diff --git a/sdk/ARCHITECTURE.md b/sdk/ARCHITECTURE.md
index 8bc95ed30b..06b3c87799 100644
--- a/sdk/ARCHITECTURE.md
+++ b/sdk/ARCHITECTURE.md
@@ -130,12 +130,16 @@ Completion telemetry is anchored to the assistant's explicit completion
 declaration, not session shutdown. After each agent turn, the local
 runtime inspects `AgentResult.toolCalls` and emits `task.completed` the
 moment a successful `submit_and_exit` (the SDK analog of original
-Cline's `attempt_completion`) is observed. `shutdownSession(...)`
-retains a fallback emission for completed sessions that finished
-without an explicit completion-tool observation, so non-interactive
-runs not using the yolo preset still produce a `task.completed` signal.
-Each session emits at most one `task.completed`. See `DOC.md` for the
-event payload and `source` field.
+Cline's `attempt_completion`) is observed. A single teardown choke
+point (`emitTaskCompletedOnTeardown(...)`) retains a fallback emission
+for sessions whose final turn finished cleanly without an explicit
+completion-tool observation (non-interactive runs not using the yolo
+preset, or hosts that disable `submit_and_exit`). It is invoked from
+every session exit path — both `shutdownSession(...)` and
+`releaseSessionRuntime(...)` — so the emission never depends on which
+teardown branch a stop routes through. Each session emits at most one
+`task.completed`. See `DOC.md` for the event payload and `source`
+field.
 
 ### Hub-Backed Runtime
 
diff --git a/sdk/packages/core/src/runtime/host/local-runtime-host.test.ts b/sdk/packages/core/src/runtime/host/local-runtime-host.test.ts
index 18fdca7625..3e766aa3b2 100644
--- a/sdk/packages/core/src/runtime/host/local-runtime-host.test.ts
+++ b/sdk/packages/core/src/runtime/host/local-runtime-host.test.ts
@@ -6845,6 +6845,18 @@ describe("LocalRuntimeHost", () => {
 				.map(([, payload]) => payload as Record<string, unknown>);
 		}
 
+		function getActiveSession(
+			manager: RuntimeHostUnderTest,
+			sessionId: string,
+		): { status: string } {
+			const sessions = (
+				manager as unknown as { sessions: Map<string, { status: string }> }
+			).sessions;
+			const session = sessions.get(sessionId);
+			if (!session) throw new Error("session was not registered");
+			return session;
+		}
+
 		it("emits task.completed once with source=submit_and_exit when the assistant calls the completion tool in a non-interactive run", async () => {
 			const sessionId = "sess-task-completed-submit-non-interactive";
 			const manifest = createManifest(sessionId);
@@ -7117,6 +7129,287 @@ describe("LocalRuntimeHost", () => {
 			expect(emissions).toHaveLength(1);
 			expect(emissions[0]).toMatchObject({ source: "shutdown" });
 		});
+
+		it("emits task.completed exactly once when a stopped interactive session takes the release path after a clean final turn", async () => {
+			const sessionId = "sess-task-completed-release-path";
+			const manifest = createManifest(sessionId);
+			const adapter = createTaskCompletedAdapter();
+			const telemetry = new TelemetryService({
+				adapters: [adapter],
+				distinctId,
+			});
+			const sessionService = createMockSessionService(manifest);
+			const runtimeBuilder = {
+				build: vi.fn().mockReturnValue({
+					tools: [],
+					shutdown: vi.fn(),
+				}),
+			};
+			const agent = {
+				// Clean final turn without submit_and_exit — records
+				// lastInteractiveTurnFinishReason === "completed".
+				run: vi.fn().mockResolvedValue(createResult({ toolCalls: [] })),
+				continue: vi.fn(),
+				getMessages: vi.fn().mockReturnValue([]),
+				getAgentId: vi.fn().mockReturnValue("agent-root-1"),
+				getConversationId: vi.fn().mockReturnValue("conv-root-1"),
+				abort: vi.fn(),
+				subscribeEvents: vi.fn().mockReturnValue(() => {}),
+				canStartRun: vi.fn().mockReturnValue(true),
+				shutdown: vi.fn().mockResolvedValue(undefined),
+			};
+			const manager = new RuntimeHostUnderTest({
+				distinctId,
+				sessionService: sessionService as never,
+				runtimeBuilder: runtimeBuilder as never,
+				createAgent: () => agent as never,
+				telemetry,
+			});
+
+			await manager.startSession(
+				normalizeStartInput({
+					config: createConfig({ telemetry, sessionId }),
+					prompt: "finish the task cleanly",
+					interactive: true,
+				}),
+			);
+
+			// Truthful status reporting can leave a resident interactive session
+			// with a terminal reported status (e.g. adopted from a resumed
+			// manifest), which routes stopSession through releaseSessionRuntime
+			// instead of shutdownSession.
