sessions: set session title to first message text immediately (#310345)

roblourens · Copilot · web-flow · commit 9a19d73ce6ee · 2026-04-16T01:45:49.000Z
* sessions: set session title to first message text immediately

When a new agent host session starts, the title shows "New Session" for a
long time until the AI-generated title arrives. Fix this by:

1. Dispatching SessionTitleChanged with the user's message text on the
   first turn in agentSideEffects
2. Overlaying the live title from the state manager in listSessions so
   refreshSessions picks up the updated title instead of the stale SDK value
3. Handling notify/sessionSummaryChanged in both local and remote
   session providers to propagate title changes via the notification channel

Co-authored-by: Copilot &lt;223556219+Copilot@users.noreply.github.com&gt;
(Written by Copilot)

* Simplify: use empty initial title, add unit + integration tests

- Use empty string as initial session title instead of 'New Session'
  sentinel. The UI already falls back to the localized 'New Session'
  label when the title is falsy, so no display change.
- Simplify listSessions overlay: liveTitle || s.summary (natural falsy)
- Simplify side effects check: just turns.length === 0, no string compare
- Remove redundant sessionSummaryChanged notification handlers
- Add 3 unit tests for immediate title dispatch (first turn, whitespace,
  second turn)
- Add 1 unit test for listSessions title overlay
- Add 1 integration test for end-to-end immediate title via WebSocket
- Update existing agent-generated title integration test to expect
  immediate title first

(Written by Copilot)

Co-authored-by: Copilot &lt;223556219+Copilot@users.noreply.github.com&gt;

* Address Copilot review: guard against clobbering existing title

- Only dispatch immediate title when state.summary.title is empty,
  preventing overwrite of user-renamed or provider-set titles
- Add test for the non-empty title guard
- Fix misleading test comment

(Written by Copilot)

Co-authored-by: Copilot &lt;223556219+Copilot@users.noreply.github.com&gt;

* Use DEFAULT_SESSION_TITLE constant instead of empty string

Reverts from empty string to 'New Session' placeholder with a named
constant (DEFAULT_SESSION_TITLE) to avoid blank titles in consumers
using nullish coalescing (`??`) instead of logical OR (`||`).

The side effects check now compares against the constant, and
listSessions overlay skips the default title to avoid overwriting
SDK-reported titles.

Updated PR description to match final implementation (removed
reference to provider-side sessionSummaryChanged handlers).

(Written by Copilot)

Co-authored-by: Copilot &lt;223556219+Copilot@users.noreply.github.com&gt;

* Use empty string initial title, fix ?? consumers to use ||

Reverts to empty string as the initial session title for simplicity.
Fixes downstream consumers that used nullish coalescing (??) to use
logical OR (||) so empty strings correctly fall through to the
fallback label. Also normalizes whitespace and truncates the fallback
title to 200 characters.

Affected consumers:
- agentHostSessionListController.ts
- localAgentHostSessionsProvider.ts
- remoteAgentHostSessionsProvider.ts

(Written by Copilot)

Co-authored-by: Copilot &lt;223556219+Copilot@users.noreply.github.com&gt;

---------

Co-authored-by: Copilot &lt;223556219+Copilot@users.noreply.github.com&gt;
diff --git a/src/vs/platform/agentHost/node/agentService.ts b/src/vs/platform/agentHost/node/agentService.ts
@@ -178,11 +178,19 @@ export class AgentService extends Disposable implements IAgentService {
 			return s;
 		}));
 
