durable D&D NPC interaction artifacts.
+// Package npcinteractions encodes durable D&D NPC occurrence artifacts.
 package npcinteractions

 import (
@@ -12,25 +12,25 @@ import (
 )

 const (
-	SchemaID      = "notarius.dnd.npc_interactions"
-	SchemaName    = "notarius_dnd_npc_interactions_v1"
+	SchemaID      = "notarius.dnd.npc_occurrences"
+	SchemaName    = "notarius_dnd_npc_occurrences_v1"
 	SchemaVersion = "v1"
 	MediaType     = "application/json"
 )

-//go:embed assets/schemas/dnd_npc_interactions.v1.json
+//go:embed assets/schemas/dnd_npc_occurrences.v1.json
 var schemaAssets embed.FS

-var _ contracts.ArtifactCodec[dnd.NPCInteractionList] = (*Codec)(nil)
+var _ contracts.ArtifactCodec[dnd.NPCOccurrenceList] = (*Codec)(nil)

 type Codec struct{}

 func New() *Codec { return &Codec{} }

-func (c *Codec) Kind() contracts.ArtifactKind { return dnd.NPCInteractionListKind }
+func (c *Codec) Kind() contracts.ArtifactKind { return dnd.NPCOccurrenceListKind }

 func (c *Codec) Schema() contracts.ArtifactSchema {
-	raw, err := schemaAssets.ReadFile("assets/schemas/dnd_npc_interactions.v1.json")
+	raw, err := schemaAssets.ReadFile("assets/schemas/dnd_npc_occurrences.v1.json")
 	if err != nil {
 		return contracts.ArtifactSchema{}
 	}
@@ -44,56 +44,59 @@ func (c *Codec) Schema() contracts.ArtifactSchema {

 func (c *Codec) MediaType() string { return MediaType }

-func (c *Codec) Metadata(value dnd.NPCInteractionList) map[string]any {
-	return map[string]any{"interaction_count": len(value.Interactions)}
+func (c *Codec) Metadata(value dnd.NPCOccurrenceList) map[string]any {
+	return map[string]any{"occurrence_count": len(value.Occurrences)}
 }

-func (c *Codec) Encode(value dnd.NPCInteractionList) ([]byte, error) {
+func (c *Codec) Encode(value dnd.NPCOccurrenceList) ([]byte, error) {
 	if err := validate(value); err != nil {
-		return nil, fmt.Errorf("encode dnd npc interaction list: %w", err)
+		return nil, fmt.Errorf("encode dnd npc occurrence list: %w", err)
 	}
 	return c.EncodeCandidate(value)
 }

 // EncodeCandidate provides the durable representation before semantic
 // validators have approved a value.
-func (c *Codec) EncodeCandidate(value dnd.NPCInteractionList) ([]byte, error) {
-	return candidatejson.EncodeCandidate("dnd npc interaction list", value)
+func (c *Codec) EncodeCandidate(value dnd.NPCOccurrenceList) ([]byte, error) {
+	return candidatejson.EncodeCandidate("dnd npc occurrence list", value)
 }

-func (c *Codec) Decode(content []byte) (dnd.NPCInteractionList, error) {
+func (c *Codec) Decode(content []byte) (dnd.NPCOccurrenceList, error) {
 	value, err := c.DecodeCandidate(content)
 	if err != nil {
-		return dnd.NPCInteractionList{}, err
+		return dnd.NPCOccurrenceList{}, err
 	}
 	if err := validate(value); err != nil {
-		return dnd.NPCInteractionList{}, fmt.Errorf("decode dnd npc interaction list: %w", err)
+		return dnd.NPCOccurrenceList{}, fmt.Errorf("decode dnd npc occurrence list: %w", err)
 	}
 	return value, nil
 }

 // DecodeCandidate reads one strict durable JSON value before semantic
 // validators have approved it.
-func (c *Codec) DecodeCandidate(content []byte) (dnd.NPCInteractionList, error) {
-	return candidatejson.DecodeCandidate[dnd.NPCInteractionList]("dnd npc interaction list", content)
+func (c *Codec) DecodeCandidate(content []byte) (dnd.NPCOccurrenceList, error) {
+	return candidatejson.DecodeCandidate[dnd.NPCOccurrenceList]("dnd npc occurrence list", content)
 }

-func validate(value dnd.NPCInteractionList) error {
-	if value.Interactions == nil {
-		return fmt.Errorf("interactions must be present")
+func validate(value dnd.NPCOccurrenceList) error {
+	if value.Occurrences == nil {
+		return fmt.Errorf("occurrences must be present")
 	}
-	for index, interaction := range value.Interactions {
-		prefix := fmt.Sprintf("interactions[%d]", index)
-		if strings.TrimSpace(interaction.Name) == "" {
+	for index, occurrence := range value.Occurrences {
+		prefix := fmt.Sprintf("occurrences[%d]", index)
+		if strings.TrimSpace(occurrence.NPCID) == "" {
+			return fmt.Errorf("%s.npc_id must not be empty", prefix)
+		}
+		if strings.TrimSpace(occurrence.Name) == "" {
 			return fmt.Errorf("%s.name must not be empty", prefix)
 		}
-		if !validInteractionKind(interaction.Kind) {
+		if !validOccurrenceKind(occurrence.Kind) {
 			return fmt.Errorf("%s.kind must be supported", prefix)
 		}
-		if len(interaction.SourceRefs) == 0 {
+		if len(occurrence.SourceRefs) == 0 {
 			return fmt.Errorf("%s.source_refs must contain at least one reference", prefix)
 		}
-		for refIndex, ref := range interaction.SourceRefs {
+		for refIndex, ref := range occurrence.SourceRefs {
 			refPrefix := fmt.Sprintf("%s.source_refs[%d]", prefix, refIndex)
 			if strings.TrimSpace(ref.SourceID) == "" {
 				return fmt.Errorf("%s.source_id must not be empty", refPrefix)
@@ -109,14 +112,14 @@ func validate(value dnd.NPCInteractionList) error {
 	return nil
 }

-func validInteractionKind(value dnd.NPCInteractionKind) bool {
+func validOccurrenceKind(value dnd.NPCOccurrenceKind) bool {
 	switch value {
-	case dnd.NPCInteractionKindMentioned,
-		dnd.NPCInteractionKindNoncombatPresence,
-		dnd.NPCInteractionKindDialogue,
-		dnd.NPCInteractionKindCombatAlly,
-		dnd.NPCInteractionKindCombatOpponent,
-		dnd.NPCInteractionKindOther:
+	case dnd.NPCOccurrenceKindMentioned,
+		dnd.NPCOccurrenceKindNoncombatPresence,
+		dnd.NPCOccurrenceKindDialogue,
+		dnd.NPCOccurrenceKindCombatAlly,
+		dnd.NPCOccurrenceKindCombatOpponent,
+		dnd.NPCOccurrenceKindOther:
 		return true
 	default:
 		return false
--- a/internal/modules/dnd/codec/npcinteractions/codec_test.go
+++ b/internal/modules/dnd/codec/npcinteractions/codec_test.go
@@ -15,21 +15,21 @@ import (
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
 )

-func validList() dnd.NPCInteractionList {
-	return dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{
+func validList() dnd.NPCOccurrenceList {
+	return dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{
 		{
-			Name: "Mira Thorn", Kind: dnd.NPCInteractionKindDialogue,
+			NPCID: "npc:test-mira", Name: "Mira Thorn", Kind: dnd.NPCOccurrenceKindDialogue,
 			SourceRefs: []source.SourceRef{{SourceID: "session-alpha", StartUnitID: 1, EndUnitID: 2}},
 		},
 		{
-			Name: "Hooded Guard", Kind: dnd.NPCInteractionKindCombatOpponent,
+			NPCID: "npc:test-guard", Name: "Hooded Guard", Kind: dnd.NPCOccurrenceKindCombatOpponent,
 			SourceRefs: []source.SourceRef{{SourceID: "session-alpha", StartUnitID: 3, EndUnitID: 3}},
 		},
 	}}
 }

 func TestCodecMatchesMaintainedDurableFixture(t *testing.T) {
-	raw, err := os.ReadFile("testdata/dnd_npc_interactions.v1.json")
+	raw, err := os.ReadFile("testdata/dnd_npc_occurrences.v1.json")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -57,7 +57,7 @@ func TestCodecMatchesMaintainedDurableFixture(t *testing.T) {
 func TestCodecOwnsDurableSchemaAndRegistersExactType(t *testing.T) {
 	codec := New()
 	schema := codec.Schema()
-	if codec.Kind() != dnd.NPCInteractionListKind || codec.MediaType() != MediaType {
+	if codec.Kind() != dnd.NPCOccurrenceListKind || codec.MediaType() != MediaType {
 		t.Fatalf("codec identity = %q/%q", codec.Kind(), codec.MediaType())
 	}
 	if schema.ID != SchemaID || schema.Name != SchemaName || schema.Version != SchemaVersion || !json.Valid(schema.JSONSchema) {
@@ -67,11 +67,11 @@ func TestCodecOwnsDurableSchemaAndRegistersExactType(t *testing.T) {
 	if err := pipeline.RegisterArtifactCodec(registry, codec); err != nil {
 		t.Fatal(err)
 	}
-	spec, ok := registry.Spec(dnd.NPCInteractionListKind)
+	spec, ok := registry.Spec(dnd.NPCOccurrenceListKind)
 	if !ok || spec.SchemaDigest != contracts.DigestArtifactSchema(schema) {
 		t.Fatalf("registered spec = %#v, %t", spec, ok)
 	}
-	if _, err := registry.Encode(dnd.NPCInteractionListKind, dnd.NPCRegistry{}); err == nil {
+	if _, err := registry.Encode(dnd.NPCOccurrenceListKind, dnd.NPCRegistry{}); err == nil {
 		t.Fatal("Encode() error = nil, want exact type rejection")
 	} else {
 		var typeErr *pipeline.ArtifactCodecTypeError
@@ -83,17 +83,17 @@ func TestCodecOwnsDurableSchemaAndRegistersExactType(t *testing.T) {

 func TestCodecSupportsEmptyListAndPreservesCollectionPresenceInCandidates(t *testing.T) {
 	codec := New()
-	empty := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{}}
+	empty := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{}}
 	content, err := codec.Encode(empty)
-	if err != nil || string(content) != `{"interactions":[]}` {
+	if err != nil || string(content) != `{"occurrences":[]}` {
 		t.Fatalf("Encode() = %s, %v", content, err)
 	}
-	for _, candidate := range []dnd.NPCInteractionList{
+	for _, candidate := range []dnd.NPCOccurrenceList{
 		{},
 		empty,
-		{Interactions: []dnd.NPCInteraction{{Name: " ", Kind: "unsupported", SourceRefs: nil}}},
-		{Interactions: []dnd.NPCInteraction{{Name: " ", Kind: "unsupported", SourceRefs: []source.SourceRef{}}}},
-		{Interactions: []dnd.NPCInteraction{{Name: " ", Kind: "unsupported", SourceRefs: []source.SourceRef{{StartUnitID: 0, EndUnitID: -1}}}}},
+		{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: " ", Kind: "unsupported", SourceRefs: nil}}},
+		{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: " ", Kind: "unsupported", SourceRefs: []source.SourceRef{}}}},
+		{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: " ", Kind: "unsupported", SourceRefs: []source.SourceRef{{StartUnitID: 0, EndUnitID: -1}}}}},
 	} {
 		content, err := codec.EncodeCandidate(candidate)
 		if err != nil || !json.Valid(content) {
@@ -107,13 +107,13 @@ func TestCodecSupportsEmptyListAndPreservesCollectionPresenceInCandidates(t *tes
 }

 func TestCodecStrictlyRejectsMalformedUnknownAndTrailingJSON(t *testing.T) {
-	validJSON := `{"interactions":[{"name":"Mira Thorn","kind":"dialogue","source_refs":[{"source_id":"session","start_unit_id":1,"end_unit_id":1}]}]}`
+	validJSON := `{"occurrences":[{"npc_id":"npc:test-mira","name":"Mira Thorn","kind":"dialogue","source_refs":[{"source_id":"session","start_unit_id":1,"end_unit_id":1}]}]}`
 	for _, test := range []struct{ name, raw, want string }{
-		{"malformed", `{`, "decode dnd npc interaction list"},
-		{"unknown top-level", `{"interactions":[],"unexpected":true}`, "unknown field"},
+		{"malformed", `{`, "decode dnd npc occurrence list"},
+		{"unknown top-level", `{"occurrences":[],"unexpected":true}`, "unknown field"},
 		{"unknown interaction field", strings.Replace(validJSON, `"kind":"dialogue"`, `"kind":"dialogue","unexpected":true`, 1), "unknown field"},
 		{"unknown source reference field", strings.Replace(validJSON, `"end_unit_id":1`, `"end_unit_id":1,"unexpected":true`, 1), "unknown field"},
-		{"trailing", `{"interactions":[]} {}`, "multiple JSON values"},
+		{"trailing", `{"occurrences":[]} {}`, "multiple JSON values"},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			if _, err := New().Decode([]byte(test.raw)); err == nil || !strings.Contains(err.Error(), test.want) {
@@ -126,16 +126,17 @@ func TestCodecStrictlyRejectsMalformedUnknownAndTrailingJSON(t *testing.T) {
 func TestCodecRejectsRequiredShapeEnumAndReferenceBoundaries(t *testing.T) {
 	tests := []struct {
 		name  string
-		value dnd.NPCInteractionList
+		value dnd.NPCOccurrenceList
 		want  string
 	}{
-		{"nil interactions", dnd.NPCInteractionList{}, "interactions must be present"},
-		{"blank name", mutate(validList(), func(v *dnd.NPCInteractionList) { v.Interactions[0].Name = " " }), "name must not be empty"},
-		{"unsupported kind", mutate(validList(), func(v *dnd.NPCInteractionList) { v.Interactions[0].Kind = "unsupported" }), "kind must be supported"},
-		{"nil source refs", mutate(validList(), func(v *dnd.NPCInteractionList) { v.Interactions[0].SourceRefs = nil }), "source_refs must contain"},
-		{"empty source ID", mutate(validList(), func(v *dnd.NPCInteractionList) { v.Interactions[0].SourceRefs[0].SourceID = " " }), "source_id must not be empty"},
-		{"non-positive start", mutate(validList(), func(v *dnd.NPCInteractionList) { v.Interactions[0].SourceRefs[0].StartUnitID = 0 }), "start_unit_id must be positive"},
-		{"non-positive end", mutate(validList(), func(v *dnd.NPCInteractionList) { v.Interactions[0].SourceRefs[0].EndUnitID = 0 }), "end_unit_id must be positive"},
+		{"nil occurrences", dnd.NPCOccurrenceList{}, "occurrences must be present"},
+		{"blank NPC ID", mutate(validList(), func(v *dnd.NPCOccurrenceList) { v.Occurrences[0].NPCID = " " }), "npc_id must not be empty"},
+		{"blank name", mutate(validList(), func(v *dnd.NPCOccurrenceList) { v.Occurrences[0].Name = " " }), "name must not be empty"},
+		{"unsupported kind", mutate(validList(), func(v *dnd.NPCOccurrenceList) { v.Occurrences[0].Kind = "unsupported" }), "kind must be supported"},
+		{"nil source refs", mutate(validList(), func(v *dnd.NPCOccurrenceList) { v.Occurrences[0].SourceRefs = nil }), "source_refs must contain"},
+		{"empty source ID", mutate(validList(), func(v *dnd.NPCOccurrenceList) { v.Occurrences[0].SourceRefs[0].SourceID = " " }), "source_id must not be empty"},
+		{"non-positive start", mutate(validList(), func(v *dnd.NPCOccurrenceList) { v.Occurrences[0].SourceRefs[0].StartUnitID = 0 }), "start_unit_id must be positive"},
+		{"non-positive end", mutate(validList(), func(v *dnd.NPCOccurrenceList) { v.Occurrences[0].SourceRefs[0].EndUnitID = 0 }), "end_unit_id must be positive"},
 	}
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
@@ -147,16 +148,16 @@ func TestCodecRejectsRequiredShapeEnumAndReferenceBoundaries(t *testing.T) {
 }

 func TestCodecAcceptsEveryInteractionKind(t *testing.T) {
-	for _, kind := range []dnd.NPCInteractionKind{
-		dnd.NPCInteractionKindMentioned,
-		dnd.NPCInteractionKindNoncombatPresence,
-		dnd.NPCInteractionKindDialogue,
-		dnd.NPCInteractionKindCombatAlly,
-		dnd.NPCInteractionKindCombatOpponent,
-		dnd.NPCInteractionKindOther,
+	for _, kind := range []dnd.NPCOccurrenceKind{
+		dnd.NPCOccurrenceKindMentioned,
+		dnd.NPCOccurrenceKindNoncombatPresence,
+		dnd.NPCOccurrenceKindDialogue,
+		dnd.NPCOccurrenceKindCombatAlly,
+		dnd.NPCOccurrenceKindCombatOpponent,
+		dnd.NPCOccurrenceKindOther,
 	} {
 		value := validList()
-		value.Interactions[0].Kind = kind
+		value.Occurrences[0].Kind = kind
 		if _, err := New().Encode(value); err != nil {
 			t.Fatalf("Encode(%q) error = %v", kind, err)
 		}
@@ -172,12 +173,12 @@ func TestCodecSchemaAndMetadataAreDefensive(t *testing.T) {
 	}
 	metadata := codec.Metadata(validList())
 	metadata["other"] = true
-	if next := codec.Metadata(validList()); len(next) != 1 || next["interaction_count"] != 2 {
+	if next := codec.Metadata(validList()); len(next) != 1 || next["occurrence_count"] != 2 {
 		t.Fatalf("Metadata() = %#v", next)
 	}
 }

-func mutate(value dnd.NPCInteractionList, change func(*dnd.NPCInteractionList)) dnd.NPCInteractionList {
+func mutate(value dnd.NPCOccurrenceList, change func(*dnd.NPCOccurrenceList)) dnd.NPCOccurrenceList {
 	change(&value)
 	return value
 }
--- a/internal/modules/dnd/codec/npcinteractions/testdata/dnd_npc_interactions.v1.json
+++ b/internal/modules/dnd/codec/npcinteractions/testdata/dnd_npc_interactions.v1.json
@@ -1,6 +1,7 @@
 {
-  "interactions": [
+  "occurrences": [
    {
+      "npc_id": "npc:test-mira",
      "name": "Mira Thorn",
      "kind": "dialogue",
      "source_refs": [
@@ -8,6 +9,7 @@
      ]
    },
    {
+      "npc_id": "npc:test-guard",
      "name": "Hooded Guard",
      "kind": "combat_opponent",
      "source_refs": [
--- a/internal/modules/dnd/extract/enemyevents/grounding.go
+++ b/internal/modules/dnd/extract/enemyevents/grounding.go
@@ -71,7 +71,7 @@ func referenceSlots() []contracts.ReferenceSlot {
 			Description:           "Required NPC-interaction artifact used only as source-free enemy-event grounding.",
 			Required:              true,
 			AcceptedMediaTypes:    []string{interactioncodec.MediaType},
-			AcceptedArtifactKinds: []contracts.ArtifactKind{dnd.NPCInteractionListKind},
+			AcceptedArtifactKinds: []contracts.ArtifactKind{dnd.NPCOccurrenceListKind},
 			MaxBytes:              ReferenceMaxBytes,
 		},
 	)
@@ -223,7 +223,7 @@ func prepareNPCInteractionInput(references contracts.ReferenceSet) (*contracts.L
 	}
 	content, err := json.Marshal(struct {
 		Interactions []npcInteractionProjection `json:"npc_interactions"`
-	}{Interactions: projectNPCInteractions(value.Interactions)})
+	}{Interactions: projectNPCInteractions(value.Occurrences)})
 	if err != nil {
 		return nil, fmt.Errorf("encode NPC-interaction grounding: %w", err)
 	}
@@ -272,15 +272,15 @@ func projectCombatTurns(turns []dnd.CombatTurn) []combatTurnProjection {
 }

 type npcInteractionProjection struct {
-	Name string                 `json:"name"`
-	Kind dnd.NPCInteractionKind `json:"kind"`
+	Name string                `json:"name"`
+	Kind dnd.NPCOccurrenceKind `json:"kind"`
 }

