diff --git a/packages/runtime-host/src/__tests__/session-retirement-coordinator.test.ts b/packages/runtime-host/src/__tests__/session-retirement-coordinator.test.ts
index ed61c44fa2..87d08839f9 100644
--- a/packages/runtime-host/src/__tests__/session-retirement-coordinator.test.ts
+++ b/packages/runtime-host/src/__tests__/session-retirement-coordinator.test.ts
@@ -741,6 +741,32 @@ describe('Host Session retirement coordinator', () => {
     });
   });
 
+  test('archives a Session whose Agent Graph is stopped but remains open', async () => {
+    await withHarness(async (harness) => {
+      harness.quiescentGraphs.add(harness.rootId);
+      harness.blockers.graphWake.add(harness.rootId);
+
+      const busy = await harness.coordinator.handlers['session.lifecycle.set'](
+        { sessionId: harness.revisionId, state: 'archived' },
+        CONNECTION_CONTEXT,
+      );
+      assert.equal(busy.ok, false);
+      if (busy.ok) assert.fail('An active supervisor wake must block Session retirement');
+      assert.equal(busy.error.code, 'session_busy');
+      await assertFamilyLifecycle(harness, false);
+
+      harness.blockers.graphWake.clear();
+
+      const outcome = await harness.coordinator.handlers['session.lifecycle.set'](
+        { sessionId: harness.revisionId, state: 'archived' },
+        CONNECTION_CONTEXT,
+      );
+
+      assert.equal(outcome.ok, true);
+      await assertFamilyLifecycle(harness, true);
+    });
+  });
+
   test('retires a bound child worktree only after the Session tombstone commits', async () => {
     await withHarness(async (harness) => {
       const binding = {
@@ -1235,6 +1261,7 @@ async function withHarness(
       graphWake: new Set<string>(),
       scheduledTasks: new Set<string>(),
     };
+    const quiescentGraphs = new Set<string>();
     const memoryExtractionLane = new MemoryExtractionSessionLane();
     const admission = new SessionAdmissionGate();
     const harness: RetirementHarness = {
@@ -1246,6 +1273,7 @@ async function withHarness(
       familyIds: [rootSession.id, revision.id],
       actions,
       blockers,
+      quiescentGraphs,
       admission,
       memoryExtractionLane,
       failRemoveCommit: false,
@@ -1325,7 +1353,12 @@ async function withHarness(
         hasLiveSessionState: (sessionId) => blockers.effect.has(sessionId),
       },
       graph: {
-        hasLiveSessionState: async (sessionId) => blockers.graph.has(sessionId),
+        readRetirementDisposition: async (sessionId) =>
+          blockers.graph.has(sessionId)
+            ? ({ kind: 'busy', status: 'active' } as const)
+            : quiescentGraphs.has(sessionId)
+              ? ({ kind: 'quiescent_open' } as const)
+              : ({ kind: 'clear' } as const),
         listGraphIds: async (sessionId) => [agentGraphIdForRootSession(sessionId)],
       },
       graphWake: {
@@ -1429,6 +1462,7 @@ interface RetirementHarness {
     readonly graphWake: Set<string>;
     readonly scheduledTasks: Set<string>;
   };
+  readonly quiescentGraphs: Set<string>;
   readonly admission: SessionAdmissionGate;
   readonly memoryExtractionLane: MemoryExtractionSessionLane;
   coordinator: HostSessionRetirementCoordinator;
diff --git a/packages/runtime-host/src/server/session-retirement-coordinator.ts b/packages/runtime-host/src/server/session-retirement-coordinator.ts
index 52b672de96..8d6d0d1851 100644
--- a/packages/runtime-host/src/server/session-retirement-coordinator.ts
+++ b/packages/runtime-host/src/server/session-retirement-coordinator.ts
@@ -31,6 +31,7 @@ import {
   type SessionHeaderSnapshot,
 } from '@maka/storage/execution-stores';
 import { type SessionManager } from '@maka/runtime/session-manager';
+import type { AgentGraphRetirementDisposition } from '@maka/runtime/stream-graph-coordinator';
 import type { InteractiveSessionTodoWriter } from '@maka/storage/session-todo-authority';
 import type { InteractiveContextOffloadWriter } from '@maka/storage/context-offload-store';
 import {
@@ -85,7 +86,7 @@ type RetirementSessionEffects = {
   hasLiveSessionState(sessionId: string): boolean;
 };
 type RetirementGraph = {
-  hasLiveSessionState(sessionId: string): Promise<boolean>;
+  readRetirementDisposition(sessionId: string): Promise<AgentGraphRetirementDisposition>;
   listGraphIds(sessionId: string): Promise<readonly string[]>;
 };
 type RetirementGraphWake = {
@@ -660,8 +661,13 @@ export class HostSessionRetirementCoordinator {
         throw new SessionRetirementBusyError(`Session ${sessionId} has a live derived effect`);
       }
       const header = requireFamilyRecord(family, sessionId).header;
-      if (!header.subagentParent && (await this.#graph.hasLiveSessionState(sessionId))) {
-        throw new SessionRetirementBusyError(`Session ${sessionId} has a live Agent Graph`);
+      if (!header.subagentParent) {
+        const graph = await this.#graph.readRetirementDisposition(sessionId);
+        if (graph.kind === 'busy') {
+          throw new SessionRetirementBusyError(
+            `Session ${sessionId} has an Agent Graph that is ${graph.status}`,
+          );
+        }
       }
       if (!header.subagentParent && this.#graphWake.hasLiveSessionState(sessionId)) {
         throw new SessionRetirementBusyError(
diff --git a/packages/runtime/src/__tests__/stream-graph-coordinator.test.ts b/packages/runtime/src/__tests__/stream-graph-coordinator.test.ts
index 4201b6c807..e35b0e2d65 100644
--- a/packages/runtime/src/__tests__/stream-graph-coordinator.test.ts
+++ b/packages/runtime/src/__tests__/stream-graph-coordinator.test.ts
@@ -1364,7 +1364,7 @@ describe('host-managed agent graph coordinator', () => {
     await coordinator.close();
   });
 