-		// Overlay live session status from the state manager
+		// Overlay live session state from the state manager.
+		// For the title, prefer the state manager's value when it is
+		// non-empty, so SDK-sourced titles are not overwritten by the
+		// initial empty placeholder.
 		const withStatus = result.map(s => {
 			const liveState = this._stateManager.getSessionState(s.session.toString());
 			if (liveState) {
-				return { ...s, status: liveState.summary.status, model: liveState.summary.model ?? s.model };
+				return {
+					...s,
+					summary: liveState.summary.title || s.summary,
+					status: liveState.summary.status,
+					model: liveState.summary.model ?? s.model,
+				};
 			}
 			return s;
 		});
@@ -262,7 +270,7 @@ export class AgentService extends Disposable implements IAgentService {
 			const summary: ISessionSummary = {
 				resource: session.toString(),
 				provider: provider.id,
-				title: 'New Session',
+				title: '',
 				status: SessionStatus.Idle,
 				createdAt: Date.now(),
 				modifiedAt: Date.now(),
diff --git a/src/vs/platform/agentHost/node/agentSideEffects.ts b/src/vs/platform/agentHost/node/agentSideEffects.ts
@@ -568,6 +568,22 @@ export class AgentSideEffects extends Disposable {
 				for (const mapper of this._eventMappers.values()) {
 					mapper.reset(action.session);
 				}
+
+				// On the very first turn, immediately set the session title to the
+				// user's message so the UI shows a meaningful title right away
+				// while waiting for the AI-generated title. Only apply when the
+				// title is still the default placeholder to avoid clobbering a
+				// title set by the user or provider before the first turn.
+				const state = this._stateManager.getSessionState(action.session);
+				const fallbackTitle = action.userMessage.text.trim().replace(/\s+/g, ' ').slice(0, 200);
+				if (state && state.turns.length === 0 && !state.summary.title && fallbackTitle.length > 0) {
+					this._stateManager.dispatchServerAction({
+						type: ActionType.SessionTitleChanged,
+						session: action.session,
+						title: fallbackTitle,
+					});
+				}
+
 				const agent = this._options.getAgent(action.session);
 				if (!agent) {
 					this._stateManager.dispatchServerAction({
diff --git a/src/vs/platform/agentHost/test/node/agentService.test.ts b/src/vs/platform/agentHost/test/node/agentService.test.ts
@@ -222,6 +222,23 @@ suite('AgentService (node dispatcher)', () => {
 			assert.strictEqual(sessions[0].summary, 'Auto-generated Title');
 		});
 
+		test('listSessions overlays live state manager title over SDK title', async () => {
+			service.registerProvider(copilotAgent);
+
+			const session = await service.createSession({ provider: 'copilot' });
+
+			// Simulate immediate title change via state manager
+			service.stateManager.dispatchServerAction({
+				type: ActionType.SessionTitleChanged,
+				session: session.toString(),
+				title: 'User first message',
+			});
+
+			const sessions = await service.listSessions();
+			assert.strictEqual(sessions.length, 1);
+			assert.strictEqual(sessions[0].summary, 'User first message');
+		});
+
 		test('createSession stores live session config', async () => {
 			service.registerProvider(copilotAgent);
 
diff --git a/src/vs/platform/agentHost/test/node/agentSideEffects.test.ts b/src/vs/platform/agentHost/test/node/agentSideEffects.test.ts
@@ -130,7 +130,136 @@ suite('AgentSideEffects', () => {
 		});
 	});
 