-func projectNPCInteractions(interactions []dnd.NPCInteraction) []npcInteractionProjection {
-	projection := make([]npcInteractionProjection, 0, len(interactions))
-	for _, interaction := range interactions {
-		if interaction.Kind == dnd.NPCInteractionKindCombatOpponent {
-			projection = append(projection, npcInteractionProjection{Name: interaction.Name, Kind: interaction.Kind})
+func projectNPCInteractions(occurrences []dnd.NPCOccurrence) []npcInteractionProjection {
+	projection := make([]npcInteractionProjection, 0, len(occurrences))
+	for _, occurrence := range occurrences {
+		if occurrence.Kind == dnd.NPCOccurrenceKindCombatOpponent {
+			projection = append(projection, npcInteractionProjection{Name: occurrence.Name, Kind: occurrence.Kind})
 		}
 	}
 	return projection
--- a/internal/modules/dnd/extract/enemyevents/grounding_test.go
+++ b/internal/modules/dnd/extract/enemyevents/grounding_test.go
@@ -36,7 +36,7 @@ func TestReferenceSlotsDescribeRequiredTypedArtifacts(t *testing.T) {
 		{NPCRegistryReferenceSlot, dnd.NPCRegistryKind},
 		{SceneDescriptionReferenceSlot, dnd.SceneDescriptionListKind},
 		{CombatTurnReferenceSlot, dnd.CombatTurnListKind},
-		{NPCInteractionReferenceSlot, dnd.NPCInteractionListKind},
+		{NPCInteractionReferenceSlot, dnd.NPCOccurrenceListKind},
 	} {
 		slot, ok := byName[want.name]
 		if !ok || !slot.Required || slot.MaxBytes != ReferenceMaxBytes || len(slot.AcceptedMediaTypes) != 1 || slot.AcceptedMediaTypes[0] != "application/json" || len(slot.AcceptedArtifactKinds) != 1 || slot.AcceptedArtifactKinds[0] != want.kind {
@@ -220,9 +220,9 @@ func groundingReferences(t *testing.T, enemy string, sceneKind dnd.SceneKind) co
 	if err != nil {
 		t.Fatal(err)
 	}
-	interactionContent, err := interactioncodec.New().Encode(dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{
-		{Name: enemy, Kind: dnd.NPCInteractionKindCombatOpponent, SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 1, EndUnitID: 1}}},
-		{Name: "Aria", Kind: dnd.NPCInteractionKindCombatAlly, SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 2, EndUnitID: 2}}},
+	interactionContent, err := interactioncodec.New().Encode(dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{
+		{NPCID: identity.DeriveID(enemy), Name: enemy, Kind: dnd.NPCOccurrenceKindCombatOpponent, SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 1, EndUnitID: 1}}},
+		{NPCID: identity.DeriveID("Aria"), Name: "Aria", Kind: dnd.NPCOccurrenceKindCombatAlly, SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 2, EndUnitID: 2}}},
 	}})
 	if err != nil {
 		t.Fatal(err)
--- a/internal/modules/dnd/extract/npcinteractions/canonicalize.go
+++ b/internal/modules/dnd/extract/npcinteractions/canonicalize.go
@@ -8,8 +8,8 @@ import (
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared"
 )

-type orderedInteractionResponse struct {
-	value       interactionResponse
+type orderedOccurrenceResponse struct {
+	value       occurrenceResponse
 	earliest    int
 	hasEvidence bool
 }
@@ -18,11 +18,11 @@ func canonicalizeResponse(response *extractionResponse, order shared.SourceRefOr
 	if response == nil {
 		return
 	}
-	ordered := make([]orderedInteractionResponse, len(response.Interactions))
-	for index := range response.Interactions {
-		earliest, hasEvidence := canonicalizeInteraction(&response.Interactions[index], order, sourceID)
-		ordered[index] = orderedInteractionResponse{
-			value:       response.Interactions[index],
+	ordered := make([]orderedOccurrenceResponse, len(response.Occurrences))
+	for index := range response.Occurrences {
+		earliest, hasEvidence := canonicalizeOccurrence(&response.Occurrences[index], order, sourceID)
+		ordered[index] = orderedOccurrenceResponse{
+			value:       response.Occurrences[index],
 			earliest:    earliest,
 			hasEvidence: hasEvidence,
 		}
@@ -37,32 +37,33 @@ func canonicalizeResponse(response *extractionResponse, order shared.SourceRefOr
 		return ordered[i].earliest < ordered[j].earliest
 	})
 	for index := range ordered {
-		response.Interactions[index] = ordered[index].value
+		response.Occurrences[index] = ordered[index].value
 	}
 }

-func canonicalizeInteraction(interaction *interactionResponse, order shared.SourceRefOrder, sourceID string) (int, bool) {
-	if interaction == nil {
+func canonicalizeOccurrence(occurrence *occurrenceResponse, order shared.SourceRefOrder, sourceID string) (int, bool) {
+	if occurrence == nil {
 		return 0, false
 	}
-	refs := order.Canonicalize(canonicalSourceRefs(interaction.SourceRefs, sourceID))
-	interaction.SourceRefs = interactionResponseRefs(refs)
+	refs := order.Canonicalize(canonicalSourceRefs(occurrence.SourceRefs, sourceID))
+	occurrence.SourceRefs = occurrenceResponseRefs(refs)
 	return order.EarliestValid(refs)
 }

-func canonicalInteractionList(response extractionResponse, sourceID string) dnd.NPCInteractionList {
-	interactions := make([]dnd.NPCInteraction, len(response.Interactions))
-	for index, interaction := range response.Interactions {
-		interactions[index] = dnd.NPCInteraction{
-			Name:       interaction.Name,
-			Kind:       dnd.NPCInteractionKind(interaction.Kind),
-			SourceRefs: canonicalSourceRefs(interaction.SourceRefs, sourceID),
+func canonicalOccurrenceList(response extractionResponse, sourceID string) dnd.NPCOccurrenceList {
+	occurrences := make([]dnd.NPCOccurrence, len(response.Occurrences))
+	for index, occurrence := range response.Occurrences {
+		occurrences[index] = dnd.NPCOccurrence{
+			NPCID:      occurrence.NPCID,
+			Name:       occurrence.Name,
+			Kind:       dnd.NPCOccurrenceKind(occurrence.Kind),
+			SourceRefs: canonicalSourceRefs(occurrence.SourceRefs, sourceID),
 		}
 	}
-	if response.Interactions == nil {
-		interactions = nil
+	if response.Occurrences == nil {
+		occurrences = nil
 	}
-	return dnd.NPCInteractionList{Interactions: interactions}
+	return dnd.NPCOccurrenceList{Occurrences: occurrences}
 }

 func canonicalSourceRefs(refs []interactionSourceRefResponse, sourceID string) []source.SourceRef {
@@ -76,7 +77,7 @@ func canonicalSourceRefs(refs []interactionSourceRefResponse, sourceID string) [
 	return out
 }

-func interactionResponseRefs(refs []source.SourceRef) []interactionSourceRefResponse {
+func occurrenceResponseRefs(refs []source.SourceRef) []interactionSourceRefResponse {
 	if refs == nil {
 		return nil
 	}
--- a/internal/modules/dnd/extract/npcinteractions/extractor.go
+++ b/internal/modules/dnd/extract/npcinteractions/extractor.go
@@ -52,7 +52,7 @@ func referenceSlots() []contracts.ReferenceSlot {
 	return slots
 }

-var _ contracts.Extractor[dnd.NPCInteractionList] = (*Extractor)(nil)
+var _ contracts.Extractor[dnd.NPCOccurrenceList] = (*Extractor)(nil)
 var _ contracts.ManifestMetadataProvider = (*Extractor)(nil)
 var _ pipeline.CheckpointFingerprintProvider = (*Extractor)(nil)

@@ -132,33 +132,33 @@ func (e *Extractor) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
 		{Name: "prompt", Value: e.promptSHA},
 		{Name: "response_schema", Value: e.responseSchemaSHA},
 		{Name: "mapping_policy", Value: mappingPolicy},
-		{Name: "npc_registry", Value: seeded.ProjectionDigest()},
+		{Name: "npc_registry", Value: seeded.IdentityPromptInput().Digest},
 	}
 }

-func (e *Extractor) Extract(ctx context.Context, req contracts.TypedExtractionRequest) (contracts.TypedExtractionResult[dnd.NPCInteractionList], error) {
+func (e *Extractor) Extract(ctx context.Context, req contracts.TypedExtractionRequest) (contracts.TypedExtractionResult[dnd.NPCOccurrenceList], error) {
 	if e == nil {
-		return contracts.TypedExtractionResult[dnd.NPCInteractionList]{}, extractorErrorf("extractor must not be nil")
+		return contracts.TypedExtractionResult[dnd.NPCOccurrenceList]{}, extractorErrorf("extractor must not be nil")
 	}
 	if e.llm == nil {
-		return contracts.TypedExtractionResult[dnd.NPCInteractionList]{}, extractorErrorf("LLM client must not be nil")
+		return contracts.TypedExtractionResult[dnd.NPCOccurrenceList]{}, extractorErrorf("LLM client must not be nil")
 	}
 	sourceInput, err := shared.PrepareChunkExtraction(ctx, req)
 	if err != nil {
-		return contracts.TypedExtractionResult[dnd.NPCInteractionList]{}, extractorErrorf("%w", err)
+		return contracts.TypedExtractionResult[dnd.NPCOccurrenceList]{}, extractorErrorf("%w", err)
 	}
 	order := shared.NewSourceRefOrder(req.Source)
 	npcRegistry, err := e.npcResolver.Resolve(req.References)
 	if err != nil {
-		return contracts.TypedExtractionResult[dnd.NPCInteractionList]{}, extractorErrorf("resolve NPC registry: %w", err)
+		return contracts.TypedExtractionResult[dnd.NPCOccurrenceList]{}, extractorErrorf("resolve NPC registry: %w", err)
 	}
 	if !npcRegistry.Bound() {
-		return contracts.TypedExtractionResult[dnd.NPCInteractionList]{}, extractorErrorf("NPC registry reference is required")
+		return contracts.TypedExtractionResult[dnd.NPCOccurrenceList]{}, extractorErrorf("NPC registry reference is required")
 	}

 	var response extractionResponse
 	inputs := shared.PromptInputs(sourceInput, req.References)
-	inputs[NPCRegistryReferenceSlot] = npcRegistry.PromptInput()
+	inputs[NPCRegistryReferenceSlot] = npcRegistry.IdentityPromptInput()
 	if _, err := e.llm.CompleteStructured(ctx, contracts.StructuredCompletionRequest{
 		StageName:     Key,
 		PromptID:      PromptID,
@@ -167,10 +167,27 @@ func (e *Extractor) Extract(ctx context.Context, req contracts.TypedExtractionRe
 		SessionID:     req.SessionID,
 		Inputs:        inputs,
 	}, &response); err != nil {
-		return contracts.TypedExtractionResult[dnd.NPCInteractionList]{}, extractorErrorf("complete structured output: %w", err)
+		return contracts.TypedExtractionResult[dnd.NPCOccurrenceList]{}, extractorErrorf("complete structured output: %w", err)
 	}
 	canonicalizeResponse(&response, order, req.Source.ID)
-	return contracts.TypedExtractionResult[dnd.NPCInteractionList]{Value: canonicalInteractionList(response, req.Source.ID)}, nil
+	value := canonicalOccurrenceList(response, req.Source.ID)
+	if err := validateRegistryPairs(value, npcRegistry); err != nil {
+		return contracts.TypedExtractionResult[dnd.NPCOccurrenceList]{}, extractorErrorf("validate NPC registry pairs: %w", err)
+	}
+	return contracts.TypedExtractionResult[dnd.NPCOccurrenceList]{Value: value}, nil
+}
+
+func validateRegistryPairs(value dnd.NPCOccurrenceList, registry *npcregistry.Registry) error {
+	for index, occurrence := range value.Occurrences {
+		canonical, ok := registry.LookupID(occurrence.NPCID)
+		if !ok {
+			return fmt.Errorf("occurrences[%d].npc_id is not in the NPC registry", index)
+		}
+		if occurrence.Name != canonical.Name {
+			return fmt.Errorf("occurrences[%d].name does not match npc_id", index)
+		}
+	}
+	return nil
 }

 func ModuleSpec() pipeline.ModuleSpec {
@@ -180,13 +197,13 @@ func ModuleSpec() pipeline.ModuleSpec {
 		ExecutionClass: contracts.ExecutionClassLLMBacked,
 		Requires:       append([]string(nil), requiredCapabilities...),
 		Provides:       append([]string(nil), providedCapabilities...),
-		ArtifactKind:   dnd.NPCInteractionListKind,
+		ArtifactKind:   dnd.NPCOccurrenceListKind,
 		ReferenceSlots: referenceSlots(),
 	}
 }

 func Register(registry *pipeline.ExtractorRegistry) error {
-	return pipeline.RegisterExtractorBuilder(registry, ModuleSpec(), validateOptions, func(request pipeline.BuildRequest) (contracts.Extractor[dnd.NPCInteractionList], error) {
+	return pipeline.RegisterExtractorBuilder(registry, ModuleSpec(), validateOptions, func(request pipeline.BuildRequest) (contracts.Extractor[dnd.NPCOccurrenceList], error) {
 		options, err := DecodeOptions(request.Options)
 		if err != nil {
 			return nil, err
--- a/internal/modules/dnd/extract/npcinteractions/extractor_test.go
+++ b/internal/modules/dnd/extract/npcinteractions/extractor_test.go
@@ -17,14 +17,14 @@ import (
 )

 func TestExtractMapsEveryKindAndOrdersBySourcePosition(t *testing.T) {
-	client := &fakeInteractionsLLMClient{response: extractionResponse{Interactions: []interactionResponse{
-		{Name: "Other", Kind: "other", SourceRefs: interactionRefs(30, 30)},
-		{Name: "Opponent", Kind: "combat_opponent", SourceRefs: interactionRefs(20, 20)},
-		{Name: "Ally", Kind: "combat_ally", SourceRefs: interactionRefs(5, 5)},
-		{Name: "Speaker", Kind: "dialogue", SourceRefs: append(interactionRefs(2, 2), interactionRefs(2, 2)...)},
-		{Name: "Present", Kind: "noncombat_presence", SourceRefs: interactionRefs(7, 7)},
-		{Name: "Mentioned", Kind: "mentioned", SourceRefs: interactionRefs(10, 10)},
-		{Name: "Invalid", Kind: "unsupported", SourceRefs: interactionRefs(0, 0)},
+	client := &fakeInteractionsLLMClient{response: extractionResponse{Occurrences: []occurrenceResponse{
+		{NPCID: identity.DeriveID("Other"), Name: "Other", Kind: "other", SourceRefs: interactionRefs(30, 30)},
+		{NPCID: identity.DeriveID("Opponent"), Name: "Opponent", Kind: "combat_opponent", SourceRefs: interactionRefs(20, 20)},
+		{NPCID: identity.DeriveID("Ally"), Name: "Ally", Kind: "combat_ally", SourceRefs: interactionRefs(5, 5)},
+		{NPCID: identity.DeriveID("Speaker"), Name: "Speaker", Kind: "dialogue", SourceRefs: append(interactionRefs(2, 2), interactionRefs(2, 2)...)},
+		{NPCID: identity.DeriveID("Present"), Name: "Present", Kind: "noncombat_presence", SourceRefs: interactionRefs(7, 7)},
+		{NPCID: identity.DeriveID("Mentioned"), Name: "Mentioned", Kind: "mentioned", SourceRefs: interactionRefs(10, 10)},
+		{NPCID: identity.DeriveID("Invalid"), Name: "Invalid", Kind: "unsupported", SourceRefs: interactionRefs(0, 0)},
 	}}}
 	references := requiredRegistryReferences(t, "Mentioned", "Speaker", "Present", "Ally", "Opponent", "Other", "Invalid")
 	req := extractionRequest()
@@ -37,21 +37,21 @@ func TestExtractMapsEveryKindAndOrdersBySourcePosition(t *testing.T) {
 	if got := interactionNames(result.Value); !reflect.DeepEqual(got, []string{"Mentioned", "Speaker", "Present", "Ally", "Opponent", "Other", "Invalid"}) {
 		t.Fatalf("interaction order = %#v", got)
 	}
-	if got := interactionKinds(result.Value); !reflect.DeepEqual(got, []dnd.NPCInteractionKind{
-		dnd.NPCInteractionKindMentioned,
-		dnd.NPCInteractionKindDialogue,
-		dnd.NPCInteractionKindNoncombatPresence,
-		dnd.NPCInteractionKindCombatAlly,
-		dnd.NPCInteractionKindCombatOpponent,
-		dnd.NPCInteractionKindOther,
+	if got := interactionKinds(result.Value); !reflect.DeepEqual(got, []dnd.NPCOccurrenceKind{
+		dnd.NPCOccurrenceKindMentioned,
+		dnd.NPCOccurrenceKindDialogue,
+		dnd.NPCOccurrenceKindNoncombatPresence,
+		dnd.NPCOccurrenceKindCombatAlly,
+		dnd.NPCOccurrenceKindCombatOpponent,
+		dnd.NPCOccurrenceKindOther,
 		"unsupported",
 	}) {
 		t.Fatalf("interaction kinds = %#v", got)
 	}
-	if refs := result.Value.Interactions[1].SourceRefs; !reflect.DeepEqual(refs, []source.SourceRef{{SourceID: "session-alpha", StartUnitID: 2, EndUnitID: 2}}) {
+	if refs := result.Value.Occurrences[1].SourceRefs; !reflect.DeepEqual(refs, []source.SourceRef{{SourceID: "session-alpha", StartUnitID: 2, EndUnitID: 2}}) {
 		t.Fatalf("canonical source refs = %#v", refs)
 	}
-	if invalid := result.Value.Interactions[6]; invalid.Name != "Invalid" || invalid.Kind != "unsupported" || !reflect.DeepEqual(invalid.SourceRefs, []source.SourceRef{{SourceID: "session-alpha"}}) {
+	if invalid := result.Value.Occurrences[6]; invalid.Name != "Invalid" || invalid.Kind != "unsupported" || !reflect.DeepEqual(invalid.SourceRefs, []source.SourceRef{{SourceID: "session-alpha"}}) {
 		t.Fatalf("invalid candidate = %#v, want preserved values with current source identity", invalid)
 	}
 	if len(client.requests) != 1 {
@@ -60,15 +60,15 @@ func TestExtractMapsEveryKindAndOrdersBySourcePosition(t *testing.T) {
 }

 func TestExtractUsesDocumentOrderForReferencesAndInteractions(t *testing.T) {
-	client := &fakeInteractionsLLMClient{response: extractionResponse{Interactions: []interactionResponse{
-		{Name: "Later", Kind: "dialogue", SourceRefs: interactionRefs(10, 10)},
-		{Name: "First", Kind: "mentioned", SourceRefs: []interactionSourceRefResponse{
+	client := &fakeInteractionsLLMClient{response: extractionResponse{Occurrences: []occurrenceResponse{
+		{NPCID: identity.DeriveID("Later"), Name: "Later", Kind: "dialogue", SourceRefs: interactionRefs(10, 10)},
+		{NPCID: identity.DeriveID("First"), Name: "First", Kind: "mentioned", SourceRefs: []interactionSourceRefResponse{
 			{StartUnitID: 10, EndUnitID: 10},
 			{StartUnitID: 30, EndUnitID: 30},
 			{StartUnitID: 30, EndUnitID: 30},
 			{StartUnitID: 999, EndUnitID: 0},
 		}},
-		{Name: "Second", Kind: "other", SourceRefs: interactionRefs(30, 30)},
+		{NPCID: identity.DeriveID("Second"), Name: "Second", Kind: "other", SourceRefs: interactionRefs(30, 30)},
 	}}}
 	references := requiredRegistryReferences(t, "Later", "First", "Second")
 	req := extractionRequest()
@@ -84,12 +84,12 @@ func TestExtractUsesDocumentOrderForReferencesAndInteractions(t *testing.T) {
 	if got := interactionNames(result.Value); !reflect.DeepEqual(got, []string{"First", "Second", "Later"}) {
 		t.Fatalf("interaction order = %#v, want document chronology with stable equal-evidence ties", got)
 	}
-	refs := result.Value.Interactions[0].SourceRefs
+	refs := result.Value.Occurrences[0].SourceRefs
 	if got := []int{refs[0].StartUnitID, refs[1].StartUnitID, refs[2].StartUnitID}; !reflect.DeepEqual(got, []int{30, 10, 999}) {
 		t.Fatalf("source refs = %#v, want document order with exact duplicate removed", refs)
 	}
 	refs[0].StartUnitID = 777
-	for _, interaction := range client.response.Interactions {
+	for _, interaction := range client.response.Occurrences {
 		for _, ref := range interaction.SourceRefs {
 			if ref.StartUnitID == 777 {
 				t.Fatal("result source references alias the model response")
@@ -107,9 +107,9 @@ func TestNewRequiresLLMAndRejectsAmbiguousReferenceSets(t *testing.T) {
 	}
 }