+			getActiveSession(manager, sessionId).status = "completed";
+			const statusWritesBeforeStop =
+				sessionService.updateSessionStatus.mock.calls.length;
+			await manager.stopSession(sessionId);
+			// The release branch never writes a session status — this proves the
+			// stop really took the path that used to drop the emission.
+			expect(sessionService.updateSessionStatus.mock.calls.length).toBe(
+				statusWritesBeforeStop,
+			);
+
+			const emissions = countTaskCompletedEmissions(adapter);
+			expect(emissions).toHaveLength(1);
+			expect(emissions[0]).toMatchObject({
+				ulid: sessionId,
+				source: "shutdown",
+				provider: "mock-provider",
+				modelId: "mock-model",
+			});
+		});
+
+		it("emits nothing when a released interactive session's final turn aborted", async () => {
+			const sessionId = "sess-task-completed-release-aborted";
+			const manifest = createManifest(sessionId);
+			const adapter = createTaskCompletedAdapter();
+			const telemetry = new TelemetryService({
+				adapters: [adapter],
+				distinctId,
+			});
+			const sessionService = createMockSessionService(manifest);
+			const runtimeBuilder = {
+				build: vi.fn().mockReturnValue({
+					tools: [],
+					shutdown: vi.fn(),
+				}),
+			};
+			const agent = {
+				run: vi
+					.fn()
+					.mockResolvedValue(
+						createResult({ finishReason: "aborted", toolCalls: [] }),
+					),
+				continue: vi.fn(),
+				getMessages: vi.fn().mockReturnValue([]),
+				getAgentId: vi.fn().mockReturnValue("agent-root-1"),
+				getConversationId: vi.fn().mockReturnValue("conv-root-1"),
+				abort: vi.fn(),
+				subscribeEvents: vi.fn().mockReturnValue(() => {}),
+				canStartRun: vi.fn().mockReturnValue(true),
+				shutdown: vi.fn().mockResolvedValue(undefined),
+			};
+			const manager = new RuntimeHostUnderTest({
+				distinctId,
+				sessionService: sessionService as never,
+				runtimeBuilder: runtimeBuilder as never,
+				createAgent: () => agent as never,
+				telemetry,
+			});
+
+			await manager.startSession(
+				normalizeStartInput({
+					config: createConfig({ telemetry, sessionId }),
+					prompt: "turn that gets aborted",
+					interactive: true,
+				}),
+			);
+
+			getActiveSession(manager, sessionId).status = "cancelled";
+			await manager.stopSession(sessionId);
+
+			expect(countTaskCompletedEmissions(adapter)).toHaveLength(0);
+		});
+
+		it("emits nothing when a session's final turn errors after an earlier clean turn", async () => {
+			const sessionId = "sess-task-completed-late-error";
+			const manifest = createManifest(sessionId);
+			const adapter = createTaskCompletedAdapter();
+			const telemetry = new TelemetryService({
+				adapters: [adapter],
+				distinctId,
+			});
+			const sessionService = createMockSessionService(manifest);
+			const runtimeBuilder = {
+				build: vi.fn().mockReturnValue({
+					tools: [],
+					shutdown: vi.fn(),
+				}),
+			};
+			const agent = {
+				// First turn completes cleanly, second turn throws — the errored
+				// turn is the session's final turn, so no task.completed may be
+				// emitted from the stale "completed" of the first turn.
