diff --git a/packages/events/src/ecosystem.test.ts b/packages/events/src/ecosystem.test.ts
index c1de536e..6f83cc01 100644
--- a/packages/events/src/ecosystem.test.ts
+++ b/packages/events/src/ecosystem.test.ts
@@ -15,6 +15,7 @@ import {
   Phase1EcosystemEventSchema,
   Phase1EcosystemEventSchemas,
   RoutineArtifactEnvelopeSchema,
+  TrailReportArtifactEnvelopeSchema,
 } from './ecosystem.js';
 
 describe('phase1 ecosystem contracts', () => {
@@ -290,3 +291,111 @@ describe('phase2 ecosystem contract extensions', () => {
     expect(linked.payload.relation).toBe('generated-habit');
   });
 });
+
+describe('phase3 ecosystem contract extensions', () => {
+  it('validates canonical trail-report artifacts', () => {
+    const trailReport = TrailReportArtifactEnvelopeSchema.parse({
+      id: 'art_trail_demo',
+      artifactType: 'trail-report',
+      schemaVersion: 1,
+      productId: 'actiontrail',
+      sourceSurface: 'backend',
+      title: 'Cowork audit report for task task-123',
+      summary: '4 audited actions with 1 safety signal',
+      createdAt: '2026-04-03T14:00:00.000Z',
+      updatedAt: '2026-04-03T14:00:00.000Z',
+      createdBy: { actorType: 'agent', actorId: 'phase3-audit-importer' },
+      ownership: { userId: 'saravana', orgId: null },
+      visibility: {
+        scope: 'private',
+        allowedProducts: ['learning_ai_notes', 'learning_multimodal_memory_agents'],
+      },
+      status: 'recorded',
+      tags: ['ecosystem', 'phase3', 'audit'],
+      links: [],
+      provenance: {
+        originProductId: 'claw-cowork',
+        originActionId: 'task-123',
+        sessionId: 'sess_phase3',
+        runId: 'run_phase3_trail',
+        approvalId: null,
+        correlationId: 'corr_phase3',
+        lineage: [
+          {
+            stepType: 'audit-exported',
+            productId: 'claw-cowork',
+            actorType: 'system',
+            timestamp: '2026-04-03T13:55:00.000Z',
+          },
+          {
+            stepType: 'trail-report-created',
+            productId: 'actiontrail',
+            actorType: 'agent',
+            timestamp: '2026-04-03T14:00:00.000Z',
+          },
+        ],
+      },
+      payload: {
+        sourceProduct: 'claw-cowork',
+        sourceTaskId: 'task-123',
+        generatedFrom: 'audit-export-json',
+        reportGeneratedAt: '2026-04-03T14:00:00.000Z',
+        actionCount: 4,
+        toolCallCount: 2,
+        approvalCount: 1,
+        failureCount: 0,
+        safetySignalCount: 1,
+        tasks: ['task-123'],
+        actionBreakdown: [
+          { action: 'TaskStarted', count: 1 },
+          { action: 'ToolCall', count: 2 },
+          { action: 'InjectionDetected', count: 1 },
+        ],
+        entries: [
+          {
+            timestamp: '2026-04-03T13:55:00.000Z',
+            taskId: 'task-123',
+            action: 'TaskStarted',
+            tool: null,
+            result: 'Success',
+            approval: null,
+            inputSummary: 'Audit seed task',
+            metadata: { surface: 'desktop' },
+          },
+        ],
+      },
+    });
+
+    expect(trailReport.payload.sourceProduct).toBe('claw-cowork');
+    expect(trailReport.payload.safetySignalCount).toBe(1);
+  });
+
+  it('accepts generic artifact.created events for trail-report artifacts', () => {
+    const created = ArtifactCreatedEventSchema.parse({
+      eventId: 'evt_phase3_created',
+      eventName: 'artifact.created',
+      eventVersion: 1,
+      occurredAt: '2026-04-03T14:00:00.000Z',
+      productId: 'actiontrail',
+      sourceSurface: 'backend',
+      userId: 'saravana',
+      orgId: null,
+      sessionId: 'sess_phase3',
+      runId: 'run_phase3_trail',
+      artifactId: 'art_trail_demo',
+      actor: { actorType: 'agent', actorId: 'phase3-audit-importer' },
+      trace: {
+        correlationId: 'corr_phase3',
+        causationId: 'evt_cowork_export',
+        parentEventId: 'evt_cowork_export',
+      },
+      payload: {
+        artifactType: 'trail-report',
+        title: 'Cowork audit report for task task-123',
+        status: 'recorded',
+      },
+    });
+
+    expect(created.payload.artifactType).toBe('trail-report');
+  });
+});
diff --git a/packages/events/src/ecosystem.ts b/packages/events/src/ecosystem.ts
index f72435fe..178ec879 100644
--- a/packages/events/src/ecosystem.ts
+++ b/packages/events/src/ecosystem.ts
@@ -162,6 +162,37 @@ export const HabitPayloadSchema = z.object({
   sourceRoutineId: z.string().min(1),
 });
 
+export const TrailReportPayloadSchema = z.object({
+  sourceProduct: z.literal('claw-cowork'),
+  sourceTaskId: z.string().min(1).nullable().optional(),
+  generatedFrom: z.enum(['audit-export-json', 'audit-query-json']),
+  reportGeneratedAt: z.string().datetime(),
+  actionCount: z.number().int().nonnegative(),
+  toolCallCount: z.number().int().nonnegative(),
+  approvalCount: z.number().int().nonnegative(),
+  failureCount: z.number().int().nonnegative(),
+  safetySignalCount: z.number().int().nonnegative(),
+  tasks: z.array(z.string().min(1)),
+  actionBreakdown: z.array(
+    z.object({
+      action: z.string().min(1),
+      count: z.number().int().positive(),
+    })
+  ),
+  entries: z.array(
+    z.object({
+      timestamp: z.string().datetime(),
+      taskId: z.string().min(1).nullable(),
+      action: z.string().min(1),
+      tool: z.string().min(1).nullable().optional(),
+      result: z.string().min(1).nullable().optional(),
+      approval: z.string().min(1).nullable().optional(),
+      inputSummary: z.string().min(1).nullable().optional(),
+      metadata: z.record(z.unknown()).nullable().optional(),
+    })
+  ),
+});
+
 export const TranscriptArtifactEnvelopeSchema = BaseArtifactEnvelopeSchema.extend({
   artifactType: z.literal('transcript'),
   payload: TranscriptPayloadSchema,
@@ -192,6 +223,11 @@ export const HabitArtifactEnvelopeSchema = BaseArtifactEnvelopeSchema.extend({
   payload: HabitPayloadSchema,
 });
 
+export const TrailReportArtifactEnvelopeSchema = BaseArtifactEnvelopeSchema.extend({
+  artifactType: z.literal('trail-report'),
+  payload: TrailReportPayloadSchema,
+});
+
 export const Phase1ArtifactEnvelopeSchema = z.discriminatedUnion('artifactType', [
   TranscriptArtifactEnvelopeSchema,
   NoteArtifactEnvelopeSchema,
@@ -234,7 +270,15 @@ export const CaptureTranscriptCreatedPayloadSchema = z.object({
 });
 
 export const ArtifactCreatedPayloadSchema = z.object({
-  artifactType: z.enum(['transcript', 'note', 'memory', 'plan', 'routine', 'habit']),
+  artifactType: z.enum([
+    'transcript',
+    'note',
+    'memory',
+    'plan',
+    'routine',
+    'habit',
+    'trail-report',
+  ]),
   title: z.string().min(1).nullable(),
   status: z.string().min(1),
 });