-	// ---- handleAction: session/turnCancelled ----------------------------
+	// ---- immediate title on first turn -----------------------------------
+
+	suite('immediate title on first turn', () => {
+
+		function setupDefaultSession(): void {
+			stateManager.createSession({
+				resource: sessionUri.toString(),
+				provider: 'mock',
+				title: '',
+				status: SessionStatus.Idle,
+				createdAt: Date.now(),
+				modifiedAt: Date.now(),
+				project: { uri: 'file:///test-project', displayName: 'Test Project' },
+			});
+			stateManager.dispatchServerAction({ type: ActionType.SessionReady, session: sessionUri.toString() });
+		}
+
+		test('dispatches titleChanged with user message on first turn', () => {
+			setupDefaultSession();
+
+			const envelopes: IActionEnvelope[] = [];
+			disposables.add(stateManager.onDidEmitEnvelope(e => envelopes.push(e)));
+
+			sideEffects.handleAction({
+				type: ActionType.SessionTurnStarted,
+				session: sessionUri.toString(),
+				turnId: 'turn-1',
+				userMessage: { text: 'Fix the login bug' },
+			});
+
+			const titleAction = envelopes.find(e => e.action.type === ActionType.SessionTitleChanged);
+			assert.ok(titleAction, 'should dispatch session/titleChanged');
+			if (titleAction?.action.type === ActionType.SessionTitleChanged) {
+				assert.strictEqual(titleAction.action.title, 'Fix the login bug');
+			}
+		});
+
+		test('does not dispatch titleChanged when message is whitespace', () => {
+			setupDefaultSession();
+
+			const envelopes: IActionEnvelope[] = [];
+			disposables.add(stateManager.onDidEmitEnvelope(e => envelopes.push(e)));
+
+			sideEffects.handleAction({
+				type: ActionType.SessionTurnStarted,
+				session: sessionUri.toString(),
+				turnId: 'turn-1',
+				userMessage: { text: '   ' },
+			});
+
+			const titleAction = envelopes.find(e => e.action.type === ActionType.SessionTitleChanged);
+			assert.strictEqual(titleAction, undefined, 'should not dispatch titleChanged for empty message');
+		});
+
+		test('normalizes whitespace and truncates long messages', () => {
+			setupDefaultSession();
+
+			const envelopes: IActionEnvelope[] = [];
+			disposables.add(stateManager.onDidEmitEnvelope(e => envelopes.push(e)));
+
+			const longMessage = 'Fix the bug\nin the login\tpage  please ' + 'a'.repeat(250);
+			sideEffects.handleAction({
+				type: ActionType.SessionTurnStarted,
+				session: sessionUri.toString(),
+				turnId: 'turn-1',
+				userMessage: { text: longMessage },
+			});
+
+			const titleAction = envelopes.find(e => e.action.type === ActionType.SessionTitleChanged);
+			assert.ok(titleAction, 'should dispatch session/titleChanged');
+			if (titleAction?.action.type === ActionType.SessionTitleChanged) {
+				assert.ok(!titleAction.action.title.includes('\n'), 'should not contain newlines');
+				assert.ok(!titleAction.action.title.includes('\t'), 'should not contain tabs');
+				assert.ok(!titleAction.action.title.includes('  '), 'should not contain double spaces');
+				assert.ok(titleAction.action.title.length <= 200, 'should be truncated to 200 chars');
+			}
+		});
+
+		test('does not dispatch titleChanged on second turn', () => {
+			setupDefaultSession();
+			startTurn('turn-1');
+
+			// Complete the first turn so turns.length becomes 1.
+			stateManager.dispatchServerAction({
+				type: ActionType.SessionTurnComplete,
+				session: sessionUri.toString(),
+				turnId: 'turn-1',
+			});
+
+			const envelopes: IActionEnvelope[] = [];
+			disposables.add(stateManager.onDidEmitEnvelope(e => envelopes.push(e)));
+
+			sideEffects.handleAction({
+				type: ActionType.SessionTurnStarted,
+				session: sessionUri.toString(),
+				turnId: 'turn-2',
+				userMessage: { text: 'second message' },
+			});
+
+			const titleAction = envelopes.find(e => e.action.type === ActionType.SessionTitleChanged);
+			assert.strictEqual(titleAction, undefined, 'should not dispatch titleChanged on second turn');
+		});
+
+		test('does not dispatch titleChanged when title is already set', () => {
+			// Session has a non-empty title (e.g. user renamed before first message)
+			stateManager.createSession({
+				resource: sessionUri.toString(),
+				provider: 'mock',
+				title: 'User Renamed',
+				status: SessionStatus.Idle,
+				createdAt: Date.now(),
+				modifiedAt: Date.now(),
+				project: { uri: 'file:///test-project', displayName: 'Test Project' },
+			});
+			stateManager.dispatchServerAction({ type: ActionType.SessionReady, session: sessionUri.toString() });
+
+			const envelopes: IActionEnvelope[] = [];
+			disposables.add(stateManager.onDidEmitEnvelope(e => envelopes.push(e)));
+
+			sideEffects.handleAction({
+				type: ActionType.SessionTurnStarted,
+				session: sessionUri.toString(),
+				turnId: 'turn-1',
+				userMessage: { text: 'hello' },
+			});
+
+			const titleAction = envelopes.find(e => e.action.type === ActionType.SessionTitleChanged);
+			assert.strictEqual(titleAction, undefined, 'should not clobber existing title');
+		});
+	});
 