-  test('fences retirement from durable open and closing graph state, not a stale client projection', async () => {
+  test('classifies retirement from durable graph state, not a stale client projection', async () => {
     const rootSessionId = 'root-session';
     const childSessionId = 'child-session';
     const graphId = agentGraphIdForRootSession(rootSessionId);
@@ -1390,6 +1390,19 @@ describe('host-managed agent graph coordinator', () => {
       committedAt: 10,
     };
     const workId = addUpdate.addWork[0]!.workId;
+    const stopRequest = compileAgentGraphScheduleUpdate({
+      graphId,
+      input: {
+        operation: 'stop',
+        stop: [{ target_id: workId, reason: 'The work was stopped by the user.' }],
+      },
+      context: toolContext(rootSessionId, 'root-run', 'root-turn', 'stop-work'),
+    });
+    const stopUpdate: AgentGraphScheduleUpdate = {
+      ...stopRequest,
+      revision: 2,
+      committedAt: 20,
+    };
     const finishRequest = compileAgentGraphScheduleUpdate({
       graphId,
       input: {
@@ -1538,16 +1551,74 @@ describe('host-managed agent graph coordinator', () => {
     try {
       assert.equal((await coordinator.getSnapshot(rootSessionId)).scheduleRevision, 0);
       assert.equal(await coordinator.readSessionState(rootSessionId), 'absent');
+      assert.deepEqual(await coordinator.readRetirementDisposition(rootSessionId), {
+        kind: 'clear',
+      });
 
       scheduleUpdates = [addUpdate];
       assert.equal(await coordinator.readSessionState(rootSessionId), 'live');
       assert.equal(await coordinator.hasLiveSessionState(rootSessionId), true);
+      assert.deepEqual(await coordinator.readRetirementDisposition(rootSessionId), {
+        kind: 'busy',
+        status: 'waiting',
+      });
 