+				run: vi.fn().mockResolvedValue(createResult({ toolCalls: [] })),
+				continue: vi.fn().mockRejectedValue(new Error("provider exploded")),
+				getMessages: vi.fn().mockReturnValue([]),
+				getAgentId: vi.fn().mockReturnValue("agent-root-1"),
+				getConversationId: vi.fn().mockReturnValue("conv-root-1"),
+				abort: vi.fn(),
+				subscribeEvents: vi.fn().mockReturnValue(() => {}),
+				canStartRun: vi.fn().mockReturnValue(true),
+				shutdown: vi.fn().mockResolvedValue(undefined),
+			};
+			const manager = new RuntimeHostUnderTest({
+				distinctId,
+				sessionService: sessionService as never,
+				runtimeBuilder: runtimeBuilder as never,
+				createAgent: () => agent as never,
+				telemetry,
+			});
+
+			await manager.startSession(
+				normalizeStartInput({
+					config: createConfig({ telemetry, sessionId }),
+					prompt: "first turn finishes cleanly",
+					interactive: true,
+				}),
+			);
+			await expect(
+				manager.runTurn({ sessionId, prompt: "second turn blows up" }),
+			).rejects.toThrow("provider exploded");
+
+			expect(countTaskCompletedEmissions(adapter)).toHaveLength(0);
+		});
+
+		it("does not double-fire from the release path after submit_and_exit already emitted", async () => {
+			const sessionId = "sess-task-completed-release-no-double-fire";
+			const manifest = createManifest(sessionId);
+			const adapter = createTaskCompletedAdapter();
+			const telemetry = new TelemetryService({
+				adapters: [adapter],
+				distinctId,
+			});
+			const sessionService = createMockSessionService(manifest);
+			const runtimeBuilder = {
+				build: vi.fn().mockReturnValue({
+					tools: [],
+					shutdown: vi.fn(),
+				}),
+			};
+			const agent = {
+				run: vi.fn().mockResolvedValue(
+					createResult({
+						toolCalls: [createSubmitAndExitToolCall()],
+					}),
+				),
+				continue: vi.fn(),
+				getMessages: vi.fn().mockReturnValue([]),
+				getAgentId: vi.fn().mockReturnValue("agent-root-1"),
+				getConversationId: vi.fn().mockReturnValue("conv-root-1"),
+				abort: vi.fn(),
+				subscribeEvents: vi.fn().mockReturnValue(() => {}),
+				canStartRun: vi.fn().mockReturnValue(true),
+				shutdown: vi.fn().mockResolvedValue(undefined),
+			};
+			const manager = new RuntimeHostUnderTest({
+				distinctId,
+				sessionService: sessionService as never,
+				runtimeBuilder: runtimeBuilder as never,
+				createAgent: () => agent as never,
+				telemetry,
+			});
+
+			await manager.startSession(
+				normalizeStartInput({
+					config: createConfig({ telemetry, sessionId }),
+					prompt: "complete via submit_and_exit",
+					interactive: true,
+				}),
+			);
+
+			getActiveSession(manager, sessionId).status = "completed";
+			await manager.stopSession(sessionId);
+
+			const emissions = countTaskCompletedEmissions(adapter);
+			expect(emissions).toHaveLength(1);
+			expect(emissions[0]).toMatchObject({
+				ulid: sessionId,
+				source: "submit_and_exit",
+			});
+		});
+
+		it("emits task.completed exactly once when dispose() releases a cleanly finished interactive session", async () => {
+			const sessionId = "sess-task-completed-dispose-release";
+			const manifest = createManifest(sessionId);
+			const adapter = createTaskCompletedAdapter();
+			const telemetry = new TelemetryService({
+				adapters: [adapter],
+				distinctId,
+			});
+			const sessionService = createMockSessionService(manifest);
+			const runtimeBuilder = {
+				build: vi.fn().mockReturnValue({
+					tools: [],
+					shutdown: vi.fn(),
+				}),
+			};
+			const agent = {
+				run: vi.fn().mockResolvedValue(createResult({ toolCalls: [] })),
+				continue: vi.fn(),
+				getMessages: vi.fn().mockReturnValue([]),
+				getAgentId: vi.fn().mockReturnValue("agent-root-1"),
+				getConversationId: vi.fn().mockReturnValue("conv-root-1"),
+				abort: vi.fn(),
+				subscribeEvents: vi.fn().mockReturnValue(() => {}),
+				canStartRun: vi.fn().mockReturnValue(true),
+				shutdown: vi.fn().mockResolvedValue(undefined),
+			};
+			const manager = new RuntimeHostUnderTest({
+				distinctId,
+				sessionService: sessionService as never,
+				runtimeBuilder: runtimeBuilder as never,
+				createAgent: () => agent as never,
+				telemetry,
+			});
+
+			await manager.startSession(
+				normalizeStartInput({
+					config: createConfig({ telemetry, sessionId }),
+					prompt: "finish then get disposed",
+					interactive: true,
+				}),
+			);
+
+			getActiveSession(manager, sessionId).status = "completed";
+			await manager.dispose("hub_restart");
+
+			const emissions = countTaskCompletedEmissions(adapter);
+			expect(emissions).toHaveLength(1);
+			expect(emissions[0]).toMatchObject({
+				ulid: sessionId,
+				source: "shutdown",
+			});
+		});
 	});
 
 	describe("LocalRuntimeHost releasing a session mid-run", () => {
diff --git a/sdk/packages/core/src/runtime/host/local-runtime-host.ts b/sdk/packages/core/src/runtime/host/local-runtime-host.ts
index 6db5d2dda8..9fc01f784c 100644
--- a/sdk/packages/core/src/runtime/host/local-runtime-host.ts
+++ b/sdk/packages/core/src/runtime/host/local-runtime-host.ts
@@ -889,6 +889,7 @@ export class LocalRuntimeHost implements RuntimeHost {
 			drainingPendingPrompts: false,
 			pluginSandboxShutdown: bootstrap.pluginSandboxShutdown,
 			submitAndExitObserved: false,
+			taskCompletedEmitted: false,
 			lastInteractiveTurnFinishReason: undefined,
 		};
 		activeSessionRef = active;
@@ -1966,10 +1967,11 @@ export class LocalRuntimeHost implements RuntimeHost {
 	 * `attempt_completion`-driven emission and works for both interactive
 	 * and non-interactive sessions.