 	suite('handleAction — session/turnCancelled', () => {
 
diff --git a/src/vs/platform/agentHost/test/node/protocol/sessionFeatures.integrationTest.ts b/src/vs/platform/agentHost/test/node/protocol/sessionFeatures.integrationTest.ts
@@ -77,7 +77,15 @@ suite('Protocol WebSocket — Session Features', function () {
 		const sessionUri = await createAndSubscribeSession(client, 'test-agent-title');
 		dispatchTurnStarted(client, sessionUri, 'turn-title', 'with-title', 1);
 
-		const titleNotif = await client.waitForNotification(n => isActionNotification(n, 'session/titleChanged'));
+		// The first titleChanged is the immediate fallback (user message text).
+		// Wait for the agent-generated title which arrives second.
+		const titleNotif = await client.waitForNotification(n => {
+			if (!isActionNotification(n, 'session/titleChanged')) {
+				return false;
+			}
+			const action = getActionEnvelope(n).action as ITitleChangedAction;
+			return action.title === MOCK_AUTO_TITLE;
+		});
 		const titleAction = getActionEnvelope(titleNotif).action as ITitleChangedAction;
 		assert.strictEqual(titleAction.title, MOCK_AUTO_TITLE);
 
@@ -88,6 +96,31 @@ suite('Protocol WebSocket — Session Features', function () {
 		assert.strictEqual(state.summary.title, MOCK_AUTO_TITLE);
 	});
 
+	test('first turn immediately sets title to user message', async function () {
+		this.timeout(10_000);
+
+		const sessionUri = await createAndSubscribeSession(client, 'test-immediate-title');
+
+		// Verify the session starts with the default placeholder title
+		const before = await client.call<ISubscribeResult>('subscribe', { resource: sessionUri });
+		assert.strictEqual((before.snapshot.state as ISessionState).summary.title, '');
+
+		// Send first turn — side effects should dispatch an immediate titleChanged
+		// with the user's message text before the agent produces its own title.
+		dispatchTurnStarted(client, sessionUri, 'turn-immediate', 'Fix the login bug', 1);
+
+		// The first titleChanged should carry the user message text
+		const titleNotif = await client.waitForNotification(n => isActionNotification(n, 'session/titleChanged'));
+		const titleAction = getActionEnvelope(titleNotif).action as ITitleChangedAction;
+		assert.strictEqual(titleAction.title, 'Fix the login bug');
+
+		// listSessions should also reflect the updated title
+		const result = await client.call<IListSessionsResult>('listSessions');
+		const session = result.items.find(s => s.resource === sessionUri);
+		assert.ok(session, 'session should appear in listSessions');
+		assert.strictEqual(session.title, 'Fix the login bug');
+	});
+
 	test('renamed session title persists across listSessions', async function () {
 		this.timeout(10_000);
 