-func TestExtractUsesNamesOnlyRegistryAndCurrentTranscriptEvidence(t *testing.T) {
-	client := &fakeInteractionsLLMClient{response: extractionResponse{Interactions: []interactionResponse{{
-		Name: "Mira Thorn", Kind: "dialogue", SourceRefs: interactionRefs(10, 10),
+func TestExtractUsesRegistryIDsAndCurrentTranscriptEvidence(t *testing.T) {
+	client := &fakeInteractionsLLMClient{response: extractionResponse{Occurrences: []occurrenceResponse{{
+		NPCID: identity.DeriveID("Mira Thorn"), Name: "Mira Thorn", Kind: "dialogue", SourceRefs: interactionRefs(10, 10),
 	}}}}
 	references := requiredRegistryReferences(t, "Mira Thorn", "Hooded Guard")
 	req := extractionRequest()
@@ -119,10 +119,10 @@ func TestExtractUsesNamesOnlyRegistryAndCurrentTranscriptEvidence(t *testing.T)
 	}
 	request := client.requests[0]
 	registry := request.Inputs[NPCRegistryReferenceSlot]
-	if registry.Name != NPCRegistryReferenceSlot || registry.MediaType != "application/json" || string(registry.Content) != `{"npcs":[{"name":"Mira Thorn"},{"name":"Hooded Guard"}]}` {
-		t.Fatalf("registry prompt input = %#v, want exact names-only projection", registry)
+	if registry.Name != NPCRegistryReferenceSlot || registry.MediaType != "application/json" || string(registry.Content) != `{"npcs":[{"id":"`+identity.DeriveID("Mira Thorn")+`","name":"Mira Thorn"},{"id":"`+identity.DeriveID("Hooded Guard")+`","name":"Hooded Guard"}]}` {
+		t.Fatalf("registry prompt input = %#v, want exact ID and name projection", registry)
 	}
-	for _, forbidden := range []string{"npc:sha256:", "other-session", "start_unit_id"} {
+	for _, forbidden := range []string{"other-session", "start_unit_id"} {
 		if strings.Contains(string(registry.Content), forbidden) {
 			t.Fatalf("registry prompt input leaked %q: %s", forbidden, registry.Content)
 		}
@@ -162,8 +162,29 @@ func TestExtractRequiresBoundRegistryBeforeLLMCall(t *testing.T) {
 	}
 }

+func TestExtractRejectsUnknownIDsAndMismatchedNames(t *testing.T) {
+	references := requiredRegistryReferences(t, "Mira Thorn")
+	for _, test := range []struct {
+		name       string
+		occurrence occurrenceResponse
+		want       string
+	}{
+		{"unknown ID", occurrenceResponse{NPCID: "npc:unknown", Name: "Mira Thorn", Kind: "dialogue", SourceRefs: interactionRefs(10, 10)}, "npc_id is not in the NPC registry"},
+		{"mismatched name", occurrenceResponse{NPCID: identity.DeriveID("Mira Thorn"), Name: "Hooded Guard", Kind: "dialogue", SourceRefs: interactionRefs(10, 10)}, "name does not match npc_id"},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			client := &fakeInteractionsLLMClient{response: extractionResponse{Occurrences: []occurrenceResponse{test.occurrence}}}
+			req := extractionRequest()
+			req.References = references
+			if _, err := newExtractor(t, client, references).Extract(context.Background(), req); err == nil || !strings.Contains(err.Error(), test.want) {
+				t.Fatalf("Extract() error = %v, want %q", err, test.want)
+			}
+		})
+	}
+}
+
 func TestExtractResolvesGeneratedRegistryAtOperationTime(t *testing.T) {
-	client := &fakeInteractionsLLMClient{response: extractionResponse{Interactions: []interactionResponse{}}}
+	client := &fakeInteractionsLLMClient{response: extractionResponse{Occurrences: []occurrenceResponse{}}}
 	references := requiredRegistryReferences(t, "Mira Thorn")
 	req := extractionRequest()
 	req.References = references
@@ -171,7 +192,7 @@ func TestExtractResolvesGeneratedRegistryAtOperationTime(t *testing.T) {
 	if _, err := extractor.Extract(context.Background(), req); err != nil {
 		t.Fatalf("Extract() error = %v", err)
 	}
-	if input := client.requests[0].Inputs[NPCRegistryReferenceSlot]; string(input.Content) != `{"npcs":[{"name":"Mira Thorn"}]}` || input.OriginURI != "" {
+	if input := client.requests[0].Inputs[NPCRegistryReferenceSlot]; string(input.Content) != `{"npcs":[{"id":"`+identity.DeriveID("Mira Thorn")+`","name":"Mira Thorn"}]}` || input.OriginURI != "" {
 		t.Fatalf("generated registry prompt input = %#v", input)
 	}
 	metadata := extractor.ManifestMetadata()
@@ -191,11 +212,11 @@ func TestExtractAcceptsEmptyBoundRegistryAndEmptyResponse(t *testing.T) {
 			Items: []contracts.ReferenceItem{{SlotName: NPCRegistryReferenceSlot, MediaType: npccodec.MediaType, Content: content}},
 		},
 	}}
-	client := &fakeInteractionsLLMClient{response: extractionResponse{Interactions: []interactionResponse{}}}
+	client := &fakeInteractionsLLMClient{response: extractionResponse{Occurrences: []occurrenceResponse{}}}
 	req := extractionRequest()
 	req.References = references
 	result, err := newExtractor(t, client, references).Extract(context.Background(), req)
-	if err != nil || result.Value.Interactions == nil || len(result.Value.Interactions) != 0 {
+	if err != nil || result.Value.Occurrences == nil || len(result.Value.Occurrences) != 0 {
 		t.Fatalf("Extract() = %#v, %v; want present empty interactions", result, err)
 	}
 }
@@ -230,7 +251,7 @@ func TestExtractRejectsInvalidRequestsAndProviderFailures(t *testing.T) {

 func TestModuleSpecRegistrationMetadataAndFingerprints(t *testing.T) {
 	got := ModuleSpec()
-	if got.Key != Key || got.Stage != pipeline.StageExtract || got.ArtifactKind != dnd.NPCInteractionListKind || !reflect.DeepEqual(got.Requires, []string{"chunks", "source.transcript"}) || !reflect.DeepEqual(got.Provides, []string{"dnd.npc_interactions"}) {
+	if got.Key != Key || got.Stage != pipeline.StageExtract || got.ArtifactKind != dnd.NPCOccurrenceListKind || !reflect.DeepEqual(got.Requires, []string{"chunks", "source.transcript"}) || !reflect.DeepEqual(got.Provides, []string{"dnd.npc_interactions"}) {
 		t.Fatalf("ModuleSpec() = %#v", got)
 	}
 	var registrySlot contracts.ReferenceSlot
@@ -342,17 +363,17 @@ func interactionRefs(start, end int) []interactionSourceRefResponse {
 	return []interactionSourceRefResponse{{StartUnitID: start, EndUnitID: end}}
 }

-func interactionNames(value dnd.NPCInteractionList) []string {
-	names := make([]string, len(value.Interactions))
-	for index, interaction := range value.Interactions {
+func interactionNames(value dnd.NPCOccurrenceList) []string {
+	names := make([]string, len(value.Occurrences))
+	for index, interaction := range value.Occurrences {
 		names[index] = interaction.Name
 	}
 	return names
 }

-func interactionKinds(value dnd.NPCInteractionList) []dnd.NPCInteractionKind {
-	kinds := make([]dnd.NPCInteractionKind, len(value.Interactions))
-	for index, interaction := range value.Interactions {
+func interactionKinds(value dnd.NPCOccurrenceList) []dnd.NPCOccurrenceKind {
+	kinds := make([]dnd.NPCOccurrenceKind, len(value.Occurrences))
+	for index, interaction := range value.Occurrences {
 		kinds[index] = interaction.Kind
 	}
 	return kinds
--- a/internal/modules/dnd/extract/npcinteractions/model.go
+++ b/internal/modules/dnd/extract/npcinteractions/model.go
@@ -1,10 +1,11 @@
 package npcinteractions

 type extractionResponse struct {
-	Interactions []interactionResponse `json:"interactions"`
+	Occurrences []occurrenceResponse `json:"occurrences"`
 }

-type interactionResponse struct {
+type occurrenceResponse struct {
+	NPCID      string                         `json:"npc_id"`
 	Name       string                         `json:"name"`
 	Kind       string                         `json:"kind"`
 	SourceRefs []interactionSourceRefResponse `json:"source_refs"`
--- a/internal/modules/dnd/extract/npcinteractions/model_test.go
+++ b/internal/modules/dnd/extract/npcinteractions/model_test.go
@@ -6,13 +6,13 @@ import (
 )

 func TestExtractionResponsePreservesValidatorOwnedSemantics(t *testing.T) {
-	content := []byte(`{"interactions":[{"name":"","kind":"unsupported","source_refs":[{"start_unit_id":0,"end_unit_id":-1}]}]}`)
+	content := []byte(`{"occurrences":[{"npc_id":"","name":"","kind":"unsupported","source_refs":[{"start_unit_id":0,"end_unit_id":-1}]}]}`)
 	var response extractionResponse
 	if err := json.Unmarshal(content, &response); err != nil {
 		t.Fatalf("json.Unmarshal() error = %v", err)
 	}
-	interaction := response.Interactions[0]
-	if interaction.Name != "" || interaction.Kind != "unsupported" || interaction.SourceRefs[0] != (interactionSourceRefResponse{StartUnitID: 0, EndUnitID: -1}) {
-		t.Fatalf("decoded response = %#v", interaction)
+	occurrence := response.Occurrences[0]
+	if occurrence.NPCID != "" || occurrence.Name != "" || occurrence.Kind != "unsupported" || occurrence.SourceRefs[0] != (interactionSourceRefResponse{StartUnitID: 0, EndUnitID: -1}) {
+		t.Fatalf("decoded response = %#v", occurrence)
 	}
 }
--- a/internal/modules/dnd/extract/npcinteractions/prompt_assets_test.go
+++ b/internal/modules/dnd/extract/npcinteractions/prompt_assets_test.go
@@ -20,7 +20,7 @@ func TestRegisterPromptAssetsAndPrepareInteractionPrompt(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if _, err := fs.ReadFile(schemaFS, "dnd_npc_interactions_llm.v1.json"); err != nil {
+	if _, err := fs.ReadFile(schemaFS, "dnd_npc_occurrences_llm.v1.json"); err != nil {
 		t.Fatalf("response schema asset: %v", err)
 	}
 	options, err := registry.PromptKitOptions()
@@ -42,13 +42,13 @@ func TestRegisterPromptAssetsAndPrepareInteractionPrompt(t *testing.T) {
 			"players":      promptkit.Inline("interaction-player"),
 			"party":        promptkit.Inline("Mira: ranger"),
 			"glossary":     promptkit.Inline("Greencloak: title"),
-			"npc_registry": promptkit.Inline(`{"npcs":[{"name":"interaction-npc"}]}`),
+			"npc_registry": promptkit.Inline(`{"npcs":[{"id":"npc:sha256:test","name":"interaction-npc"}]}`),
 		},
 	})
 	if err != nil {
 		t.Fatal(err)
 	}
-	if prepared.PromptID != PromptID || prepared.OutputContract.SchemaPath != "dnd_npc_interactions_llm.v1.json" {
+	if prepared.PromptID != PromptID || prepared.OutputContract.SchemaPath != "dnd_npc_occurrences_llm.v1.json" {
 		t.Fatalf("prepared prompt = %#v", prepared)
 	}
 }
@@ -59,7 +59,7 @@ func TestPromptMetadataDoesNotExposeAssetContent(t *testing.T) {
 		t.Fatalf("promptAssetMetadata() = %q, %v", hash, err)
 	}
 	metadata := newExtractor(t, &fakeInteractionsLLMClient{}).ManifestMetadata()
-	for _, forbidden := range []string{"common-dnd-system", "dnd_npc_interactions_llm.v1.json"} {
+	for _, forbidden := range []string{"common-dnd-system", "dnd_npc_occurrences_llm.v1.json"} {
 		if strings.Contains(strings.Join(mapValues(metadata), " "), forbidden) {
 			t.Fatalf("metadata leaked prompt or schema content %q: %#v", forbidden, metadata)
 		}
--- a/internal/modules/dnd/extract/npcinteractions/schema.go
+++ b/internal/modules/dnd/extract/npcinteractions/schema.go
@@ -4,9 +4,9 @@ import "gitea.maximumdirect.net/eric/notarius/internal/framework/llm"

 const (
 	PromptID           = "dnd.npc_interactions"
-	ResponseSchemaKey  = llm.ResponseSchemaKey("dnd_npc_interactions_llm")
-	ResponseSchemaID   = "notarius.dnd.npc_interactions.llm"
-	ResponseSchemaName = "notarius_dnd_npc_interactions_llm_v1"
+	ResponseSchemaKey  = llm.ResponseSchemaKey("dnd_npc_occurrences_llm")
+	ResponseSchemaID   = "notarius.dnd.npc_occurrences.llm"
+	ResponseSchemaName = "notarius_dnd_npc_occurrences_llm_v1"
 	SchemaVersion      = "v1"
 )

@@ -20,6 +20,6 @@ func loadResponseSchema() (llm.ResponseSchema, error) {
 		ID:        ResponseSchemaID,
 		Version:   SchemaVersion,
 		Name:      ResponseSchemaName,
-		AssetPath: "schemas/dnd_npc_interactions_llm.v1.json",
+		AssetPath: "schemas/dnd_npc_occurrences_llm.v1.json",
 	})
 }
--- a/internal/modules/dnd/extract/npcinteractions/schema_test.go
+++ b/internal/modules/dnd/extract/npcinteractions/schema_test.go
@@ -27,7 +27,7 @@ func TestResponseSchemaOwnsOnlyPrivateStructuralContract(t *testing.T) {
 	}

 	semanticCandidate := validInteractionResponse()
-	interaction := semanticCandidate["interactions"].([]any)[0].(map[string]any)
+	interaction := semanticCandidate["occurrences"].([]any)[0].(map[string]any)
 	interaction["name"] = ""
 	interaction["kind"] = "unsupported"
 	ref := interaction["source_refs"].([]any)[0].(map[string]any)
@@ -42,6 +42,7 @@ func TestResponseSchemaOwnsOnlyPrivateStructuralContract(t *testing.T) {
 	}

 	for _, mutate := range []func(map[string]any){
+		func(record map[string]any) { delete(record, "npc_id") },
 		func(record map[string]any) { delete(record, "name") },
 		func(record map[string]any) { record["kind"] = 1 },
 		func(record map[string]any) { record["unexpected"] = true },
@@ -50,7 +51,7 @@ func TestResponseSchemaOwnsOnlyPrivateStructuralContract(t *testing.T) {
 		},
 	} {
 		candidate := validInteractionResponse()
-		mutate(candidate["interactions"].([]any)[0].(map[string]any))
+		mutate(candidate["occurrences"].([]any)[0].(map[string]any))
 		content, err := json.Marshal(candidate)
 		if err != nil {
 			t.Fatal(err)
@@ -79,8 +80,8 @@ func TestResponseSchemaIsDefensiveAndContentSafe(t *testing.T) {
 }

 func validInteractionResponse() map[string]any {
-	return map[string]any{"interactions": []any{map[string]any{
-		"name": "Mira Thorn", "kind": "dialogue",
+	return map[string]any{"occurrences": []any{map[string]any{
+		"npc_id": "npc:sha256:test", "name": "Mira Thorn", "kind": "dialogue",
 		"source_refs": []any{map[string]any{"start_unit_id": 1, "end_unit_id": 2}},
 	}}}
 }
--- a/internal/modules/dnd/normalize/npcinteractions/normalizer.go
+++ b/internal/modules/dnd/normalize/npcinteractions/normalizer.go
@@ -11,7 +11,6 @@ import (
 	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
 	interactionmodel "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcinteractions"
-	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcs/identity"
 	npcregistry "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcs/registry"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared/diagnostics"
@@ -22,7 +21,6 @@ const (
 	normalizationPolicy = "dnd.npc_interactions.normalize.v2"
 	NormalizationPolicy = normalizationPolicy

-	ReasonCodeNameCanonicalized     = "npc_interaction_name_canonicalized"
 	ReasonCodeSourceRefsNormalized  = "source_references_normalized"
 	ReasonCodeInteractionsReordered = "npc_interactions_reordered"
 	ReasonCodeDuplicateCollapsed    = "duplicate_npc_interaction_collapsed"
@@ -44,7 +42,7 @@ var referenceSlotDescriptions = shared.ReferenceSlotDescriptions{
 	Roster:   "Deprecated alias for party roster reference material used only for interaction disambiguation.",
 }

-var _ contracts.Normalizer[dnd.NPCInteractionList] = (*Normalizer)(nil)
+var _ contracts.Normalizer[dnd.NPCOccurrenceList] = (*Normalizer)(nil)
 var _ contracts.ManifestMetadataProvider = (*Normalizer)(nil)
 var _ pipeline.CheckpointFingerprintProvider = (*Normalizer)(nil)

@@ -79,7 +77,6 @@ func (n *Normalizer) ManifestMetadata() map[string]any {
 	}
 	metadata := map[string]any{
 		"normalization_policy": normalizationPolicy,
-		"identity_policy":      identity.Policy,
 	}
 	seeded := n.npcResolver.Seeded()
 	if seeded.Bound() {
@@ -95,82 +92,74 @@ func (n *Normalizer) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
 	}
 	return []pipeline.CheckpointFingerprint{
 		{Name: "normalization_policy", Value: normalizationPolicy},
-		{Name: "identity_policy", Value: identity.Policy},
-		{Name: "npc_registry", Value: n.npcResolver.Seeded().ProjectionDigest()},
+		{Name: "npc_registry", Value: n.npcResolver.Seeded().IdentityPromptInput().Digest},
 	}
 }

-func (n *Normalizer) Normalize(ctx context.Context, req contracts.TypedNormalizeRequest[dnd.NPCInteractionList]) (contracts.TypedNormalizeResult[dnd.NPCInteractionList], error) {
+func (n *Normalizer) Normalize(ctx context.Context, req contracts.TypedNormalizeRequest[dnd.NPCOccurrenceList]) (contracts.TypedNormalizeResult[dnd.NPCOccurrenceList], error) {
 	if n == nil || n.npcResolver == nil {
-		return contracts.TypedNormalizeResult[dnd.NPCInteractionList]{}, normalizerErrorf("normalizer must not be nil")
+		return contracts.TypedNormalizeResult[dnd.NPCOccurrenceList]{}, normalizerErrorf("normalizer must not be nil")
 	}
 	if ctx == nil {
-		return contracts.TypedNormalizeResult[dnd.NPCInteractionList]{}, normalizerErrorf("context must not be nil")
+		return contracts.TypedNormalizeResult[dnd.NPCOccurrenceList]{}, normalizerErrorf("context must not be nil")
 	}
 	if err := ctx.Err(); err != nil {
-		return contracts.TypedNormalizeResult[dnd.NPCInteractionList]{}, normalizerErrorf("context error before normalize: %w", err)
+		return contracts.TypedNormalizeResult[dnd.NPCOccurrenceList]{}, normalizerErrorf("context error before normalize: %w", err)
 	}

 	registry, err := n.npcResolver.Resolve(req.References)
 	if err != nil {
-		return contracts.TypedNormalizeResult[dnd.NPCInteractionList]{}, normalizerErrorf("resolve NPC registry: %w", err)
+		return contracts.TypedNormalizeResult[dnd.NPCOccurrenceList]{}, normalizerErrorf("resolve NPC registry: %w", err)
 	}
 	if !registry.Bound() {
-		return contracts.TypedNormalizeResult[dnd.NPCInteractionList]{}, normalizerErrorf("NPC registry reference is required")
+		return contracts.TypedNormalizeResult[dnd.NPCOccurrenceList]{}, normalizerErrorf("NPC registry reference is required")
 	}
 	index := source.NewDocumentIndex(req.Source)
 	order := shared.NewSourceRefOrderFromIndex(index)
-	value, warnings := normalizeList(req.MergeOutput.Value, index, order, registry)
-	return contracts.TypedNormalizeResult[dnd.NPCInteractionList]{Value: value, Warnings: warnings}, nil
+	value, warnings, err := normalizeList(req.MergeOutput.Value, index, order, registry)
+	if err != nil {
+		return contracts.TypedNormalizeResult[dnd.NPCOccurrenceList]{}, normalizerErrorf("validate NPC registry pairs: %w", err)
+	}
+	return contracts.TypedNormalizeResult[dnd.NPCOccurrenceList]{Value: value, Warnings: warnings}, nil
 }

 type normalizedRecord struct {
-	interaction dnd.NPCInteraction
-	inputIndex  int
+	occurrence dnd.NPCOccurrence
+	inputIndex int
 }