 	 *
-	 * `shutdownSession(...)` retains a fallback emission for completed
-	 * sessions that finish without an explicit completion-tool observation
-	 * (e.g., non-interactive runs not using the yolo preset). This helper
-	 * sets `submitAndExitObserved` so the shutdown fallback can suppress a
+	 * `emitTaskCompletedOnTeardown(...)` retains a fallback emission for
+	 * completed sessions that finish without an explicit completion-tool
+	 * observation (e.g., non-interactive runs not using the yolo preset,
+	 * or hosts that disable `submit_and_exit` entirely). This helper sets
+	 * `taskCompletedEmitted` so the teardown fallback can suppress a
 	 * duplicate emission for the same logical completion.
 	 */
 	private observeTaskCompletionTool(
@@ -1984,6 +1986,7 @@ export class LocalRuntimeHost implements RuntimeHost {
 		);
 		if (!completedWithSubmitAndExit) return;
 		session.submitAndExitObserved = true;
+		session.taskCompletedEmitted = true;
 		captureTaskCompleted(session.config.telemetry, {
 			ulid: session.sessionId,
 			provider: session.config.providerId,
@@ -1995,6 +1998,54 @@ export class LocalRuntimeHost implements RuntimeHost {
 		});
 	}
 
+	/**
+	 * Single choke point for the fallback `task.completed` emission on
+	 * session teardown. Every path a session can end through funnels into
+	 * `shutdownSession(...)` or `releaseSessionRuntime(...)`, and BOTH must
+	 * call this helper — the emission must never depend on which teardown
+	 * branch a stop happens to route through. (The 4.1.11 regression:
+	 * truthful session-status reporting re-routed many interactive stops
+	 * onto the release branch, and the fallback that lived only inside
+	 * `shutdownSession` silently stopped firing for them.)
+	 *
+	 * Emits at most once per session (`taskCompletedEmitted`), and never
+	 * after the `submit_and_exit` observer already reported the completion.
+	 * The completion criterion deliberately does not read `session.status`
+	 * (whose lifecycle is what changed in 4.1.11):
+	 *
+	 * - Interactive sessions use the recorded final-turn outcome,
+	 *   `lastInteractiveTurnFinishReason === "completed"`. The extra guards
+	 *   suppress emission when teardown arrives mid-run (the in-flight turn
+	 *   being aborted is the real final turn, and it did not complete).
+	 * - Non-interactive sessions use the terminal status their run result
+	 *   resolved to (`finalStatus`, from `finalizeSingleRun`), preserving
+	 *   the pre-existing `input.status === "completed"` semantics.
+	 *
+	 * Sessions whose final turn errored or aborted emit nothing.
