diff --git a/packages/events/src/agent-runtime.test.ts b/packages/events/src/agent-runtime.test.ts
index 1d152ce9..8ae570d8 100644
--- a/packages/events/src/agent-runtime.test.ts
+++ b/packages/events/src/agent-runtime.test.ts
@@ -144,8 +144,9 @@ describe('agent runtime contract baseline', () => {
       createdAt: '2026-04-04T12:00:00.000Z',
       statusAtCapture: 'waiting-approval',
       currentTaskId: 'task_cowork_1',
+      checkpointArtifactId: 'artifact://notelett/note-1',
       todoIds: ['todo_cowork_1'],
-      artifactRefs: [],
+      artifactRefs: ['artifact://notelett/note-1'],
       memoryRefs: [],
       approvalRefs: ['approval_1'],
       dispatchContext: {
@@ -164,5 +165,6 @@ describe('agent runtime contract baseline', () => {
 
     expect(checkpoint.statusAtCapture).toBe('waiting-approval');
     expect(checkpoint.resumeToken).toBe('task_cowork_1');
+    expect(checkpoint.checkpointArtifactId).toBe('artifact://notelett/note-1');
   });
 });
diff --git a/packages/events/src/agent-runtime.ts b/packages/events/src/agent-runtime.ts
index a4e38072..5ba0ec96 100644
--- a/packages/events/src/agent-runtime.ts
+++ b/packages/events/src/agent-runtime.ts
@@ -81,6 +81,7 @@ export const AgentCheckpointSchema = z.object({
   createdAt: z.string().datetime(),
   statusAtCapture: AgentCheckpointStatusSchema,
   currentTaskId: z.string().min(1).nullable().optional(),
+  checkpointArtifactId: z.string().min(1).nullable().optional(),
   todoIds: z.array(z.string().min(1)),
   artifactRefs: z.array(z.string().min(1)),
   memoryRefs: z.array(z.string().min(1)),
diff --git a/services/cowork-service/src/modules/agent-runtime/routes.test.ts b/services/cowork-service/src/modules/agent-runtime/routes.test.ts
index e55a65d5..6810506a 100644
--- a/services/cowork-service/src/modules/agent-runtime/routes.test.ts
+++ b/services/cowork-service/src/modules/agent-runtime/routes.test.ts
@@ -89,6 +89,7 @@ describe('agent runtime routes', () => {
             updatedAt: '2026-04-04T08:10:00.000Z',
             sessionId: 'sess-1',
             eventId: 'evt_cowork_task_task-1',
+            checkpointArtifactId: 'artifact://notelett/note-1',
           },
         ],
       },
@@ -102,6 +103,7 @@ describe('agent runtime routes', () => {
       sessionId: 'sess-1',
       productId: 'clawcowork',
       status: 'running',
+      checkpointArtifactId: 'artifact://notelett/note-1',
       correlationId: 'evt_cowork_task_task-1',
     });
   });
@@ -232,6 +234,7 @@ describe('agent runtime routes', () => {
               completed: false,
               cancelled: false,
               completed_tool_calls: 2,
+              checkpoint_artifact_id: 'artifact://notelett/note-1',
               artifact_refs: ['artifact://notelett/note-1'],
               memory_refs: ['memory://mindlyst/memory-1'],
               approval_refs: ['approval://cowork/ap-1'],
@@ -251,6 +254,7 @@ describe('agent runtime routes', () => {
       userId: 'demo-user',
       statusAtCapture: 'queued',
       resumeToken: 'task-1',
+      checkpointArtifactId: 'artifact://notelett/note-1',
       artifactRefs: ['artifact://notelett/note-1'],
       memoryRefs: ['memory://mindlyst/memory-1'],
       approvalRefs: ['approval://cowork/ap-1'],
diff --git a/services/cowork-service/src/modules/agent-runtime/routes.ts b/services/cowork-service/src/modules/agent-runtime/routes.ts
index d64606ff..3a935f15 100644
--- a/services/cowork-service/src/modules/agent-runtime/routes.ts
+++ b/services/cowork-service/src/modules/agent-runtime/routes.ts
@@ -279,6 +279,15 @@ function toAgentCheckpoint(
           : 'checkpoint available for resume',
   ].join('; ');
 
+  const artifactRefs = Array.isArray(checkpoint.artifact_refs)
+    ? checkpoint.artifact_refs.filter((value): value is string => typeof value === 'string')
+    : [];
+  const checkpointArtifactId =
+    typeof checkpoint.checkpoint_artifact_id === 'string' &&
+    checkpoint.checkpoint_artifact_id.length > 0
+      ? checkpoint.checkpoint_artifact_id
+      : (artifactRefs[0] ?? null);
+
   return AgentCheckpointSchema.parse({
     checkpointId: `ckpt_${taskId}`,
     sessionId:
@@ -292,10 +301,9 @@ function toAgentCheckpoint(
     createdAt,
     statusAtCapture: mapCheckpointStatus(task, checkpoint),
     currentTaskId: taskId,
+    checkpointArtifactId,
     todoIds: [`todo_${taskId}`],
-    artifactRefs: Array.isArray(checkpoint.artifact_refs)
-      ? checkpoint.artifact_refs.filter((value): value is string => typeof value === 'string')
-      : [],
+    artifactRefs,
     memoryRefs: Array.isArray(checkpoint.memory_refs)
       ? checkpoint.memory_refs.filter((value): value is string => typeof value === 'string')
       : [],