-type nameCanonicalization struct {
-	from string
-	to   string
-}
-
-func normalizeList(input dnd.NPCInteractionList, documentIndex source.DocumentIndex, order shared.SourceRefOrder, registry *npcregistry.Registry) (dnd.NPCInteractionList, []contracts.Warning) {
-	if input.Interactions == nil {
-		return dnd.NPCInteractionList{}, nil
+func normalizeList(input dnd.NPCOccurrenceList, documentIndex source.DocumentIndex, order shared.SourceRefOrder, registry *npcregistry.Registry) (dnd.NPCOccurrenceList, []contracts.Warning, error) {
+	if input.Occurrences == nil {
+		return dnd.NPCOccurrenceList{}, nil, nil
 	}

-	records := make([]normalizedRecord, len(input.Interactions))
+	records := make([]normalizedRecord, len(input.Occurrences))
 	warnings := make([]contracts.Warning, 0)
-	for index, inputInteraction := range input.Interactions {
-		interaction, nameChange, refsChanged := normalizeInteraction(inputInteraction, order, registry)
-		records[index] = normalizedRecord{interaction: interaction, inputIndex: index}
-		if nameChange != nil {
-			warnings = append(warnings, contracts.Warning{
-				Scope:      interactionScope(index),
-				ReasonCode: ReasonCodeNameCanonicalized,
-				Message: fmt.Sprintf("input index %d: NPC name canonicalized from %s to %s",
-					index, diagnostics.Quote(nameChange.from), diagnostics.Quote(nameChange.to)),
-			})
+	for index, inputOccurrence := range input.Occurrences {
+		occurrence, refsChanged, err := normalizeOccurrence(inputOccurrence, order, registry)
+		if err != nil {
+			return dnd.NPCOccurrenceList{}, nil, fmt.Errorf("occurrences[%d]: %w", index, err)
 		}
+		records[index] = normalizedRecord{occurrence: occurrence, inputIndex: index}
 		if refsChanged {
 			warnings = append(warnings, contracts.Warning{
-				Scope:      interactionScope(index),
+				Scope:      occurrenceScope(index),
 				ReasonCode: ReasonCodeSourceRefsNormalized,
 				Message: fmt.Sprintf("input index %d: source references normalized (original count %d, final count %d)",
-					index, len(inputInteraction.SourceRefs), len(interaction.SourceRefs)),
+					index, len(inputOccurrence.SourceRefs), len(occurrence.SourceRefs)),
 			})
 		}
 	}

 	sort.SliceStable(records, func(left, right int) bool {
-		return interactionmodel.Less(order, records[left].interaction, records[right].interaction)
+		return interactionmodel.Less(order, records[left].occurrence, records[right].occurrence)
 	})
 	for position, record := range records {
 		if position == record.inputIndex {
 			continue
 		}
 		warnings = append(warnings, contracts.Warning{
-			Scope:      interactionScope(record.inputIndex),
+			Scope:      occurrenceScope(record.inputIndex),
 			ReasonCode: ReasonCodeInteractionsReordered,
 			Message:    fmt.Sprintf("input index %d moved to normalized position %d by source chronology", record.inputIndex, position),
 		})
@@ -178,24 +167,24 @@ func normalizeList(input dnd.NPCInteractionList, documentIndex source.DocumentIn

 	output, duplicateWarnings := collapseDuplicates(records, documentIndex)
 	warnings = append(warnings, duplicateWarnings...)
-	return dnd.NPCInteractionList{Interactions: output},
-		diagnostics.LimitWarnings(warnings, "npc_interactions", ReasonCodeWarningsOmitted)
+	return dnd.NPCOccurrenceList{Occurrences: output},
+		diagnostics.LimitWarnings(warnings, "npc_interactions", ReasonCodeWarningsOmitted), nil
 }

-func normalizeInteraction(input dnd.NPCInteraction, order shared.SourceRefOrder, registry *npcregistry.Registry) (dnd.NPCInteraction, *nameCanonicalization, bool) {
-	output := cloneInteraction(input)
-	if canonical, ok := registry.Lookup(identity.NormalizeDisplay(input.Name)); ok {
-		output.Name = canonical.Name
+func normalizeOccurrence(input dnd.NPCOccurrence, order shared.SourceRefOrder, registry *npcregistry.Registry) (dnd.NPCOccurrence, bool, error) {
+	canonical, ok := registry.LookupID(input.NPCID)
+	if !ok {
+		return dnd.NPCOccurrence{}, false, fmt.Errorf("npc_id is not in the NPC registry")
 	}
-	var nameChange *nameCanonicalization
-	if input.Name != output.Name {
-		nameChange = &nameCanonicalization{from: input.Name, to: output.Name}
+	if input.Name != canonical.Name {
+		return dnd.NPCOccurrence{}, false, fmt.Errorf("name does not match npc_id")
 	}
+	output := cloneOccurrence(input)
 	output.SourceRefs = order.Canonicalize(input.SourceRefs)
-	return output, nameChange, !interactionmodel.SourceRefsEqual(input.SourceRefs, output.SourceRefs)
+	return output, !interactionmodel.SourceRefsEqual(input.SourceRefs, output.SourceRefs), nil
 }

-func cloneInteraction(input dnd.NPCInteraction) dnd.NPCInteraction {
+func cloneOccurrence(input dnd.NPCOccurrence) dnd.NPCOccurrence {
 	output := input
 	if input.SourceRefs != nil {
 		output.SourceRefs = append([]source.SourceRef(nil), input.SourceRefs...)
@@ -208,19 +197,19 @@ type duplicateGroup struct {
 	removed       []int
 }

-func collapseDuplicates(records []normalizedRecord, documentIndex source.DocumentIndex) ([]dnd.NPCInteraction, []contracts.Warning) {
+func collapseDuplicates(records []normalizedRecord, documentIndex source.DocumentIndex) ([]dnd.NPCOccurrence, []contracts.Warning) {
 	if len(records) == 0 {
-		return make([]dnd.NPCInteraction, 0), nil
+		return make([]dnd.NPCOccurrence, 0), nil
 	}
 	keep := make([]bool, len(records))
 	groups := make([]duplicateGroup, 0)
 	groupByKey := make(map[string]int)
 	for index, record := range records {
-		if !interactionmodel.ValidSourceRefs(documentIndex, record.interaction.SourceRefs) {
+		if !interactionmodel.ValidSourceRefs(documentIndex, record.occurrence.SourceRefs) {
 			keep[index] = true
 			continue
 		}
-		key := interactionmodel.ExactIdentity(record.interaction)
+		key := interactionmodel.ExactIdentity(record.occurrence)
 		groupIndex, exists := groupByKey[key]
 		if !exists {
 			groupByKey[key] = len(groups)
@@ -230,10 +219,10 @@ func collapseDuplicates(records []normalizedRecord, documentIndex source.Documen
 		}
 		groups[groupIndex].removed = append(groups[groupIndex].removed, record.inputIndex)
 	}
-	output := make([]dnd.NPCInteraction, 0, len(records))
+	output := make([]dnd.NPCOccurrence, 0, len(records))
 	for index, record := range records {
 		if keep[index] {
-			output = append(output, cloneInteraction(record.interaction))
+			output = append(output, cloneOccurrence(record.occurrence))
 		}
 	}
 	warnings := make([]contracts.Warning, 0)
@@ -251,14 +240,14 @@ func duplicateWarning(retainedIndex int, removed []int) contracts.Warning {
 		issues[index] = fmt.Sprintf("removed input index %d", removedIndex)
 	}
 	return contracts.Warning{
-		Scope:      interactionScope(retainedIndex),
+		Scope:      occurrenceScope(retainedIndex),
 		ReasonCode: ReasonCodeDuplicateCollapsed,
 		Message: diagnostics.Aggregate(
 			fmt.Sprintf("duplicate NPC interaction collapsed; retained input index %d", retainedIndex), issues),
 	}
 }

-func interactionScope(index int) string { return fmt.Sprintf("interactions[%d]", index) }
+func occurrenceScope(index int) string { return fmt.Sprintf("occurrences[%d]", index) }

 func referenceSlots() []contracts.ReferenceSlot {
 	slots := shared.ReferenceSlots(referenceSlotDescriptions)
@@ -281,13 +270,13 @@ func ModuleSpec() pipeline.ModuleSpec {
 		ExecutionClass: contracts.ExecutionClassDeterministic,
 		Requires:       append([]string(nil), requiredCapabilities...),
 		Provides:       append([]string(nil), providedCapabilities...),
-		ArtifactKind:   dnd.NPCInteractionListKind,
+		ArtifactKind:   dnd.NPCOccurrenceListKind,
 		ReferenceSlots: referenceSlots(),
 	}
 }

 func Register(registry *pipeline.NormalizerRegistry) error {
-	return pipeline.RegisterNormalizerBuilder(registry, ModuleSpec(), validateOptions, func(request pipeline.BuildRequest) (contracts.Normalizer[dnd.NPCInteractionList], error) {
+	return pipeline.RegisterNormalizerBuilder(registry, ModuleSpec(), validateOptions, func(request pipeline.BuildRequest) (contracts.Normalizer[dnd.NPCOccurrenceList], error) {
 		options, err := DecodeOptions(request.Options)
 		if err != nil {
 			return nil, err
--- a/internal/modules/dnd/normalize/npcinteractions/normalizer_test.go
+++ b/internal/modules/dnd/normalize/npcinteractions/normalizer_test.go
@@ -14,37 +14,37 @@ import (
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared/diagnostics"
 )

-func TestNormalizeCanonicalizesAndClones(t *testing.T) {
+func TestNormalizeValidatesPairsAndClones(t *testing.T) {
 	doc := &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 30}, {ID: 10}}}
 	normalizer, err := New(Options{}, npcReferences(t))
 	if err != nil {
 		t.Fatalf("New() error = %v", err)
 	}
-	input := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{
-		Name: "  áRIA  ", Kind: dnd.NPCInteractionKindDialogue,
+	input := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{
+		NPCID: identity.DeriveID("Ária"), Name: "Ária", Kind: dnd.NPCOccurrenceKindDialogue,
 		SourceRefs: []source.SourceRef{{SourceID: doc.ID, StartUnitID: 30, EndUnitID: 30}, {SourceID: doc.ID, StartUnitID: 10, EndUnitID: 10}, {SourceID: doc.ID, StartUnitID: 30, EndUnitID: 30}},
 	}}}
-	original := append([]source.SourceRef(nil), input.Interactions[0].SourceRefs...)
-	result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCInteractionList]{Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCInteractionList]{Value: input}})
+	original := append([]source.SourceRef(nil), input.Occurrences[0].SourceRefs...)
+	result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCOccurrenceList]{Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCOccurrenceList]{Value: input}})
 	if err != nil {
 		t.Fatalf("Normalize() error = %v", err)
 	}
-	got := result.Value.Interactions[0]
-	if got.Name != "Ária" || !reflect.DeepEqual(got.SourceRefs, []source.SourceRef{{SourceID: doc.ID, StartUnitID: 30, EndUnitID: 30}, {SourceID: doc.ID, StartUnitID: 10, EndUnitID: 10}}) {
+	got := result.Value.Occurrences[0]
+	if got.NPCID != identity.DeriveID("Ária") || got.Name != "Ária" || !reflect.DeepEqual(got.SourceRefs, []source.SourceRef{{SourceID: doc.ID, StartUnitID: 30, EndUnitID: 30}, {SourceID: doc.ID, StartUnitID: 10, EndUnitID: 10}}) {
 		t.Fatalf("normalized interaction = %#v", got)
 	}
-	if !hasWarning(result.Warnings, ReasonCodeNameCanonicalized) || !hasWarning(result.Warnings, ReasonCodeSourceRefsNormalized) {
+	if !hasWarning(result.Warnings, ReasonCodeSourceRefsNormalized) {
 		t.Fatalf("warnings = %#v", result.Warnings)
 	}
-	if !reflect.DeepEqual(input.Interactions[0].SourceRefs, original) {
+	if !reflect.DeepEqual(input.Occurrences[0].SourceRefs, original) {
 		t.Fatalf("Normalize() mutated input: %#v", input)
 	}
-	second, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCInteractionList]{Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCInteractionList]{Value: result.Value}})
+	second, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCOccurrenceList]{Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCOccurrenceList]{Value: result.Value}})
 	if err != nil || !reflect.DeepEqual(second.Value, result.Value) || len(second.Warnings) != 0 {
 		t.Fatalf("second normalization = %#v, %v; want idempotent output without warnings", second, err)
 	}
-	result.Value.Interactions[0].SourceRefs[0].StartUnitID = 999
-	if input.Interactions[0].SourceRefs[0].StartUnitID == 999 {
+	result.Value.Occurrences[0].SourceRefs[0].StartUnitID = 999
+	if input.Occurrences[0].SourceRefs[0].StartUnitID == 999 {
 		t.Fatal("normalized source refs share input storage")
 	}
 }
@@ -54,14 +54,14 @@ func TestNormalizeRequiresOperationRegistryAndPreservesEmptyRepresentation(t *te
 	if err != nil {
 		t.Fatalf("New() error = %v", err)
 	}
-	if _, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCInteractionList]{}); err == nil {
+	if _, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCOccurrenceList]{}); err == nil {
 		t.Fatal("Normalize() accepted an unbound NPC registry")
 	}
-	for _, input := range []dnd.NPCInteractionList{{}, {Interactions: []dnd.NPCInteraction{}}} {
-		result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCInteractionList]{
-			MergeOutput: contracts.MergeArtifact[dnd.NPCInteractionList]{Value: input}, References: npcReferences(t),
+	for _, input := range []dnd.NPCOccurrenceList{{}, {Occurrences: []dnd.NPCOccurrence{}}} {
+		result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCOccurrenceList]{
+			MergeOutput: contracts.MergeArtifact[dnd.NPCOccurrenceList]{Value: input}, References: npcReferences(t),
 		})
-		if err != nil || (result.Value.Interactions == nil) != (input.Interactions == nil) {
+		if err != nil || (result.Value.Occurrences == nil) != (input.Occurrences == nil) {
 			t.Fatalf("Normalize() = %#v, %v for input %#v", result, err, input)
 		}
 	}
@@ -70,16 +70,20 @@ func TestNormalizeRequiresOperationRegistryAndPreservesEmptyRepresentation(t *te
 	}
 }

-func TestNormalizeLeavesUnrecognizedNamesUntouched(t *testing.T) {
+func TestNormalizeRejectsUnknownIDsAndMismatchedNames(t *testing.T) {
 	doc := testDocument()
 	normalizer, err := New(Options{}, npcReferences(t))
 	if err != nil {
 		t.Fatal(err)
 	}
-	input := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{interaction("  Unknown NPC  ", dnd.NPCInteractionKindOther, source.SourceRef{SourceID: doc.ID, StartUnitID: 10, EndUnitID: 10})}}
-	result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCInteractionList]{Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCInteractionList]{Value: input}})
-	if err != nil || result.Value.Interactions[0].Name != input.Interactions[0].Name || hasWarning(result.Warnings, ReasonCodeNameCanonicalized) {
-		t.Fatalf("Normalize() = %#v, %v; want untouched unrecognized name", result, err)
+	for _, occurrence := range []dnd.NPCOccurrence{
+		interaction("Unknown NPC", dnd.NPCOccurrenceKindOther, source.SourceRef{SourceID: doc.ID, StartUnitID: 10, EndUnitID: 10}),
+		{NPCID: identity.DeriveID("Ária"), Name: "Borin", Kind: dnd.NPCOccurrenceKindOther, SourceRefs: []source.SourceRef{{SourceID: doc.ID, StartUnitID: 10, EndUnitID: 10}}},
+	} {
+		input := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{occurrence}}
+		if result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCOccurrenceList]{Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCOccurrenceList]{Value: input}}); err == nil {
+			t.Fatalf("Normalize() = %#v, %v; want registry pair rejection", result, err)
+		}
 	}
 }

@@ -88,28 +92,28 @@ func TestNormalizeOrdersAndCollapsesExactDuplicatesOnly(t *testing.T) {
 	ref := func(unit int) source.SourceRef {
 		return source.SourceRef{SourceID: doc.ID, StartUnitID: unit, EndUnitID: unit}
 	}
-	first := interaction("Ária", dnd.NPCInteractionKindDialogue, ref(50))
-	input := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{
-		interaction("Borin", dnd.NPCInteractionKindMentioned, ref(90)),
+	first := interaction("Ária", dnd.NPCOccurrenceKindDialogue, ref(50))
+	input := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{
+		interaction("Borin", dnd.NPCOccurrenceKindMentioned, ref(90)),
 		first,
 		first,
-		interaction("Ária", dnd.NPCInteractionKindCombatAlly, ref(50)),
-		interaction("Ária", dnd.NPCInteractionKindDialogue, ref(10)),
-		interaction("Ária", dnd.NPCInteractionKindDialogue, ref(999)),
+		interaction("Ária", dnd.NPCOccurrenceKindCombatAlly, ref(50)),
+		interaction("Ária", dnd.NPCOccurrenceKindDialogue, ref(10)),
+		interaction("Ária", dnd.NPCOccurrenceKindDialogue, ref(999)),
 	}}
 	normalizer, err := New(Options{}, npcReferences(t))
 	if err != nil {
 		t.Fatal(err)
 	}
-	result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCInteractionList]{Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCInteractionList]{Value: input}})
+	result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCOccurrenceList]{Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCOccurrenceList]{Value: input}})
 	if err != nil {
 		t.Fatal(err)
 	}
-	got := result.Value.Interactions
+	got := result.Value.Occurrences
 	if len(got) != 5 {
 		t.Fatalf("interaction count = %d, want 5: %#v", len(got), got)
 	}
-	if got[0].Kind != dnd.NPCInteractionKindCombatAlly || got[0].SourceRefs[0].StartUnitID != 50 || got[1].SourceRefs[0].StartUnitID != 50 || got[2].SourceRefs[0].StartUnitID != 10 || got[3].SourceRefs[0].StartUnitID != 90 || got[4].SourceRefs[0].StartUnitID != 999 {
+	if got[0].Kind != dnd.NPCOccurrenceKindCombatAlly || got[0].SourceRefs[0].StartUnitID != 50 || got[1].SourceRefs[0].StartUnitID != 50 || got[2].SourceRefs[0].StartUnitID != 10 || got[3].SourceRefs[0].StartUnitID != 90 || got[4].SourceRefs[0].StartUnitID != 999 {
 		t.Fatalf("canonical order = %#v", got)
 	}
 	if !hasWarning(result.Warnings, ReasonCodeInteractionsReordered) || !hasWarning(result.Warnings, ReasonCodeDuplicateCollapsed) {
@@ -122,13 +126,13 @@ func TestNormalizerContractAndDeterministicWarnings(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if spec := ModuleSpec(); spec.Key != Key || spec.Stage != pipeline.StageNormalize || spec.ArtifactKind != dnd.NPCInteractionListKind || len(spec.ReferenceSlots) == 0 {
+	if spec := ModuleSpec(); spec.Key != Key || spec.Stage != pipeline.StageNormalize || spec.ArtifactKind != dnd.NPCOccurrenceListKind || len(spec.ReferenceSlots) == 0 {
 		t.Fatalf("ModuleSpec() = %#v", spec)
 	}
-	if metadata := normalizer.ManifestMetadata(); metadata["normalization_policy"] != normalizationPolicy || metadata["identity_policy"] != identity.Policy || metadata["npc_registry_digest"] == "" || metadata["npc_count"] != 2 {
+	if metadata := normalizer.ManifestMetadata(); metadata["normalization_policy"] != normalizationPolicy || metadata["npc_registry_digest"] == "" || metadata["npc_count"] != 2 {
 		t.Fatalf("metadata = %#v", metadata)
 	}
-	if fingerprints := normalizer.CheckpointFingerprints(); len(fingerprints) != 3 || fingerprints[2].Name != "npc_registry" || fingerprints[2].Value == "" {
+	if fingerprints := normalizer.CheckpointFingerprints(); len(fingerprints) != 2 || fingerprints[1].Name != "npc_registry" || fingerprints[1].Value == "" {
 		t.Fatalf("fingerprints = %#v", fingerprints)
 	}
 	if _, err := DecodeOptions(map[string]any{"unexpected": true}); err == nil {
@@ -139,13 +143,13 @@ func TestNormalizerContractAndDeterministicWarnings(t *testing.T) {
 func TestNormalizeBoundsWarnings(t *testing.T) {
 	count := diagnostics.MaxWarnings + 5
 	doc := &source.SourceDocument{ID: "session", Units: make([]source.SourceUnit, count)}
-	input := dnd.NPCInteractionList{Interactions: make([]dnd.NPCInteraction, count)}
+	input := dnd.NPCOccurrenceList{Occurrences: make([]dnd.NPCOccurrence, count)}
 	for index := range doc.Units {
 		doc.Units[index].ID = index + 1
 		unitID := count - index
-		input.Interactions[index] = interaction(
+		input.Occurrences[index] = interaction(
 			"Ária",
-			dnd.NPCInteractionKindDialogue,
+			dnd.NPCOccurrenceKindDialogue,
 			source.SourceRef{SourceID: doc.ID, StartUnitID: unitID, EndUnitID: unitID},
 		)
 	}
@@ -153,8 +157,8 @@ func TestNormalizeBoundsWarnings(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCInteractionList]{
-		Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCInteractionList]{Value: input},
+	result, err := normalizer.Normalize(context.Background(), contracts.TypedNormalizeRequest[dnd.NPCOccurrenceList]{
+		Source: doc, MergeOutput: contracts.MergeArtifact[dnd.NPCOccurrenceList]{Value: input},
 	})
 	if err != nil {
 		t.Fatal(err)
@@ -165,8 +169,8 @@ func TestNormalizeBoundsWarnings(t *testing.T) {
 	}
 }