+	 */
+	private emitTaskCompletedOnTeardown(
+		session: ActiveSession,
+		finalStatus?: SessionStatus,
+	): void {
+		if (session.taskCompletedEmitted || session.submitAndExitObserved) return;
+		const completedCleanly = session.interactive
+			? session.lastInteractiveTurnFinishReason === "completed" &&
+				!session.aborting &&
+				session.agent.canStartRun()
+			: finalStatus === "completed";
+		if (!completedCleanly) return;
+		session.taskCompletedEmitted = true;
+		captureTaskCompleted(session.config.telemetry, {
+			ulid: session.sessionId,
+			provider: session.config.providerId,
+			modelId: session.config.modelId,
+			mode: session.config.mode,
+			durationMs: Date.now() - Date.parse(session.startedAt),
+			source: "shutdown",
+			...this.getSessionAgentTelemetryIdentity(session),
+		});
+	}
+
 	private async prepareTurnInput(
 		session: ActiveSession,
 		input: {
@@ -2173,6 +2224,11 @@ export class LocalRuntimeHost implements RuntimeHost {
 	}
 
 	private async failSession(session: ActiveSession): Promise<void> {
+		// The failing turn is this session's final turn. Record it so the
+		// teardown completion criterion (`lastInteractiveTurnFinishReason`)
+		// cannot read a stale "completed" left over from an earlier
+		// successful turn and emit `task.completed` for an errored session.
+		session.lastInteractiveTurnFinishReason = "error";
 		await this.shutdownSession(session, {
 			status: "failed",
 			exitCode: 1,
@@ -2190,21 +2246,11 @@ export class LocalRuntimeHost implements RuntimeHost {
 			endReason: string;
 		},
 	): Promise<void> {
-		// Fallback `task.completed` emission for completed sessions that
-		// did not observe an explicit `submit_and_exit` tool call. The
-		// observer in `executeAgentTurn(...)` already emitted the event in
-		// that case, so we suppress here to avoid double-counting.
-		if (input.status === "completed" && !session.submitAndExitObserved) {
-			captureTaskCompleted(session.config.telemetry, {
-				ulid: session.sessionId,
-				provider: session.config.providerId,
-				modelId: session.config.modelId,
-				mode: session.config.mode,
-				durationMs: Date.now() - Date.parse(session.startedAt),
-				source: "shutdown",
-				...this.getSessionAgentTelemetryIdentity(session),
-			});
-		}
+		// Fallback `task.completed` emission for completed sessions that did
+		// not observe an explicit `submit_and_exit` tool call, routed through
+		// the shared teardown choke point so it can neither double-fire nor
+		// be skipped by teardown routing.
+		this.emitTaskCompletedOnTeardown(session, input.status);
 		notifyTeamRunWaiters(session);
 
 		// Drain an in-flight run before tearing anything down. `stopSession` aborts
@@ -2286,6 +2332,12 @@ export class LocalRuntimeHost implements RuntimeHost {
 		session: ActiveSession,
 		reason: string,
 	): Promise<void> {
+		// Releasing is a full session exit too: interactive sessions whose
+		// reported status is already terminal are stopped/disposed through
+		// this branch. The completion emission must happen here as well —
+		// this is the branch that silently dropped `task.completed` when
+		// truthful status reporting re-routed interactive stops onto it.
+		this.emitTaskCompletedOnTeardown(session);
 		const cleanupErrors: unknown[] = [];
 		const recordCleanupError = (stage: string, error: unknown) => {
 			cleanupErrors.push(error);
diff --git a/sdk/packages/core/src/types/session.ts b/sdk/packages/core/src/types/session.ts
index 972f8f13f7..b929a94a1f 100644
--- a/sdk/packages/core/src/types/session.ts
+++ b/sdk/packages/core/src/types/session.ts
@@ -48,14 +48,21 @@ export type ActiveSession = {
 	 *    declares completion (parity with original Cline's
 	 *    `attempt_completion`).
 	 * 2. Suppress the fallback `task.completed` emission from
-	 *    `shutdownSession(...)` so the same logical completion is not
-	 *    reported twice.
+	 *    `emitTaskCompletedOnTeardown(...)` so the same logical completion
+	 *    is not reported twice.
 	 *
 	 * Non-interactive sessions that finish without ever calling the
-	 * completion tool still receive a `task.completed` from the shutdown
+	 * completion tool still receive a `task.completed` from the teardown
 	 * fallback.
 	 */
 	submitAndExitObserved: boolean;
+	/**
+	 * Set to `true` the moment `task.completed` is emitted for this session,
+	 * whether by the `submit_and_exit` observer or by the teardown fallback
+	 * (`emitTaskCompletedOnTeardown`). Enforces the invariant of exactly one
+	 * `task.completed` per session regardless of which teardown path runs.
+	 */
+	taskCompletedEmitted: boolean;
 };
 
 export type PendingPrompt = {