-      scheduleUpdates = [addUpdate, finishUpdate];
       provisions = [provision];
       claims = [claim];
+      assert.deepEqual(await coordinator.readRetirementDisposition(rootSessionId), {
+        kind: 'busy',
+        status: 'active',
+      });
+
+      scheduleUpdates = [addUpdate, stopUpdate];
+      runs = [
+        {
+          ...runningRun,
+          terminalEvent: {
+            id: 'child-aborted-terminal',
+            sessionId: childSessionId,
+            invocationId: 'child-invocation',
+            runId,
+            turnId,
+            ts: 14,
+            partial: false,
+            role: 'system',
+            author: 'system',
+            status: 'aborted',
+          },
+        },
+      ];
+      runtimeEvents = [
+        runningEvent,
+        {
+          id: 'child-aborted',
+          invocationId: 'child-invocation',
+          sessionId: childSessionId,
+          runId,
+          turnId,
+          ts: 14,
+          role: 'system',
+          author: 'system',
+          partial: false,
+          status: 'aborted',
+          actions: { endInvocation: true },
+        },
+      ];
+      assert.equal(await coordinator.readSessionState(rootSessionId), 'live');
+      assert.equal(await coordinator.hasLiveSessionState(rootSessionId), true);
+      assert.deepEqual(await coordinator.readRetirementDisposition(rootSessionId), {
+        kind: 'quiescent_open',
+      });
+
+      scheduleUpdates = [addUpdate, finishUpdate];
+      runs = [runningRun];
+      runtimeEvents = [runningEvent];
       assert.equal(await coordinator.readSessionState(rootSessionId), 'live');
       assert.equal(await coordinator.hasLiveSessionState(rootSessionId), true);
+      assert.deepEqual(await coordinator.readRetirementDisposition(rootSessionId), {
+        kind: 'busy',
+        status: 'closing',
+      });
 
       runs = [
         {
@@ -1584,6 +1655,47 @@ describe('host-managed agent graph coordinator', () => {
       ];
       assert.equal(await coordinator.readSessionState(rootSessionId), 'terminal');
       assert.equal(await coordinator.hasLiveSessionState(rootSessionId), false);
+      assert.deepEqual(await coordinator.readRetirementDisposition(rootSessionId), {
+        kind: 'clear',
+      });
+
+      scheduleUpdates = [addUpdate];
+      runs = [
+        {
+          ...runningRun,
+          terminalEvent: {
+            id: 'child-failed-terminal',
+            sessionId: childSessionId,
+            invocationId: 'child-invocation',
+            runId,
+            turnId,
+            ts: 15,
+            partial: false,
+            role: 'system',
+            author: 'system',
+            status: 'failed',
+          },
+        },
+      ];
+      runtimeEvents = [
+        runningEvent,
+        {
+          id: 'child-failed',
+          invocationId: 'child-invocation',
+          sessionId: childSessionId,
+          runId,
+          turnId,
+          ts: 15,
+          role: 'system',
+          author: 'system',
+          partial: false,
+          status: 'failed',
+          actions: { endInvocation: true },
+        },
+      ];
+      assert.deepEqual(await coordinator.readRetirementDisposition(rootSessionId), {
+        kind: 'quiescent_open',
+      });
     } finally {
       await coordinator.close();
     }
diff --git a/packages/runtime/src/stream-graph-coordinator.ts b/packages/runtime/src/stream-graph-coordinator.ts
index 8ebb0885ca..3eb3378e11 100644
--- a/packages/runtime/src/stream-graph-coordinator.ts
+++ b/packages/runtime/src/stream-graph-coordinator.ts
@@ -139,6 +139,11 @@ export interface AgentGraphExecutionStopInput {
   withSupervisorWakesSuppressed(operation: () => Promise<void>): Promise<void>;
 }
 
+export type AgentGraphRetirementDisposition =
+  | { readonly kind: 'clear' }
+  | { readonly kind: 'quiescent_open' }
+  | { readonly kind: 'busy'; readonly status: 'active' | 'waiting' | 'closing' };
+
 interface GraphDriver {
   rootSessionId: string;
   graphId: string;
@@ -391,6 +396,32 @@ export class AgentGraphCoordinator {
     return (await this.readSessionState(rootSessionId)) === 'live';
   }
 
+  /**
+   * Classify durable graph state for Session retirement without changing the
+   * broader live-state semantics used by recovery and graph epoch selection.
+   */
+  async readRetirementDisposition(rootSessionId: string): Promise<AgentGraphRetirementDisposition> {
+    const snapshot = buildAgentGraphClientSnapshot(
+      await this.#readClientModelInputForGraph(
+        rootSessionId,
+        await this.currentGraphId(rootSessionId),
+      ),
+    );
+    if (snapshot.scheduleRevision === 0) return { kind: 'clear' };
+    switch (snapshot.status) {
+      case 'empty':
+      case 'completed':
+        return { kind: 'clear' };
+      case 'stopped':
+      case 'failed':
+        return { kind: 'quiescent_open' };
+      case 'active':
+      case 'waiting':
+      case 'closing':
+        return { kind: 'busy', status: snapshot.status };
+    }
+  }
+
   /**
    * Reconstruct one stable, reference-only control/data-plane timeline page.
    *