-func interaction(name string, kind dnd.NPCInteractionKind, ref source.SourceRef) dnd.NPCInteraction {
-	return dnd.NPCInteraction{Name: name, Kind: kind, SourceRefs: []source.SourceRef{ref}}
+func interaction(name string, kind dnd.NPCOccurrenceKind, ref source.SourceRef) dnd.NPCOccurrence {
+	return dnd.NPCOccurrence{NPCID: identity.DeriveID(name), Name: name, Kind: kind, SourceRefs: []source.SourceRef{ref}}
 }

 func testDocument() *source.SourceDocument {
--- a/internal/modules/dnd/npcinteractions/canonical.go
+++ b/internal/modules/dnd/npcinteractions/canonical.go
@@ -8,7 +8,6 @@ import (

 	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
-	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcs/identity"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared"
 )

@@ -26,8 +25,8 @@ func SourceRefsEqual(left, right []source.SourceRef) bool {
 	return true
 }

-// Less defines the canonical order for NPC interaction occurrences.
-func Less(order shared.SourceRefOrder, left, right dnd.NPCInteraction) bool {
+// Less defines the canonical order for NPC occurrences.
+func Less(order shared.SourceRefOrder, left, right dnd.NPCOccurrence) bool {
 	leftPosition, leftHasEvidence := order.EarliestValid(left.SourceRefs)
 	rightPosition, rightHasEvidence := order.EarliestValid(right.SourceRefs)
 	if leftHasEvidence != rightHasEvidence {
@@ -36,8 +35,8 @@ func Less(order shared.SourceRefOrder, left, right dnd.NPCInteraction) bool {
 	if leftHasEvidence && leftPosition != rightPosition {
 		return leftPosition < rightPosition
 	}
-	leftKey := identity.ComparisonKey(left.Name)
-	rightKey := identity.ComparisonKey(right.Name)
+	leftKey := left.NPCID
+	rightKey := right.NPCID
 	if leftKey != rightKey {
 		return leftKey < rightKey
 	}
@@ -50,7 +49,7 @@ func Less(order shared.SourceRefOrder, left, right dnd.NPCInteraction) bool {
 	return sourceRefsLess(order, left.SourceRefs, right.SourceRefs)
 }

-// ValidSourceRefs reports whether an interaction has non-empty, valid
+// ValidSourceRefs reports whether an occurrence has non-empty, valid
 // current-document evidence.
 func ValidSourceRefs(index source.DocumentIndex, refs []source.SourceRef) bool {
 	if len(refs) == 0 {
@@ -64,13 +63,14 @@ func ValidSourceRefs(index source.DocumentIndex, refs []source.SourceRef) bool {
 	return true
 }

-// ExactIdentity returns a collision-safe key over every durable interaction
+// ExactIdentity returns a collision-safe key over every durable occurrence
 // field. Callers decide whether the record is eligible for duplicate handling.
-func ExactIdentity(interaction dnd.NPCInteraction) string {
+func ExactIdentity(occurrence dnd.NPCOccurrence) string {
 	var key strings.Builder
-	writeKeyString(&key, interaction.Name)
-	writeKeyString(&key, string(interaction.Kind))
-	for _, ref := range interaction.SourceRefs {
+	writeKeyString(&key, occurrence.NPCID)
+	writeKeyString(&key, occurrence.Name)
+	writeKeyString(&key, string(occurrence.Kind))
+	for _, ref := range occurrence.SourceRefs {
 		writeKeyString(&key, ref.SourceID)
 		writeKeyInt(&key, ref.StartUnitID)
 		writeKeyInt(&key, ref.EndUnitID)
--- a/internal/modules/dnd/npcs/registry/registry.go
+++ b/internal/modules/dnd/npcs/registry/registry.go
@@ -32,7 +32,9 @@ type Registry struct {
 	digest           string
 	projectionDigest string
 	promptInput      contracts.LLMInputMaterial
+	identityInput    contracts.LLMInputMaterial
 	lookupByKey      map[string]int
+	lookupByID       map[string]int
 }

 // Resolver selects and memoizes immutable NPC registry views.
@@ -109,7 +111,9 @@ func emptyRegistry() *Registry {
 		canonical:        append([]byte(nil), content...),
 		projectionDigest: projectionDigest,
 		promptInput:      contracts.NewLLMInputMaterial(ReferenceSlot, npccodec.MediaType, content, projectionDigest, ""),
+		identityInput:    contracts.NewLLMInputMaterial(ReferenceSlot, npccodec.MediaType, content, projectionDigest, ""),
 		lookupByKey:      map[string]int{},
+		lookupByID:       map[string]int{},
 	}
 }

@@ -129,8 +133,10 @@ func loadRegistry(referenceContent []byte) (*Registry, error) {

 	list := cloneNPCRegistry(value)
 	lookupByKey := make(map[string]int, len(list.NPCs))
+	lookupByID := make(map[string]int, len(list.NPCs))
 	for index, npc := range list.NPCs {
 		lookupByKey[identity.ComparisonKey(npc.Name)] = index
+		lookupByID[npc.ID] = index
 	}
 	digest := semanticDigest(content)
 	projection, err := nameProjection(list)
@@ -138,6 +144,11 @@ func loadRegistry(referenceContent []byte) (*Registry, error) {
 		return nil, fmt.Errorf("encode NPC name projection: %w", err)
 	}
 	projectionDigest := semanticDigest(projection)
+	identityProjection, err := identityProjection(list)
+	if err != nil {
+		return nil, fmt.Errorf("encode NPC identity projection: %w", err)
+	}
+	identityProjectionDigest := semanticDigest(identityProjection)
 	return &Registry{
 		bound:            true,
 		list:             list,
@@ -146,6 +157,8 @@ func loadRegistry(referenceContent []byte) (*Registry, error) {
 		projectionDigest: projectionDigest,
 		promptInput:      contracts.NewLLMInputMaterial(ReferenceSlot, npccodec.MediaType, projection, projectionDigest, ""),
 		lookupByKey:      lookupByKey,
+		identityInput:    contracts.NewLLMInputMaterial(ReferenceSlot, npccodec.MediaType, identityProjection, identityProjectionDigest, ""),
+		lookupByID:       lookupByID,
 	}, nil
 }

@@ -211,6 +224,15 @@ func (r *Registry) PromptInput() contracts.LLMInputMaterial {
 	return r.promptInput.Clone()
 }

+// IdentityPromptInput returns the ordered ID/name projection for consumers
+// that must bind output records to exact registry identities.
+func (r *Registry) IdentityPromptInput() contracts.LLMInputMaterial {
+	if r == nil {
+		return contracts.LLMInputMaterial{}
+	}
+	return r.identityInput.Clone()
+}
+
 // Lookup returns the canonical NPC for an exact canonical-name match under the
 // NPC identity comparison policy.
 func (r *Registry) Lookup(value string) (dnd.NPC, bool) {
@@ -224,6 +246,18 @@ func (r *Registry) Lookup(value string) (dnd.NPC, bool) {
 	return cloneNPC(r.list.NPCs[index]), true
 }

+// LookupID returns the canonical NPC for an exact durable ID.
+func (r *Registry) LookupID(value string) (dnd.NPC, bool) {
+	if r == nil {
+		return dnd.NPC{}, false
+	}
+	index, ok := r.lookupByID[value]
+	if !ok {
+		return dnd.NPC{}, false
+	}
+	return cloneNPC(r.list.NPCs[index]), true
+}
+
 func semanticDigest(content []byte) string {
 	sum := sha256.Sum256(content)
 	return "sha256:" + hex.EncodeToString(sum[:])
@@ -233,10 +267,19 @@ type projectedNPC struct {
 	Name string `json:"name"`
 }

+type identityProjectedNPC struct {
+	ID   string `json:"id"`
+	Name string `json:"name"`
+}
+
 type projectedNPCRegistry struct {
 	NPCs []projectedNPC `json:"npcs"`
 }

+type identityProjectedNPCRegistry struct {
+	NPCs []identityProjectedNPC `json:"npcs"`
+}
+
 func nameProjection(list dnd.NPCRegistry) ([]byte, error) {
 	projection := projectedNPCRegistry{NPCs: make([]projectedNPC, len(list.NPCs))}
 	for index, npc := range list.NPCs {
@@ -245,6 +288,14 @@ func nameProjection(list dnd.NPCRegistry) ([]byte, error) {
 	return json.Marshal(projection)
 }

+func identityProjection(list dnd.NPCRegistry) ([]byte, error) {
+	projection := identityProjectedNPCRegistry{NPCs: make([]identityProjectedNPC, len(list.NPCs))}
+	for index, npc := range list.NPCs {
+		projection.NPCs[index] = identityProjectedNPC{ID: npc.ID, Name: npc.Name}
+	}
+	return json.Marshal(projection)
+}
+
 func formatIdentityIssues(issues []identity.Issue) string {
 	parts := make([]string, len(issues))
 	for index, issue := range issues {
--- a/internal/modules/dnd/npcs/registry/registry_test.go
+++ b/internal/modules/dnd/npcs/registry/registry_test.go
@@ -19,7 +19,7 @@ func TestResolveUnboundRegistryHasExactEmptyProjection(t *testing.T) {
 		t.Fatalf("Resolve() error = %v", err)
 	}
 	input := registry.PromptInput()
-	if registry.Bound() || registry.Digest() != "" || registry.Count() != 0 || string(input.Content) != emptyPrompt {
+	if registry.Bound() || registry.Digest() != "" || registry.Count() != 0 || string(input.Content) != emptyPrompt || string(registry.IdentityPromptInput().Content) != emptyPrompt {
 		t.Fatalf("registry = %#v input = %#v, want unbound empty registry", registry, input)
 	}
 	if registry.ProjectionDigest() == "" || input.Digest != registry.ProjectionDigest() || input.OriginURI != "" {
@@ -46,6 +46,21 @@ func TestResolveKeepsDurableProvenanceAndProjectsOnlyOrderedNames(t *testing.T)
 	}
 }

+func TestIdentityPromptInputProjectsOrderedIDsAndNames(t *testing.T) {
+	registry := resolveList(t, registryFixture())
+	input := registry.IdentityPromptInput()
+	want := `{"npcs":[{"id":"` + identity.DeriveID("Mira Thorn") + `","name":"Mira Thorn"},{"id":"` + identity.DeriveID("Captain Vale") + `","name":"Captain Vale"}]}`
+	if string(input.Content) != want || input.Digest == registry.ProjectionDigest() {
+		t.Fatalf("identity projection = %#v, want %s", input, want)
+	}
+	if npc, ok := registry.LookupID(identity.DeriveID("Mira Thorn")); !ok || npc.Name != "Mira Thorn" {
+		t.Fatalf("LookupID() = %#v, %t", npc, ok)
+	}
+	if _, ok := registry.LookupID("npc:unknown"); ok {
+		t.Fatal("LookupID() accepted an unknown ID")
+	}
+}
+
 func TestNameProjectionDigestTracksOnlyNamesAndOrder(t *testing.T) {
 	base := registryFixture()
 	evidenceChanged := registryFixture()
--- a/internal/modules/dnd/register/evidence.go
+++ b/internal/modules/dnd/register/evidence.go
@@ -20,7 +20,7 @@ func registerEvidence(registry *pipeline.ArtifactEvidenceRegistry) error {
 			return pipeline.RegisterArtifactEvidence(registry, dnd.ItemEventListKind, itemEventEvidence)
 		}},
 		{name: "npc interactions evidence", register: func() error {
-			return pipeline.RegisterArtifactEvidence(registry, dnd.NPCInteractionListKind, npcInteractionEvidence)
+			return pipeline.RegisterArtifactEvidence(registry, dnd.NPCOccurrenceListKind, npcInteractionEvidence)
 		}},
 		{name: "scene descriptions evidence", register: func() error {
 			return pipeline.RegisterArtifactEvidence(registry, dnd.SceneDescriptionListKind, sceneDescriptionEvidence)
@@ -74,9 +74,9 @@ func itemEventEvidence(value dnd.ItemEventList) []source.SourceRef {
 	return append([]source.SourceRef(nil), refs...)
 }

-func npcInteractionEvidence(value dnd.NPCInteractionList) []source.SourceRef {
+func npcInteractionEvidence(value dnd.NPCOccurrenceList) []source.SourceRef {
 	var refs []source.SourceRef
-	for _, record := range value.Interactions {
+	for _, record := range value.Occurrences {
 		refs = append(refs, record.SourceRefs...)
 	}
 	return append([]source.SourceRef(nil), refs...)
--- a/internal/modules/dnd/register/merge.go
+++ b/internal/modules/dnd/register/merge.go
@@ -112,22 +112,22 @@ func appendItemEventLists(values []dnd.ItemEventList) (dnd.ItemEventList, error)
 	return combined, nil
 }

-func appendNPCInteractionLists(values []dnd.NPCInteractionList) (dnd.NPCInteractionList, error) {
+func appendNPCInteractionLists(values []dnd.NPCOccurrenceList) (dnd.NPCOccurrenceList, error) {
 	count := 0
 	present := false
 	for _, value := range values {
-		if value.Interactions != nil {
+		if value.Occurrences != nil {
 			present = true
 		}
-		count += len(value.Interactions)
+		count += len(value.Occurrences)
 	}
 	if !present {
-		return dnd.NPCInteractionList{}, nil
+		return dnd.NPCOccurrenceList{}, nil
 	}
-	combined := dnd.NPCInteractionList{Interactions: make([]dnd.NPCInteraction, 0, count)}
+	combined := dnd.NPCOccurrenceList{Occurrences: make([]dnd.NPCOccurrence, 0, count)}
 	for _, value := range values {
-		for _, interaction := range value.Interactions {
-			combined.Interactions = append(combined.Interactions, cloneNPCInteraction(interaction))
+		for _, occurrence := range value.Occurrences {
+			combined.Occurrences = append(combined.Occurrences, cloneNPCOccurrence(occurrence))
 		}
 	}
 	return combined, nil
@@ -228,7 +228,7 @@ func cloneNPC(value dnd.NPC) dnd.NPC {
 	return clone
 }