diff --git a/src/vs/platform/agentHost/test/node/protocolServerHandler.test.ts b/src/vs/platform/agentHost/test/node/protocolServerHandler.test.ts
@@ -9,7 +9,7 @@ import { DisposableStore } from '../../../../base/common/lifecycle.js';
 import { URI } from '../../../../base/common/uri.js';
 import { ensureNoDisposablesAreLeakedInTestSuite } from '../../../../base/test/common/utils.js';
 import { NullLogService } from '../../../log/common/log.js';
-import type { IAgentCreateSessionConfig, IAgentResolveSessionConfigParams, IAgentService, IAgentSessionConfigCompletionsParams, IAgentSessionMetadata, IAuthenticateParams, IAuthenticateResult } from '../../common/agentService.js';
+import { type IAgentCreateSessionConfig, type IAgentResolveSessionConfigParams, type IAgentService, type IAgentSessionConfigCompletionsParams, type IAgentSessionMetadata, type IAuthenticateParams, type IAuthenticateResult } from '../../common/agentService.js';
 import { IListSessionsResult, IResourceReadResult, IResolveSessionConfigResult, ISessionConfigCompletionsResult } from '../../common/state/protocol/commands.js';
 import { ActionType, type ISessionAction } from '../../common/state/sessionActions.js';
 import { PROTOCOL_VERSION } from '../../common/state/sessionCapabilities.js';
@@ -95,7 +95,7 @@ class MockAgentService implements IAgentService {
 		this._stateManager.createSession({
 			resource: session.toString(),
 			provider: config?.provider ?? 'copilot',
-			title: 'New Session',
+			title: '',
 			status: SessionStatus.Idle,
 			createdAt: Date.now(),
 			modifiedAt: Date.now(),
diff --git a/src/vs/sessions/contrib/localAgentHost/browser/localAgentHostSessionsProvider.ts b/src/vs/sessions/contrib/localAgentHost/browser/localAgentHostSessionsProvider.ts
@@ -112,7 +112,7 @@ class LocalSessionAdapter implements ISession {
 		this.providerId = providerId;
 		this.sessionType = logicalSessionType;
 		this.createdAt = new Date(metadata.startTime);
-		this.title = observableValue('title', metadata.summary ?? `Session ${rawId.substring(0, 8)}`);
+		this.title = observableValue('title', metadata.summary || `Session ${rawId.substring(0, 8)}`);
 		this.updatedAt = observableValue('updatedAt', new Date(metadata.modifiedTime));
 		this.modelId = observableValue<string | undefined>('modelId', metadata.model ? `${logicalSessionType}:${metadata.model}` : undefined);
 		this.lastTurnEnd = observableValue('lastTurnEnd', metadata.modifiedTime ? new Date(metadata.modifiedTime) : undefined);
diff --git a/src/vs/sessions/contrib/remoteAgentHost/browser/remoteAgentHostSessionsProvider.ts b/src/vs/sessions/contrib/remoteAgentHost/browser/remoteAgentHostSessionsProvider.ts
@@ -195,7 +195,7 @@ class RemoteSessionAdapter implements IChatData {
 		this.providerId = providerId;
 		this.sessionType = logicalSessionType;
 		this.createdAt = new Date(metadata.startTime);
-		this.title = observableValue('title', metadata.summary ?? `Session ${rawId.substring(0, 8)}`);
+		this.title = observableValue('title', metadata.summary || `Session ${rawId.substring(0, 8)}`);
 		this.updatedAt = observableValue('updatedAt', new Date(metadata.modifiedTime));
 		this.modelId = observableValue<string | undefined>('modelId', metadata.model ? `${resourceScheme}:${metadata.model}` : undefined);
 		this.lastTurnEnd = observableValue('lastTurnEnd', metadata.modifiedTime ? new Date(metadata.modifiedTime) : undefined);
@@ -214,7 +214,7 @@ class RemoteSessionAdapter implements IChatData {
 	}
 
 	update(metadata: IAgentSessionMetadata): void {
-		this.title.set(metadata.summary ?? this.title.get(), undefined);
+		this.title.set(metadata.summary || this.title.get(), undefined);
 		this.updatedAt.set(new Date(metadata.modifiedTime), undefined);
 		this.lastTurnEnd.set(metadata.modifiedTime ? new Date(metadata.modifiedTime) : undefined, undefined);
 		if (metadata.isRead !== undefined) {
diff --git a/src/vs/workbench/contrib/chat/browser/agentSessions/agentHost/agentHostSessionListController.ts b/src/vs/workbench/contrib/chat/browser/agentSessions/agentHost/agentHostSessionListController.ts
@@ -171,7 +171,7 @@ export class AgentHostSessionListController extends Disposable implements IChatS
 	}): IChatSessionItem {
 		return {
 			resource: URI.from({ scheme: this._sessionType, path: `/${rawId}` }),
-			label: opts.title ?? `Session ${rawId.substring(0, 8)}`,
+			label: opts.title || `Session ${rawId.substring(0, 8)}`,
 			description: this._description,
 			iconPath: getAgentHostIcon(this._productService),
 			status: mapSessionStatus(opts.status),