-func cloneNPCInteraction(value dnd.NPCInteraction) dnd.NPCInteraction {
+func cloneNPCOccurrence(value dnd.NPCOccurrence) dnd.NPCOccurrence {
 	clone := value
 	clone.SourceRefs = cloneSourceRefs(value.SourceRefs)
 	return clone
--- a/internal/modules/dnd/register/modules.go
+++ b/internal/modules/dnd/register/modules.go
@@ -79,7 +79,7 @@ func registerModules(registries pipeline.Registries) error {
 			return appendorder.RegisterTyped(registries.Mergers, dnd.ItemEventListKind, appendItemEventLists)
 		}},
 		{name: "npc-interaction-list appendorder merger", register: func() error {
-			return appendorder.RegisterTyped(registries.Mergers, dnd.NPCInteractionListKind, appendNPCInteractionLists)
+			return appendorder.RegisterTyped(registries.Mergers, dnd.NPCOccurrenceListKind, appendNPCInteractionLists)
 		}},
 		{name: "scene-description-list appendorder merger", register: func() error {
 			return appendorder.RegisterTyped(registries.Mergers, dnd.SceneDescriptionListKind, appendSceneDescriptionLists)
@@ -115,7 +115,7 @@ func registerModules(registries pipeline.Registries) error {
 			return noop.RegisterTyped[dnd.ItemEventList](registries.Normalizers, dnd.ItemEventListKind)
 		}},
 		{name: "npc-interaction-list noop normalizer", register: func() error {
-			return noop.RegisterTyped[dnd.NPCInteractionList](registries.Normalizers, dnd.NPCInteractionListKind)
+			return noop.RegisterTyped[dnd.NPCOccurrenceList](registries.Normalizers, dnd.NPCOccurrenceListKind)
 		}},
 		{name: "scene-description-list noop normalizer", register: func() error {
 			return noop.RegisterTyped[dnd.SceneDescriptionList](registries.Normalizers, dnd.SceneDescriptionListKind)
--- a/internal/modules/dnd/register/register_test.go
+++ b/internal/modules/dnd/register/register_test.go
@@ -84,15 +84,15 @@ func TestRegisterAddsDNDFamily(t *testing.T) {
 	assertContainsKeys(t, "chunkers", registries.Chunkers.RegisteredKeys(), []string{"dnd/scenes"})
 	assertContainsKeys(t, "extractors", registries.Extractors.RegisteredKeys(), []string{"dnd/spells", npcextract.Key, combatextract.Key, enemyeventextract.Key, itemeventextract.Key, interactionextract.Key, scenedescriptionextract.Key, locationextract.Key, locationoccurrenceextract.Key})
 	assertContainsKeys(t, "normalizers", registries.Normalizers.RegisteredKeys(), []string{spellnormalize.Key, npcnormalize.Key, combatnormalize.Key, enemyeventnormalize.Key, itemeventnormalize.Key, interactionnormalize.Key, scenedescriptionnormalize.Key, locationnormalize.Key, locationoccurrencenormalize.Key, pipeline.DefaultNormalizeModule})
-	assertContainsArtifactKinds(t, registries.ArtifactCodecs.RegisteredKinds(), []contracts.ArtifactKind{dnd.SpellListKind, dnd.NPCRegistryKind, dnd.CombatTurnListKind, dnd.EnemyEventListKind, dnd.ItemEventListKind, dnd.NPCInteractionListKind, dnd.SceneDescriptionListKind, dnd.LocationListKind, dnd.LocationOccurrenceListKind})
-	assertContainsArtifactKinds(t, registries.ArtifactEvidence.RegisteredKinds(), []contracts.ArtifactKind{dnd.SpellListKind, dnd.NPCRegistryKind, dnd.CombatTurnListKind, dnd.EnemyEventListKind, dnd.ItemEventListKind, dnd.NPCInteractionListKind, dnd.SceneDescriptionListKind, dnd.LocationListKind, dnd.LocationOccurrenceListKind})
-	assertContainsArtifactKinds(t, registries.Mergers.RegisteredArtifactKinds(pipeline.DefaultMergeModule), []contracts.ArtifactKind{dnd.SpellListKind, dnd.NPCRegistryKind, dnd.CombatTurnListKind, dnd.EnemyEventListKind, dnd.ItemEventListKind, dnd.NPCInteractionListKind, dnd.SceneDescriptionListKind, dnd.LocationListKind, dnd.LocationOccurrenceListKind})
-	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(pipeline.DefaultNormalizeModule), []contracts.ArtifactKind{dnd.SpellListKind, dnd.NPCRegistryKind, dnd.CombatTurnListKind, dnd.EnemyEventListKind, dnd.ItemEventListKind, dnd.NPCInteractionListKind, dnd.SceneDescriptionListKind, dnd.LocationListKind, dnd.LocationOccurrenceListKind})
+	assertContainsArtifactKinds(t, registries.ArtifactCodecs.RegisteredKinds(), []contracts.ArtifactKind{dnd.SpellListKind, dnd.NPCRegistryKind, dnd.CombatTurnListKind, dnd.EnemyEventListKind, dnd.ItemEventListKind, dnd.NPCOccurrenceListKind, dnd.SceneDescriptionListKind, dnd.LocationListKind, dnd.LocationOccurrenceListKind})
+	assertContainsArtifactKinds(t, registries.ArtifactEvidence.RegisteredKinds(), []contracts.ArtifactKind{dnd.SpellListKind, dnd.NPCRegistryKind, dnd.CombatTurnListKind, dnd.EnemyEventListKind, dnd.ItemEventListKind, dnd.NPCOccurrenceListKind, dnd.SceneDescriptionListKind, dnd.LocationListKind, dnd.LocationOccurrenceListKind})
+	assertContainsArtifactKinds(t, registries.Mergers.RegisteredArtifactKinds(pipeline.DefaultMergeModule), []contracts.ArtifactKind{dnd.SpellListKind, dnd.NPCRegistryKind, dnd.CombatTurnListKind, dnd.EnemyEventListKind, dnd.ItemEventListKind, dnd.NPCOccurrenceListKind, dnd.SceneDescriptionListKind, dnd.LocationListKind, dnd.LocationOccurrenceListKind})
+	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(pipeline.DefaultNormalizeModule), []contracts.ArtifactKind{dnd.SpellListKind, dnd.NPCRegistryKind, dnd.CombatTurnListKind, dnd.EnemyEventListKind, dnd.ItemEventListKind, dnd.NPCOccurrenceListKind, dnd.SceneDescriptionListKind, dnd.LocationListKind, dnd.LocationOccurrenceListKind})
 	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(npcnormalize.Key), []contracts.ArtifactKind{dnd.NPCRegistryKind})
 	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(combatnormalize.Key), []contracts.ArtifactKind{dnd.CombatTurnListKind})
 	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(enemyeventnormalize.Key), []contracts.ArtifactKind{dnd.EnemyEventListKind})
 	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(itemeventnormalize.Key), []contracts.ArtifactKind{dnd.ItemEventListKind})
-	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(interactionnormalize.Key), []contracts.ArtifactKind{dnd.NPCInteractionListKind})
+	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(interactionnormalize.Key), []contracts.ArtifactKind{dnd.NPCOccurrenceListKind})
 	assertContainsArtifactKinds(t, registries.Normalizers.RegisteredArtifactKinds(scenedescriptionnormalize.Key), []contracts.ArtifactKind{dnd.SceneDescriptionListKind})
 	assertContainsKeys(t, "validators", registries.Validators.RegisteredKeys(), []string{
 		"extract/dnd/locations/shape", "normalize/dnd/locations/identity", "extract/dnd/locations/source_refs", "extract/dnd/locations/source_relatedness",
@@ -302,7 +302,7 @@ func TestRegisterAddsDNDFamily(t *testing.T) {
 		"dnd_combat_turns_llm.v1.json",
 		"dnd_enemy_events_llm.v1.json",
 		"dnd_item_events_llm.v1.json",
-		"dnd_npc_interactions_llm.v1.json",
+		"dnd_npc_occurrences_llm.v1.json",
 		"dnd_scene_descriptions_llm.v1.json",
 		"dnd_locations_llm.v1.json",
 		"dnd_location_occurrences_llm.v1.json",
@@ -353,7 +353,7 @@ func TestRegisterAddsDNDFamily(t *testing.T) {
 	}
 	interactionExtractSpec, extractOK := registries.Extractors.Spec(interactionextract.Key)
 	interactionNormalizeSpec, normalizeOK := registries.Normalizers.Spec(interactionnormalize.Key)
-	if !extractOK || interactionExtractSpec.ArtifactKind != dnd.NPCInteractionListKind || !normalizeOK || interactionNormalizeSpec.ArtifactKind != dnd.NPCInteractionListKind || interactionNormalizeSpec.Stage != pipeline.StageNormalize {
+	if !extractOK || interactionExtractSpec.ArtifactKind != dnd.NPCOccurrenceListKind || !normalizeOK || interactionNormalizeSpec.ArtifactKind != dnd.NPCOccurrenceListKind || interactionNormalizeSpec.Stage != pipeline.StageNormalize {
 		t.Fatalf("NPC interaction specs = %#v / %#v, present = %t / %t", interactionExtractSpec, interactionNormalizeSpec, extractOK, normalizeOK)
 	}
 	locationExtractSpec, locationExtractOK := registries.Extractors.Spec(locationextract.Key)
@@ -419,7 +419,7 @@ func TestEvidenceProjectorsPreserveDirectReferencesWithIndependentStorage(t *tes
 			return itemEventEvidence(dnd.ItemEventList{Events: []dnd.ItemEvent{{SourceRefs: []source.SourceRef{first, second}}}})
 		}, want: []source.SourceRef{first, second}},
 		{name: "npc interactions", project: func() []source.SourceRef {
-			return npcInteractionEvidence(dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{SourceRefs: []source.SourceRef{first, second}}}})
+			return npcInteractionEvidence(dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{SourceRefs: []source.SourceRef{first, second}}}})
 		}, want: []source.SourceRef{first, second}},
 		{name: "scene descriptions", project: func() []source.SourceRef {
 			return sceneDescriptionEvidence(dnd.SceneDescriptionList{Scenes: []dnd.SceneDescription{{SourceRef: first}, {SourceRef: second}}})
@@ -561,26 +561,26 @@ func TestAppendSpellListsPreservesOrderPresenceAndOwnership(t *testing.T) {

 func TestAppendNPCInteractionListsPreservesOrderPresenceAndOwnership(t *testing.T) {
 	refs := []source.SourceRef{{SourceID: "session", StartUnitID: 10, EndUnitID: 10}}
-	input := []dnd.NPCInteractionList{
+	input := []dnd.NPCOccurrenceList{
 		{},
-		{Interactions: []dnd.NPCInteraction{}},
-		{Interactions: []dnd.NPCInteraction{{Name: "Aria", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: refs}}},
-		{Interactions: []dnd.NPCInteraction{{Name: "Borin", Kind: dnd.NPCInteractionKindMentioned, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 20, EndUnitID: 20}}}}},
+		{Occurrences: []dnd.NPCOccurrence{}},
+		{Occurrences: []dnd.NPCOccurrence{{Name: "Aria", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: refs}}},
+		{Occurrences: []dnd.NPCOccurrence{{Name: "Borin", Kind: dnd.NPCOccurrenceKindMentioned, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 20, EndUnitID: 20}}}}},
 	}
 	got, err := appendNPCInteractionLists(input)
 	if err != nil {
 		t.Fatalf("appendNPCInteractionLists() error = %v", err)
 	}
-	if got.Interactions == nil || !reflect.DeepEqual([]string{got.Interactions[0].Name, got.Interactions[1].Name}, []string{"Aria", "Borin"}) {
+	if got.Occurrences == nil || !reflect.DeepEqual([]string{got.Occurrences[0].Name, got.Occurrences[1].Name}, []string{"Aria", "Borin"}) {
 		t.Fatalf("combined interactions = %#v", got)
 	}
-	got.Interactions[0].SourceRefs[0].StartUnitID = 999
-	if input[2].Interactions[0].SourceRefs[0].StartUnitID == 999 {
+	got.Occurrences[0].SourceRefs[0].StartUnitID = 999
+	if input[2].Occurrences[0].SourceRefs[0].StartUnitID == 999 {
 		t.Fatal("merged interactions share source reference storage")
 	}
-	for _, values := range [][]dnd.NPCInteractionList{nil, []dnd.NPCInteractionList{{}, {}}} {
+	for _, values := range [][]dnd.NPCOccurrenceList{nil, []dnd.NPCOccurrenceList{{}, {}}} {
 		result, err := appendNPCInteractionLists(values)
-		if err != nil || result.Interactions != nil {
+		if err != nil || result.Occurrences != nil {
 			t.Fatalf("nil-only merge = %#v, %v; want nil interactions", result, err)
 		}
 	}
@@ -711,8 +711,8 @@ func TestAppendListsPreserveNestedSourceReferencePresence(t *testing.T) {
 		t.Fatalf("appendEnemyEventLists() = %#v, %v; want present-empty source refs", enemyEvents, err)
 	}

-	interactions, err := appendNPCInteractionLists([]dnd.NPCInteractionList{{Interactions: []dnd.NPCInteraction{{SourceRefs: []source.SourceRef{}}}}})
-	if err != nil || interactions.Interactions[0].SourceRefs == nil {
+	interactions, err := appendNPCInteractionLists([]dnd.NPCOccurrenceList{{Occurrences: []dnd.NPCOccurrence{{SourceRefs: []source.SourceRef{}}}}})
+	if err != nil || interactions.Occurrences[0].SourceRefs == nil {
 		t.Fatalf("appendNPCInteractionLists() = %#v, %v; want present-empty source refs", interactions, err)
 	}

--- a/internal/modules/dnd/register/validators.go
+++ b/internal/modules/dnd/register/validators.go
@@ -118,10 +118,10 @@ func registerValidators(registries pipeline.Registries) error {
 			return alwaysreject.RegisterTyped[dnd.ItemEventList](registries.Validators, dnd.ItemEventListKind)
 		}},
 		{name: "npc-interaction-list always accept validator", register: func() error {
-			return alwaysaccept.RegisterTyped[dnd.NPCInteractionList](registries.Validators, dnd.NPCInteractionListKind)
+			return alwaysaccept.RegisterTyped[dnd.NPCOccurrenceList](registries.Validators, dnd.NPCOccurrenceListKind)
 		}},
 		{name: "npc-interaction-list always reject validator", register: func() error {
-			return alwaysreject.RegisterTyped[dnd.NPCInteractionList](registries.Validators, dnd.NPCInteractionListKind)
+			return alwaysreject.RegisterTyped[dnd.NPCOccurrenceList](registries.Validators, dnd.NPCOccurrenceListKind)
 		}},
 		{name: "scene-description-list always accept validator", register: func() error {
 			return alwaysaccept.RegisterTyped[dnd.SceneDescriptionList](registries.Validators, dnd.SceneDescriptionListKind)
--- a/internal/modules/dnd/types.go
+++ b/internal/modules/dnd/types.go
@@ -12,7 +12,7 @@ const NPCRegistryKind contracts.ArtifactKind = "dnd/npc-registry"

 const CombatTurnListKind contracts.ArtifactKind = "dnd/combat-turn-list"

-const NPCInteractionListKind contracts.ArtifactKind = "dnd/npc-interaction-list"
+const NPCOccurrenceListKind contracts.ArtifactKind = "dnd/npc-occurrence-list"

 const SceneDescriptionListKind contracts.ArtifactKind = "dnd/scene-description-list"

@@ -64,24 +64,25 @@ type CombatTurn struct {
 	SourceRefs []source.SourceRef `json:"source_refs"`
 }

-type NPCInteractionKind string
+type NPCOccurrenceKind string

 const (
-	NPCInteractionKindMentioned         NPCInteractionKind = "mentioned"
-	NPCInteractionKindNoncombatPresence NPCInteractionKind = "noncombat_presence"
-	NPCInteractionKindDialogue          NPCInteractionKind = "dialogue"
-	NPCInteractionKindCombatAlly        NPCInteractionKind = "combat_ally"
-	NPCInteractionKindCombatOpponent    NPCInteractionKind = "combat_opponent"
-	NPCInteractionKindOther             NPCInteractionKind = "other"
+	NPCOccurrenceKindMentioned         NPCOccurrenceKind = "mentioned"
+	NPCOccurrenceKindNoncombatPresence NPCOccurrenceKind = "noncombat_presence"
+	NPCOccurrenceKindDialogue          NPCOccurrenceKind = "dialogue"
+	NPCOccurrenceKindCombatAlly        NPCOccurrenceKind = "combat_ally"
+	NPCOccurrenceKindCombatOpponent    NPCOccurrenceKind = "combat_opponent"
+	NPCOccurrenceKindOther             NPCOccurrenceKind = "other"
 )

-type NPCInteractionList struct {
-	Interactions []NPCInteraction `json:"interactions"`
+type NPCOccurrenceList struct {
+	Occurrences []NPCOccurrence `json:"occurrences"`
 }

-type NPCInteraction struct {
+type NPCOccurrence struct {
+	NPCID      string             `json:"npc_id"`
 	Name       string             `json:"name"`
-	Kind       NPCInteractionKind `json:"kind"`
+	Kind       NPCOccurrenceKind  `json:"kind"`
 	SourceRefs []source.SourceRef `json:"source_refs"`
 }

--- a/internal/modules/dnd/validate/npcinteractions/invariants/validator.go
+++ b/internal/modules/dnd/validate/npcinteractions/invariants/validator.go
@@ -29,7 +29,7 @@ type Validator struct {
 	npcResolver *npcregistry.Resolver
 }

-var _ contracts.TypedValidator[dnd.NPCInteractionList] = (*Validator)(nil)
+var _ contracts.TypedValidator[dnd.NPCOccurrenceList] = (*Validator)(nil)
 var _ contracts.ManifestMetadataProvider = (*Validator)(nil)
 var _ pipeline.CheckpointFingerprintProvider = (*Validator)(nil)

@@ -72,11 +72,11 @@ func (v *Validator) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
 	}
 	return []pipeline.CheckpointFingerprint{
 		{Name: "policy", Value: policy},
-		{Name: "npc_registry", Value: v.npcResolver.Seeded().ProjectionDigest()},
+		{Name: "npc_registry", Value: v.npcResolver.Seeded().IdentityPromptInput().Digest},
 	}
 }

-func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCInteractionList]) (contracts.ValidationResult, error) {
+func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCOccurrenceList]) (contracts.ValidationResult, error) {
 	if interactionshape.Validate(req.Value) != nil {
 		return contracts.ValidationResult{Approved: true}, nil
 	}
@@ -105,25 +105,28 @@ func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationReq
 	}, nil
 }

-func allSourceRefsValid(index source.DocumentIndex, value dnd.NPCInteractionList) bool {
-	for _, interaction := range value.Interactions {
-		if !interactionmodel.ValidSourceRefs(index, interaction.SourceRefs) {
+func allSourceRefsValid(index source.DocumentIndex, value dnd.NPCOccurrenceList) bool {
+	for _, occurrence := range value.Occurrences {
+		if !interactionmodel.ValidSourceRefs(index, occurrence.SourceRefs) {
 			return false
 		}
 	}
 	return true
 }

-func issuesFor(order shared.SourceRefOrder, value dnd.NPCInteractionList, npcRegistry *npcregistry.Registry) []string {
+func issuesFor(order shared.SourceRefOrder, value dnd.NPCOccurrenceList, npcRegistry *npcregistry.Registry) []string {
 	issues := make([]string, 0)
-	for index, interaction := range value.Interactions {
-		prefix := fmt.Sprintf("interactions[%d]", index)
-		if canonical, ok := npcRegistry.Lookup(interaction.Name); ok && interaction.Name != canonical.Name {
-			issues = append(issues, prefix+".name is not the canonical NPC display name: "+diagnostics.Quote(interaction.Name))
+	for index, occurrence := range value.Occurrences {
+		prefix := fmt.Sprintf("occurrences[%d]", index)
+		canonical, ok := npcRegistry.LookupID(occurrence.NPCID)
+		if !ok {
+			issues = append(issues, prefix+".npc_id is not in the NPC registry: "+diagnostics.Quote(occurrence.NPCID))
+		} else if occurrence.Name != canonical.Name {
+			issues = append(issues, prefix+".name does not match npc_id: "+diagnostics.Quote(occurrence.Name))
 		}
-		for refIndex := 1; refIndex < len(interaction.SourceRefs); refIndex++ {
-			previous := interaction.SourceRefs[refIndex-1]
-			current := interaction.SourceRefs[refIndex]
+		for refIndex := 1; refIndex < len(occurrence.SourceRefs); refIndex++ {
+			previous := occurrence.SourceRefs[refIndex-1]
+			current := occurrence.SourceRefs[refIndex]
 			if order.Less(current, previous) {
 				issues = append(issues, fmt.Sprintf("%s.source_refs are not in canonical order at index %d", prefix, refIndex))
 			} else if current == previous {
@@ -132,16 +135,16 @@ func issuesFor(order shared.SourceRefOrder, value dnd.NPCInteractionList, npcReg
 		}
 	}

-	if !sort.SliceIsSorted(value.Interactions, func(left, right int) bool {
-		return interactionmodel.Less(order, value.Interactions[left], value.Interactions[right])
+	if !sort.SliceIsSorted(value.Occurrences, func(left, right int) bool {
+		return interactionmodel.Less(order, value.Occurrences[left], value.Occurrences[right])
 	}) {
-		issues = append(issues, "interactions are not in canonical order")
+		issues = append(issues, "occurrences are not in canonical order")
 	}
 	seen := make(map[string]int)
-	for index, interaction := range value.Interactions {
-		key := interactionmodel.ExactIdentity(interaction)
+	for index, occurrence := range value.Occurrences {
+		key := interactionmodel.ExactIdentity(occurrence)
 		if previous, ok := seen[key]; ok {
-			issues = append(issues, fmt.Sprintf("interactions[%d] duplicates interaction %d", index, previous))
+			issues = append(issues, fmt.Sprintf("occurrences[%d] duplicates occurrence %d", index, previous))
 			continue
 		}
 		seen[key] = index
@@ -154,7 +157,7 @@ func Spec() pipeline.ValidatorSpec {
 }

 func Register(registry *pipeline.ValidatorRegistry) error {
-	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCInteractionListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCInteractionList], error) {
+	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCOccurrenceListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCOccurrenceList], error) {
 		options, err := DecodeOptions(request.Options)
 		if err != nil {
 			return nil, err
--- a/internal/modules/dnd/validate/npcinteractions/invariants/validator_test.go
+++ b/internal/modules/dnd/validate/npcinteractions/invariants/validator_test.go
@@ -28,26 +28,26 @@ func TestValidatorRejectsOwnedCanonicalNameReferenceOrderListOrderAndDuplicates(
 	references := registryReferences(t, "Aria", "Borin")
 	for _, test := range []struct {
 		name   string
-		mutate func(*dnd.NPCInteractionList)
+		mutate func(*dnd.NPCOccurrenceList)
 		want   string
 	}{
-		{"canonical name", func(value *dnd.NPCInteractionList) { value.Interactions[0].Name = " aria " }, "canonical NPC display name"},
-		{"reference order", func(value *dnd.NPCInteractionList) {
-			value.Interactions[0].SourceRefs = []source.SourceRef{{SourceID: "session", StartUnitID: 20, EndUnitID: 20}, {SourceID: "session", StartUnitID: 10, EndUnitID: 10}}
+		{"mismatched name", func(value *dnd.NPCOccurrenceList) { value.Occurrences[0].Name = " aria " }, "does not match npc_id"},
+		{"reference order", func(value *dnd.NPCOccurrenceList) {
+			value.Occurrences[0].SourceRefs = []source.SourceRef{{SourceID: "session", StartUnitID: 20, EndUnitID: 20}, {SourceID: "session", StartUnitID: 10, EndUnitID: 10}}
 		}, "not in canonical order"},
-		{"duplicate reference", func(value *dnd.NPCInteractionList) {
-			value.Interactions[0].SourceRefs = append(value.Interactions[0].SourceRefs, value.Interactions[0].SourceRefs[0])
+		{"duplicate reference", func(value *dnd.NPCOccurrenceList) {
+			value.Occurrences[0].SourceRefs = append(value.Occurrences[0].SourceRefs, value.Occurrences[0].SourceRefs[0])
 		}, "duplicates the previous reference"},
-		{"list order", func(value *dnd.NPCInteractionList) {
-			value.Interactions[0], value.Interactions[1] = value.Interactions[1], value.Interactions[0]
-		}, "interactions are not in canonical order"},
-		{"name tie breaker", func(value *dnd.NPCInteractionList) {
-			value.Interactions[0] = dnd.NPCInteraction{Name: "Borin", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 10, EndUnitID: 10}}}
-			value.Interactions[1] = dnd.NPCInteraction{Name: "Aria", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 10, EndUnitID: 10}}}
-		}, "interactions are not in canonical order"},
-		{"duplicate record", func(value *dnd.NPCInteractionList) {
-			value.Interactions = append(value.Interactions, value.Interactions[0])
-		}, "duplicates interaction"},
+		{"list order", func(value *dnd.NPCOccurrenceList) {
+			value.Occurrences[0], value.Occurrences[1] = value.Occurrences[1], value.Occurrences[0]
+		}, "occurrences are not in canonical order"},
+		{"NPC ID tie breaker", func(value *dnd.NPCOccurrenceList) {
+			value.Occurrences[0] = dnd.NPCOccurrence{NPCID: identity.DeriveID("Aria"), Name: "Aria", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 10, EndUnitID: 10}}}
+			value.Occurrences[1] = dnd.NPCOccurrence{NPCID: identity.DeriveID("Borin"), Name: "Borin", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 10, EndUnitID: 10}}}
+		}, "occurrences are not in canonical order"},
+		{"duplicate record", func(value *dnd.NPCOccurrenceList) {
+			value.Occurrences = append(value.Occurrences, value.Occurrences[0])
+		}, "duplicates occurrence"},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			value := normalizedList()
@@ -62,9 +62,9 @@ func TestValidatorRejectsOwnedCanonicalNameReferenceOrderListOrderAndDuplicates(

 func TestValidatorAcceptsValidEvidenceBeforeInvalidEvidence(t *testing.T) {
 	references := registryReferences(t, "Aria", "Borin")
-	value := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{
-		{Name: "Borin", Kind: dnd.NPCInteractionKindMentioned, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 20, EndUnitID: 20}}},
-		{Name: "Aria", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 99, EndUnitID: 99}}},
+	value := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{
+		{NPCID: "npc:test", Name: "Borin", Kind: dnd.NPCOccurrenceKindMentioned, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 20, EndUnitID: 20}}},
+		{NPCID: "npc:test", Name: "Aria", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 99, EndUnitID: 99}}},
 	}}
 	result, err := newValidator(t, references).Validate(context.Background(), request(references, value))
 	if err != nil || !result.Approved {
@@ -74,9 +74,9 @@ func TestValidatorAcceptsValidEvidenceBeforeInvalidEvidence(t *testing.T) {

 func TestValidatorDefersShapeAndSourceReferenceFailuresAndRequiresRegistry(t *testing.T) {
 	references := registryReferences(t, "Aria", "Borin")
-	for _, value := range []dnd.NPCInteractionList{
-		{Interactions: []dnd.NPCInteraction{{Name: "Aria"}}},
-		{Interactions: []dnd.NPCInteraction{{Name: "Aria", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 99, EndUnitID: 99}}}}},
+	for _, value := range []dnd.NPCOccurrenceList{
+		{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Aria"}}},
+		{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Aria", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 99, EndUnitID: 99}}}}},
 	} {
 		result, err := newValidator(t, references).Validate(context.Background(), request(references, value))
 		if err != nil || !result.Approved {
@@ -126,26 +126,26 @@ func newValidator(t *testing.T, references ...contracts.ReferenceSet) *Validator
 	return validator
 }

-func request(references contracts.ReferenceSet, value dnd.NPCInteractionList) contracts.TypedValidationRequest[dnd.NPCInteractionList] {
-	return contracts.TypedValidationRequest[dnd.NPCInteractionList]{Source: document(), References: references, Value: value}
+func request(references contracts.ReferenceSet, value dnd.NPCOccurrenceList) contracts.TypedValidationRequest[dnd.NPCOccurrenceList] {
+	return contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{Source: document(), References: references, Value: value}
 }

 func document() *source.SourceDocument {
 	return &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 10}, {ID: 20}}}
 }

-func normalizedList() dnd.NPCInteractionList {
-	return dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{
-		{Name: "Aria", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 10, EndUnitID: 10}}},
-		{Name: "Borin", Kind: dnd.NPCInteractionKindMentioned, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 20, EndUnitID: 20}}},
+func normalizedList() dnd.NPCOccurrenceList {
+	return dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{
+		{NPCID: identity.DeriveID("Aria"), Name: "Aria", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 10, EndUnitID: 10}}},
+		{NPCID: identity.DeriveID("Borin"), Name: "Borin", Kind: dnd.NPCOccurrenceKindMentioned, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 20, EndUnitID: 20}}},
 	}}
 }

-func cloneList(value dnd.NPCInteractionList) dnd.NPCInteractionList {
-	copyValue := dnd.NPCInteractionList{Interactions: make([]dnd.NPCInteraction, len(value.Interactions))}
-	for index, interaction := range value.Interactions {
-		copyValue.Interactions[index] = interaction
-		copyValue.Interactions[index].SourceRefs = append([]source.SourceRef(nil), interaction.SourceRefs...)
+func cloneList(value dnd.NPCOccurrenceList) dnd.NPCOccurrenceList {
+	copyValue := dnd.NPCOccurrenceList{Occurrences: make([]dnd.NPCOccurrence, len(value.Occurrences))}
+	for index, interaction := range value.Occurrences {
+		copyValue.Occurrences[index] = interaction
+		copyValue.Occurrences[index].SourceRefs = append([]source.SourceRef(nil), interaction.SourceRefs...)
 	}
 	return copyValue
 }
--- a/internal/modules/dnd/validate/npcinteractions/registry/validator.go
+++ b/internal/modules/dnd/validate/npcinteractions/registry/validator.go
@@ -25,7 +25,7 @@ type Validator struct {
 	npcResolver *npcregistry.Resolver
 }

-var _ contracts.TypedValidator[dnd.NPCInteractionList] = (*Validator)(nil)
+var _ contracts.TypedValidator[dnd.NPCOccurrenceList] = (*Validator)(nil)
 var _ contracts.ManifestMetadataProvider = (*Validator)(nil)
 var _ pipeline.CheckpointFingerprintProvider = (*Validator)(nil)

@@ -68,11 +68,11 @@ func (v *Validator) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
 	}
 	return []pipeline.CheckpointFingerprint{
 		{Name: "policy", Value: policy},
-		{Name: "npc_registry", Value: v.npcResolver.Seeded().ProjectionDigest()},
+		{Name: "npc_registry", Value: v.npcResolver.Seeded().IdentityPromptInput().Digest},
 	}
 }

-func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCInteractionList]) (contracts.ValidationResult, error) {
+func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCOccurrenceList]) (contracts.ValidationResult, error) {
 	if interactionshape.Validate(req.Value) != nil {
 		return contracts.ValidationResult{Approved: true}, nil
 	}
@@ -87,9 +87,14 @@ func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationReq
 		return rejection([]string{"NPC registry reference is required"}), nil
 	}
 	issues := make([]string, 0)
-	for index, interaction := range req.Value.Interactions {
-		if _, ok := npcRegistry.Lookup(interaction.Name); !ok {
-			issues = append(issues, fmt.Sprintf("interactions[%d].name is not in the NPC registry: %s", index, diagnostics.Quote(interaction.Name)))
+	for index, occurrence := range req.Value.Occurrences {
+		canonical, ok := npcRegistry.LookupID(occurrence.NPCID)
+		if !ok {
+			issues = append(issues, fmt.Sprintf("occurrences[%d].npc_id is not in the NPC registry: %s", index, diagnostics.Quote(occurrence.NPCID)))
+			continue
+		}
+		if occurrence.Name != canonical.Name {
+			issues = append(issues, fmt.Sprintf("occurrences[%d].name does not match npc_id: %s", index, diagnostics.Quote(occurrence.Name)))
 		}
 	}
 	if len(issues) == 0 {
@@ -111,7 +116,7 @@ func Spec() pipeline.ValidatorSpec {
 }

 func Register(registry *pipeline.ValidatorRegistry) error {
-	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCInteractionListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCInteractionList], error) {
+	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCOccurrenceListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCOccurrenceList], error) {
 		options, err := DecodeOptions(request.Options)
 		if err != nil {
 			return nil, err
--- a/internal/modules/dnd/validate/npcinteractions/registry/validator_test.go
+++ b/internal/modules/dnd/validate/npcinteractions/registry/validator_test.go
@@ -16,19 +16,25 @@ import (
 	npcregistry "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcs/registry"
 )

-func TestValidatorRecognizesRegistryNamesAndRejectsUnknownNames(t *testing.T) {
+func TestValidatorRecognizesExactRegistryPairsAndRejectsUnknownIDs(t *testing.T) {
 	references := registryReferences(t, "Mira Thorn")
 	validator := newValidator(t, references)
-	value := validList("  mira thorn  ")
+	value := validList("Mira Thorn")
 	result, err := validator.Validate(context.Background(), request(references, value))
 	if err != nil || !result.Approved {
 		t.Fatalf("recognized result = %#v, %v", result, err)
 	}
-	value.Interactions[0].Name = "Unknown NPC"
+	value.Occurrences[0].NPCID = "npc:unknown"
 	result, err = validator.Validate(context.Background(), request(references, value))
-	if err != nil || result.Approved || result.ReasonCode != ReasonCode || !strings.Contains(result.Message, "interactions[0].name") {
+	if err != nil || result.Approved || result.ReasonCode != ReasonCode || !strings.Contains(result.Message, "occurrences[0].npc_id") {
 		t.Fatalf("unknown result = %#v, %v", result, err)
 	}
+	value = validList("Mira Thorn")
+	value.Occurrences[0].Name = "Hooded Guard"
+	result, err = validator.Validate(context.Background(), request(references, value))
+	if err != nil || result.Approved || result.ReasonCode != ReasonCode || !strings.Contains(result.Message, "does not match npc_id") {
+		t.Fatalf("mismatched result = %#v, %v", result, err)
+	}
 }

 func TestValidatorRequiresRegistryAndResolvesGeneratedReferenceAtOperationTime(t *testing.T) {
@@ -45,7 +51,7 @@ func TestValidatorRequiresRegistryAndResolvesGeneratedReferenceAtOperationTime(t
 	}

 	empty := registryReferences(t)
-	result, err = newValidator(t, empty).Validate(context.Background(), request(empty, dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{}}))
+	result, err = newValidator(t, empty).Validate(context.Background(), request(empty, dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{}}))
 	if err != nil || !result.Approved {
 		t.Fatalf("empty registry result = %#v, %v", result, err)
 	}
@@ -78,7 +84,7 @@ func TestValidatorRejectsMalformedRegistryWithoutContentAndKeepsMetadataSafe(t *
 func TestValidatorDefersShapeAndDoesNotMutateOrMisregister(t *testing.T) {
 	references := registryReferences(t, "Mira Thorn")
 	validator := newValidator(t, references)
-	malformed := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{Name: "Mira Thorn"}}}
+	malformed := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Mira Thorn"}}}
 	result, err := validator.Validate(context.Background(), request(references, malformed))
 	if err != nil || !result.Approved {
 		t.Fatalf("shape deferral = %#v, %v", result, err)
@@ -107,13 +113,13 @@ func newValidator(t *testing.T, references ...contracts.ReferenceSet) *Validator
 	return validator
 }

-func request(references contracts.ReferenceSet, value dnd.NPCInteractionList) contracts.TypedValidationRequest[dnd.NPCInteractionList] {
-	return contracts.TypedValidationRequest[dnd.NPCInteractionList]{References: references, Value: value}
+func request(references contracts.ReferenceSet, value dnd.NPCOccurrenceList) contracts.TypedValidationRequest[dnd.NPCOccurrenceList] {
+	return contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{References: references, Value: value}
 }

-func validList(name string) dnd.NPCInteractionList {
-	return dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{
-		Name: name, Kind: dnd.NPCInteractionKindDialogue,
+func validList(name string) dnd.NPCOccurrenceList {
+	return dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{
+		NPCID: identity.DeriveID(name), Name: name, Kind: dnd.NPCOccurrenceKindDialogue,
 		SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 1}},
 	}}}
 }
--- a/internal/modules/dnd/validate/npcinteractions/shape/validator.go
+++ b/internal/modules/dnd/validate/npcinteractions/shape/validator.go
@@ -21,7 +21,7 @@ const (
 type Options struct{}
 type Validator struct{}

-var _ contracts.TypedValidator[dnd.NPCInteractionList] = (*Validator)(nil)
+var _ contracts.TypedValidator[dnd.NPCOccurrenceList] = (*Validator)(nil)
 var _ pipeline.CheckpointFingerprintProvider = (*Validator)(nil)

 func New(Options) *Validator      { return &Validator{} }
@@ -33,14 +33,14 @@ func (v *Validator) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
 	return []pipeline.CheckpointFingerprint{{Name: "policy", Value: policy}}
 }

-func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCInteractionList]) (contracts.ValidationResult, error) {
+func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCOccurrenceList]) (contracts.ValidationResult, error) {
 	if err := Validate(req.Value); err != nil {
 		return contracts.ValidationResult{Approved: false, ReasonCode: ReasonCode, Message: err.Error()}, nil
 	}
 	return contracts.ValidationResult{Approved: true}, nil
 }

-func Validate(value dnd.NPCInteractionList) error {
+func Validate(value dnd.NPCOccurrenceList) error {
 	issues := issuesFor(value)
 	if len(issues) == 0 {
 		return nil
@@ -48,34 +48,37 @@ func Validate(value dnd.NPCInteractionList) error {
 	return fmt.Errorf("%s", diagnostics.Aggregate("invalid NPC interaction shape", issues))
 }

-func issuesFor(value dnd.NPCInteractionList) []string {
-	if value.Interactions == nil {
-		return []string{"interactions must be present"}
+func issuesFor(value dnd.NPCOccurrenceList) []string {
+	if value.Occurrences == nil {
+		return []string{"occurrences must be present"}
 	}
 	issues := make([]string, 0)
-	for index, interaction := range value.Interactions {
-		prefix := fmt.Sprintf("interactions[%d]", index)
-		if strings.TrimSpace(interaction.Name) == "" {
-			issues = append(issues, prefix+".name must not be empty: "+diagnostics.Quote(interaction.Name))
+	for index, occurrence := range value.Occurrences {
+		prefix := fmt.Sprintf("occurrences[%d]", index)
+		if strings.TrimSpace(occurrence.NPCID) == "" {
+			issues = append(issues, prefix+".npc_id must not be empty: "+diagnostics.Quote(occurrence.NPCID))
 		}
-		if !validKind(interaction.Kind) {
-			issues = append(issues, prefix+".kind is unsupported: "+diagnostics.Quote(string(interaction.Kind)))
+		if strings.TrimSpace(occurrence.Name) == "" {
+			issues = append(issues, prefix+".name must not be empty: "+diagnostics.Quote(occurrence.Name))
 		}
-		if len(interaction.SourceRefs) == 0 {
+		if !validKind(occurrence.Kind) {
+			issues = append(issues, prefix+".kind is unsupported: "+diagnostics.Quote(string(occurrence.Kind)))
+		}
+		if len(occurrence.SourceRefs) == 0 {
 			issues = append(issues, prefix+".source_refs must contain at least one reference")
 		}
 	}
 	return issues
 }

-func validKind(value dnd.NPCInteractionKind) bool {
+func validKind(value dnd.NPCOccurrenceKind) bool {
 	switch value {
-	case dnd.NPCInteractionKindMentioned,
-		dnd.NPCInteractionKindNoncombatPresence,
-		dnd.NPCInteractionKindDialogue,
-		dnd.NPCInteractionKindCombatAlly,
-		dnd.NPCInteractionKindCombatOpponent,
-		dnd.NPCInteractionKindOther:
+	case dnd.NPCOccurrenceKindMentioned,
+		dnd.NPCOccurrenceKindNoncombatPresence,
+		dnd.NPCOccurrenceKindDialogue,
+		dnd.NPCOccurrenceKindCombatAlly,
+		dnd.NPCOccurrenceKindCombatOpponent,
+		dnd.NPCOccurrenceKindOther:
 		return true
 	default:
 		return false
@@ -87,7 +90,7 @@ func Spec() pipeline.ValidatorSpec {
 }

 func Register(registry *pipeline.ValidatorRegistry) error {
-	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCInteractionListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCInteractionList], error) {
+	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCOccurrenceListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCOccurrenceList], error) {
 		options, err := DecodeOptions(request.Options)
 		if err != nil {
 			return nil, err
--- a/internal/modules/dnd/validate/npcinteractions/shape/validator_test.go
+++ b/internal/modules/dnd/validate/npcinteractions/shape/validator_test.go
@@ -15,22 +15,22 @@ import (

 func TestValidatorOwnsRequiredNameKindAndEvidence(t *testing.T) {
 	valid := validList()
-	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{Value: valid})
+	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{Value: valid})
 	if err != nil || !result.Approved {
 		t.Fatalf("Validate() = %#v, %v", result, err)
 	}
 	for _, test := range []struct {
 		name  string
-		value dnd.NPCInteractionList
+		value dnd.NPCOccurrenceList
 		want  string
 	}{
-		{"missing interactions", dnd.NPCInteractionList{}, "interactions must be present"},
-		{"blank name", dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{Name: " ", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: valid.Interactions[0].SourceRefs}}}, "name must not be empty"},
-		{"unsupported kind", dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{Name: "Mira Thorn", Kind: "unsupported", SourceRefs: valid.Interactions[0].SourceRefs}}}, "kind is unsupported"},
-		{"missing evidence", dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{Name: "Mira Thorn", Kind: dnd.NPCInteractionKindDialogue}}}, "source_refs must contain"},
+		{"missing occurrences", dnd.NPCOccurrenceList{}, "occurrences must be present"},
+		{"blank name", dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: " ", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: valid.Occurrences[0].SourceRefs}}}, "name must not be empty"},
+		{"unsupported kind", dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Mira Thorn", Kind: "unsupported", SourceRefs: valid.Occurrences[0].SourceRefs}}}, "kind is unsupported"},
+		{"missing evidence", dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Mira Thorn", Kind: dnd.NPCOccurrenceKindDialogue}}}, "source_refs must contain"},
 	} {
 		t.Run(test.name, func(t *testing.T) {
-			result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{Value: test.value})
+			result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{Value: test.value})
 			if err != nil || result.Approved || result.ReasonCode != ReasonCode || !strings.Contains(result.Message, test.want) {
 				t.Fatalf("Validate() = %#v, %v; want %q", result, err, test.want)
 			}
@@ -39,15 +39,15 @@ func TestValidatorOwnsRequiredNameKindAndEvidence(t *testing.T) {
 }

 func TestValidatorBoundsDiagnosticsPreservesValueAndRegistersTypedContract(t *testing.T) {
-	value := dnd.NPCInteractionList{Interactions: make([]dnd.NPCInteraction, 24)}
-	for index := range value.Interactions {
-		value.Interactions[index] = dnd.NPCInteraction{Name: strings.Repeat("火", 220) + "\n", Kind: "unsupported"}
+	value := dnd.NPCOccurrenceList{Occurrences: make([]dnd.NPCOccurrence, 24)}
+	for index := range value.Occurrences {
+		value.Occurrences[index] = dnd.NPCOccurrence{NPCID: "npc:test", Name: strings.Repeat("火", 220) + "\n", Kind: "unsupported"}
 	}
-	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{Value: value})
+	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{Value: value})
 	if err != nil || result.Approved || len([]byte(result.Message)) > 4096 || !utf8.ValidString(result.Message) || !strings.Contains(result.Message, "additional issue(s) omitted") {
 		t.Fatalf("Validate() = %#v, %v", result, err)
 	}
-	if value.Interactions[0].Name != strings.Repeat("火", 220)+"\n" {
+	if value.Occurrences[0].Name != strings.Repeat("火", 220)+"\n" {
 		t.Fatal("Validate() mutated input")
 	}
 	if got := New(Options{}).CheckpointFingerprints(); !reflect.DeepEqual(got, []pipeline.CheckpointFingerprint{{Name: "policy", Value: policy}}) {
@@ -62,9 +62,9 @@ func TestValidatorBoundsDiagnosticsPreservesValueAndRegistersTypedContract(t *te
 	}
 }

-func validList() dnd.NPCInteractionList {
-	return dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{
-		Name: "Mira Thorn", Kind: dnd.NPCInteractionKindDialogue,
+func validList() dnd.NPCOccurrenceList {
+	return dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{
+		NPCID: "npc:test", Name: "Mira Thorn", Kind: dnd.NPCOccurrenceKindDialogue,
 		SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 1}},
 	}}}
 }
--- a/internal/modules/dnd/validate/npcinteractions/source_refs/validator.go
+++ b/internal/modules/dnd/validate/npcinteractions/source_refs/validator.go
@@ -22,7 +22,7 @@ const (
 type Options struct{}
 type Validator struct{}

-var _ contracts.TypedValidator[dnd.NPCInteractionList] = (*Validator)(nil)
+var _ contracts.TypedValidator[dnd.NPCOccurrenceList] = (*Validator)(nil)
 var _ pipeline.CheckpointFingerprintProvider = (*Validator)(nil)

 func New(Options) *Validator      { return &Validator{} }
@@ -34,7 +34,7 @@ func (v *Validator) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
 	return []pipeline.CheckpointFingerprint{{Name: "policy", Value: policy}}
 }

-func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCInteractionList]) (contracts.ValidationResult, error) {
+func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCOccurrenceList]) (contracts.ValidationResult, error) {
 	if req.Stage == string(pipeline.StageExtract) && req.Chunk == nil {
 		return contracts.ValidationResult{}, fmt.Errorf("NPC interaction source-reference validator requires the current extraction chunk")
 	}
@@ -43,16 +43,16 @@ func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationReq
 	}
 	index := source.NewDocumentIndex(req.Source)
 	issues := make([]string, 0)
-	for interactionIndex, interaction := range req.Value.Interactions {
-		for refIndex, ref := range interaction.SourceRefs {
+	for occurrenceIndex, occurrence := range req.Value.Occurrences {
+		for refIndex, ref := range occurrence.SourceRefs {
 			if err := index.ValidateRef(ref); err != nil {
-				issues = append(issues, fmt.Sprintf("interactions[%d].source_refs[%d]: %s", interactionIndex, refIndex, diagnostics.Truncate(err.Error())))
+				issues = append(issues, fmt.Sprintf("occurrences[%d].source_refs[%d]: %s", occurrenceIndex, refIndex, diagnostics.Truncate(err.Error())))
 				continue
 			}
 			if req.Stage == string(pipeline.StageExtract) && !chunkContainsRef(req.Chunk, ref) {
 				issues = append(issues, fmt.Sprintf(
-					"interactions[%d].source_refs[%d]: source reference is outside the current extraction chunk",
-					interactionIndex, refIndex,
+					"occurrences[%d].source_refs[%d]: source reference is outside the current extraction chunk",
+					occurrenceIndex, refIndex,
 				))
 			}
 		}
@@ -85,7 +85,7 @@ func Spec() pipeline.ValidatorSpec {
 }

 func Register(registry *pipeline.ValidatorRegistry) error {
-	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCInteractionListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCInteractionList], error) {
+	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCOccurrenceListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCOccurrenceList], error) {
 		options, err := DecodeOptions(request.Options)
 		if err != nil {
 			return nil, err
--- a/internal/modules/dnd/validate/npcinteractions/source_refs/validator_test.go
+++ b/internal/modules/dnd/validate/npcinteractions/source_refs/validator_test.go
@@ -18,13 +18,13 @@ func TestValidatorOwnsCurrentSourceUnitAndRangeValidation(t *testing.T) {
 	if err != nil || !result.Approved {
 		t.Fatalf("valid result = %#v, %v", result, err)
 	}
-	value.Interactions[0].SourceRefs = []source.SourceRef{
+	value.Occurrences[0].SourceRefs = []source.SourceRef{
 		{SourceID: "foreign", StartUnitID: 1, EndUnitID: 1},
 		{SourceID: "session", StartUnitID: 99, EndUnitID: 99},
 		{SourceID: "session", StartUnitID: 2, EndUnitID: 1},
 	}
 	result, err = New(Options{}).Validate(context.Background(), request(document(), value))
-	if err != nil || result.Approved || result.ReasonCode != ReasonCode || !strings.Contains(result.Message, "interactions[0].source_refs[0]") {
+	if err != nil || result.Approved || result.ReasonCode != ReasonCode || !strings.Contains(result.Message, "occurrences[0].source_refs[0]") {
 		t.Fatalf("invalid result = %#v, %v", result, err)
 	}
 }
@@ -37,7 +37,7 @@ func TestValidatorRejectsDocumentValidEvidenceOutsideCurrentExtractionChunk(t *t
 		Units:    append([]source.SourceUnit(nil), doc.Units[:2]...),
 	}
 	value := validList()
-	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{
+	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{
 		Stage:  string(pipeline.StageExtract),
 		Source: doc,
 		Chunk:  chunk,
@@ -47,10 +47,10 @@ func TestValidatorRejectsDocumentValidEvidenceOutsideCurrentExtractionChunk(t *t
 		t.Fatalf("contained evidence = %#v, %v", result, err)
 	}

-	value.Interactions[0].SourceRefs = []source.SourceRef{{
+	value.Occurrences[0].SourceRefs = []source.SourceRef{{
 		SourceID: doc.ID, StartUnitID: 2, EndUnitID: 3,
 	}}
-	result, err = New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{
+	result, err = New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{
 		Stage:  string(pipeline.StageExtract),
 		Source: doc,
 		Chunk:  chunk,
@@ -62,7 +62,7 @@ func TestValidatorRejectsDocumentValidEvidenceOutsideCurrentExtractionChunk(t *t
 }

 func TestValidatorRequiresChunkDuringExtractValidation(t *testing.T) {
-	_, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{
+	_, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{
 		Stage:  string(pipeline.StageExtract),
 		Source: document(),
 		Value:  validList(),
@@ -73,7 +73,7 @@ func TestValidatorRequiresChunkDuringExtractValidation(t *testing.T) {
 }

 func TestValidatorDefersShapeAndDoesNotMutate(t *testing.T) {
-	malformed := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{Name: "Mira Thorn"}}}
+	malformed := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Mira Thorn"}}}
 	result, err := New(Options{}).Validate(context.Background(), request(document(), malformed))
 	if err != nil || !result.Approved {
 		t.Fatalf("shape deferral = %#v, %v", result, err)
@@ -93,17 +93,17 @@ func TestValidatorDefersShapeAndDoesNotMutate(t *testing.T) {
 	}
 }

-func request(doc *source.SourceDocument, value dnd.NPCInteractionList) contracts.TypedValidationRequest[dnd.NPCInteractionList] {
-	return contracts.TypedValidationRequest[dnd.NPCInteractionList]{Source: doc, Value: value}
+func request(doc *source.SourceDocument, value dnd.NPCOccurrenceList) contracts.TypedValidationRequest[dnd.NPCOccurrenceList] {
+	return contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{Source: doc, Value: value}
 }

 func document() *source.SourceDocument {
 	return &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 1}, {ID: 2}, {ID: 3}}}
 }

-func validList() dnd.NPCInteractionList {
-	return dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{
-		Name: "Mira Thorn", Kind: dnd.NPCInteractionKindDialogue,
+func validList() dnd.NPCOccurrenceList {
+	return dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{
+		NPCID: "npc:test", Name: "Mira Thorn", Kind: dnd.NPCOccurrenceKindDialogue,
 		SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 2}},
 	}}}
 }
--- a/internal/modules/dnd/validate/npcinteractions/source_relatedness/validator.go
+++ b/internal/modules/dnd/validate/npcinteractions/source_relatedness/validator.go
@@ -23,7 +23,7 @@ const (
 type Options struct{}
 type Validator struct{}

-var _ contracts.TypedValidator[dnd.NPCInteractionList] = (*Validator)(nil)
+var _ contracts.TypedValidator[dnd.NPCOccurrenceList] = (*Validator)(nil)
 var _ pipeline.CheckpointFingerprintProvider = (*Validator)(nil)

 func New(Options) *Validator      { return &Validator{} }
@@ -35,7 +35,7 @@ func (v *Validator) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
 	return []pipeline.CheckpointFingerprint{{Name: "policy", Value: policy}}
 }

-func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCInteractionList]) (contracts.ValidationResult, error) {
+func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.NPCOccurrenceList]) (contracts.ValidationResult, error) {
 	if interactionshape.Validate(req.Value) != nil {
 		return contracts.ValidationResult{Approved: true}, nil
 	}
@@ -43,23 +43,23 @@ func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationReq
 	if err != nil {
 		return contracts.ValidationResult{Approved: true}, nil
 	}
-	citedTexts := make([]string, len(req.Value.Interactions))
-	for index, interaction := range req.Value.Interactions {
-		citedText, err := resolver.CitedText(interaction.SourceRefs)
+	citedTexts := make([]string, len(req.Value.Occurrences))
+	for index, occurrence := range req.Value.Occurrences {
+		citedText, err := resolver.CitedText(occurrence.SourceRefs)
 		if err != nil {
 			return contracts.ValidationResult{Approved: true}, nil
 		}
 		citedTexts[index] = citedText
 	}
 	warnings := make([]contracts.Warning, 0)
-	for index, interaction := range req.Value.Interactions {
-		if shared.ContainsTokenSequence(citedTexts[index], interaction.Name) {
+	for index, occurrence := range req.Value.Occurrences {
+		if shared.ContainsTokenSequence(citedTexts[index], occurrence.Name) {
 			continue
 		}
 		warnings = append(warnings, contracts.Warning{
-			Scope:      fmt.Sprintf("interactions[%d]", index),
+			Scope:      fmt.Sprintf("occurrences[%d]", index),
 			ReasonCode: WarningReasonCode,
-			Message:    fmt.Sprintf("NPC interaction name %s was not found in cited source text", diagnostics.Quote(interaction.Name)),
+			Message:    fmt.Sprintf("NPC interaction name %s was not found in cited source text", diagnostics.Quote(occurrence.Name)),
 		})
 	}
 	return contracts.ValidationResult{
@@ -73,7 +73,7 @@ func Spec() pipeline.ValidatorSpec {
 }

 func Register(registry *pipeline.ValidatorRegistry) error {
-	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCInteractionListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCInteractionList], error) {
+	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.NPCOccurrenceListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.NPCOccurrenceList], error) {
 		options, err := DecodeOptions(request.Options)
 		if err != nil {
 			return nil, err
--- a/internal/modules/dnd/validate/npcinteractions/source_relatedness/validator_test.go
+++ b/internal/modules/dnd/validate/npcinteractions/source_relatedness/validator_test.go
@@ -14,34 +14,34 @@ import (
 )

 func TestValidatorUsesOnlyCurrentTranscriptAndWarnsOncePerInteraction(t *testing.T) {
-	value := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{
-		{Name: "O'Rin Thorn", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 1}}},
-		{Name: "Missing\nNPC", Kind: dnd.NPCInteractionKindMentioned, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 2, EndUnitID: 2}, {SourceID: "session", StartUnitID: 2, EndUnitID: 2}}},
+	value := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{
+		{NPCID: "npc:test", Name: "O'Rin Thorn", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 1}}},
+		{NPCID: "npc:test", Name: "Missing\nNPC", Kind: dnd.NPCOccurrenceKindMentioned, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 2, EndUnitID: 2}, {SourceID: "session", StartUnitID: 2, EndUnitID: 2}}},
 	}}
 	doc := &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 1, Text: "O’Rin Thorn speaks."}, {ID: 2, Text: "The party waits."}}}
 	references := contracts.ReferenceSet{Slots: map[string]contracts.ResolvedReferenceSlot{"glossary": {Items: []contracts.ReferenceItem{{Content: []byte("Missing NPC")}}}}}
-	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{Source: doc, References: references, Value: value})
+	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{Source: doc, References: references, Value: value})
 	if err != nil || !result.Approved || len(result.Warnings) != 1 {
 		t.Fatalf("Validate() = %#v, %v", result, err)
 	}
-	if warning := result.Warnings[0]; warning.Scope != "interactions[1]" || warning.ReasonCode != WarningReasonCode || !strings.Contains(warning.Message, `Missing\nNPC`) {
+	if warning := result.Warnings[0]; warning.Scope != "occurrences[1]" || warning.ReasonCode != WarningReasonCode || !strings.Contains(warning.Message, `Missing\nNPC`) {
 		t.Fatalf("warning = %#v", warning)
 	}
 }

 func TestValidatorDefersMalformedShapeAndInvalidRanges(t *testing.T) {
-	for _, value := range []dnd.NPCInteractionList{
-		{Interactions: []dnd.NPCInteraction{{Name: "Mira Thorn"}}},
-		{Interactions: []dnd.NPCInteraction{{Name: "Mira Thorn", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 99, EndUnitID: 99}}}}},
+	for _, value := range []dnd.NPCOccurrenceList{
+		{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Mira Thorn"}}},
+		{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Mira Thorn", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 99, EndUnitID: 99}}}}},
 	} {
-		result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{Source: &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 1}}}, Value: value})
+		result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{Source: &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 1}}}, Value: value})
 		if err != nil || !result.Approved || len(result.Warnings) != 0 {
 			t.Fatalf("deferral = %#v, %v", result, err)
 		}
 	}
-	value := dnd.NPCInteractionList{Interactions: []dnd.NPCInteraction{{Name: "Mira Thorn", Kind: dnd.NPCInteractionKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 1}}}}}
+	value := dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{{NPCID: "npc:test", Name: "Mira Thorn", Kind: dnd.NPCOccurrenceKindDialogue, SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 1}}}}}
 	before := value
-	_, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{Source: &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 1, Text: "Mira Thorn"}}}, Value: value})
+	_, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{Source: &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 1, Text: "Mira Thorn"}}}, Value: value})
 	if err != nil || !reflect.DeepEqual(value, before) {
 		t.Fatalf("Validate() mutated value: %#v", value)
 	}
@@ -53,17 +53,18 @@ func TestValidatorDefersMalformedShapeAndInvalidRanges(t *testing.T) {

 func TestValidatorBoundsWarnings(t *testing.T) {
 	count := diagnostics.MaxWarnings + 5
-	interactions := make([]dnd.NPCInteraction, count)
+	interactions := make([]dnd.NPCOccurrence, count)
 	for index := range interactions {
-		interactions[index] = dnd.NPCInteraction{
+		interactions[index] = dnd.NPCOccurrence{
+			NPCID:      "npc:test",
 			Name:       "Missing NPC",
-			Kind:       dnd.NPCInteractionKindMentioned,
+			Kind:       dnd.NPCOccurrenceKindMentioned,
 			SourceRefs: []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 1}},
 		}
 	}
-	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCInteractionList]{
+	result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.NPCOccurrenceList]{
 		Source: &source.SourceDocument{ID: "session", Units: []source.SourceUnit{{ID: 1, Text: "The party waits."}}},
-		Value:  dnd.NPCInteractionList{Interactions: interactions},
+		Value:  dnd.NPCOccurrenceList{Occurrences: interactions},
 	})
 	if err != nil || !result.Approved {
 		t.Fatalf("Validate() = %#v, %v", result, err)
--- a/internal/modules/integration/dnd_npc_interactions_runner_test.go
+++ b/internal/modules/integration/dnd_npc_interactions_runner_test.go
@@ -36,7 +36,7 @@ func TestNPCInteractionPipelineUsesAcceptedRegistryAndCurrentEvidence(t *testing
 	}

 	request := client.requestFor(t, interactionextract.PromptID)
-	wantRegistry := `{"npcs":[{"name":"Mira Thorn"},{"name":"Hooded Guard"}]}`
+	wantRegistry := `{"npcs":[{"id":"` + identity.DeriveID("Mira Thorn") + `","name":"Mira Thorn"},{"id":"` + identity.DeriveID("Hooded Guard") + `","name":"Hooded Guard"}]}`
 	if got := string(request.Inputs["npc_registry"].Content); got != wantRegistry {
 		t.Fatalf("interaction registry input = %s, want names-only projection %s", got, wantRegistry)
 	}
@@ -52,25 +52,25 @@ func TestNPCInteractionPipelineUsesAcceptedRegistryAndCurrentEvidence(t *testing
 	if err != nil {
 		t.Fatalf("Decode(interaction output) error = %v", err)
 	}
-	if len(interactions.Interactions) != 2 {
+	if len(interactions.Occurrences) != 2 {
 		t.Fatalf("interactions = %#v, want two occurrences", interactions)
 	}
-	first, second := interactions.Interactions[0], interactions.Interactions[1]
+	first, second := interactions.Occurrences[0], interactions.Occurrences[1]
 	if first.Name != "Mira Thorn" || string(first.Kind) != "dialogue" || second.Name != "Hooded Guard" || string(second.Kind) != "noncombat_presence" {
 		t.Fatalf("interactions = %#v, want canonical names, kinds, and source chronology", interactions)
 	}
 	assertInteractionEvidence(t, first.SourceRefs)
 	assertInteractionEvidence(t, second.SourceRefs)
 	if first.SourceRefs[0].StartUnitID >= second.SourceRefs[0].StartUnitID {
-		t.Fatalf("interaction chronology = %#v, want source order", interactions.Interactions)
+		t.Fatalf("interaction chronology = %#v, want source order", interactions.Occurrences)
 	}

 	var durable map[string]json.RawMessage
 	if err := json.Unmarshal(serialized.Artifact.Content, &durable); err != nil {
 		t.Fatalf("unmarshal durable interaction payload: %v", err)
 	}
-	if len(durable) != 1 || durable["interactions"] == nil {
-		t.Fatalf("durable interaction payload = %#v, want only interactions", durable)
+	if len(durable) != 1 || durable["occurrences"] == nil {
+		t.Fatalf("durable interaction payload = %#v, want only occurrences", durable)
 	}
 }

@@ -113,8 +113,8 @@ func TestSemanticNPCNormalizationCrossesOrderedRegistryHandoff(t *testing.T) {
 		t.Fatalf("interaction output step = %q, want ordered downstream step", interactionOutput.StepID)
 	}
 	registryRequest := client.requestFor(t, interactionextract.PromptID)
-	if got := string(registryRequest.Inputs["npc_registry"].Content); got != `{"npcs":[{"name":"Mira Thorn"}]}` {
-		t.Fatalf("downstream registry = %s, want one canonical names-only NPC", got)
+	if got := string(registryRequest.Inputs["npc_registry"].Content); got != `{"npcs":[{"id":"`+identity.DeriveID("Mira Thorn")+`","name":"Mira Thorn"}]}` {
+		t.Fatalf("downstream registry = %s, want one canonical NPC identity", got)
 	}
 	manifestContent, err := json.Marshal(output.Manifest)
 	if err != nil {
@@ -228,9 +228,9 @@ func (client *npcInteractionLLMClient) CompleteStructured(ctx context.Context, r
 	case npcnormalize.PromptID:
 		payload = map[string]any{"duplicate_groups": []any{}}
 	case interactionextract.PromptID:
-		payload = map[string]any{"interactions": []any{
-			map[string]any{"name": "Hooded Guard", "kind": "noncombat_presence", "source_refs": []any{map[string]int{"start_unit_id": 3, "end_unit_id": 3}}},
-			map[string]any{"name": " mira thorn ", "kind": "dialogue", "source_refs": []any{map[string]int{"start_unit_id": 2, "end_unit_id": 2}}},
+		payload = map[string]any{"occurrences": []any{
+			map[string]any{"npc_id": identity.DeriveID("Hooded Guard"), "name": "Hooded Guard", "kind": "noncombat_presence", "source_refs": []any{map[string]int{"start_unit_id": 3, "end_unit_id": 3}}},
+			map[string]any{"npc_id": identity.DeriveID("Mira Thorn"), "name": "Mira Thorn", "kind": "dialogue", "source_refs": []any{map[string]int{"start_unit_id": 2, "end_unit_id": 2}}},
 		}}
 	default:
 		return contracts.StructuredCompletionResponse{}, fmt.Errorf("unexpected interaction prompt %q", request.PromptID)
@@ -291,7 +291,7 @@ func (client *semanticNPCInteractionClient) CompleteStructured(_ context.Context
 	case npcnormalize.PromptID:
 		payload = map[string]any{"duplicate_groups": []any{map[string]any{"members": []string{"candidate-000001", "candidate-000002"}, "canonical": "candidate-000001"}}}
 	case interactionextract.PromptID:
-		payload = map[string]any{"interactions": []any{map[string]any{"name": "Mira Thorn", "kind": "dialogue", "source_refs": []any{map[string]int{"start_unit_id": 1, "end_unit_id": 1}}}}}
+		payload = map[string]any{"occurrences": []any{map[string]any{"npc_id": identity.DeriveID("Mira Thorn"), "name": "Mira Thorn", "kind": "dialogue", "source_refs": []any{map[string]int{"start_unit_id": 1, "end_unit_id": 1}}}}}
 	default:
 		return contracts.StructuredCompletionResponse{}, fmt.Errorf("unexpected semantic pipeline prompt %q", request.PromptID)
 	}