fix(tui): honor the auto_session_title experimental flag

.changeset/tui-auto-session-title.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Generate AI session titles in the CLI, not just in `kimi web`. With the `auto_session_title` experimental flag on, the TUI now asks for a title once a turn completes, so the session name is a short summary instead of the truncated first prompt.

apps/kimi-code/src/tui/kimi-tui.ts

@@ -303,6 +303,12 @@ interface SendMessageOptions {
 /** How long the one-shot "moved to background" footer hint stays visible. */
 const DETACH_HINT_DISPLAY_MS = 4_000;
 
+/** Engine flag id — see `packages/agent-core-v2/src/session/sessionTitle/flag.ts`. */
+const AUTO_SESSION_TITLE_FLAG = 'auto_session_title';
+
+/** Generation attempts per session before the TUI stops asking, as in the web client. */
+const MAX_SESSION_TITLE_ATTEMPTS = 3;
+
 export class KimiTUI {
   readonly harness: KimiHarness;
   readonly options: KimiTUIOptions;
@@ -316,6 +322,8 @@ export class KimiTUI {
   private readonly approvalController = new ApprovalController();
   private readonly questionController = new QuestionController();
   private readonly reverseRpcDisposers: Array<() => void> = [];
+  /** AI session title bookkeeping, keyed by session id — see maybeGenerateSessionTitle. */
+  private readonly sessionTitleGeneration = new Map<string, { attempts: number; done: boolean }>();
   private skillCommands: readonly KimiSlashCommand[] = [];
   readonly skillCommandMap = new Map<string, string>();
   private pluginCommands: readonly KimiSlashCommand[] = [];
@@ -1731,6 +1739,41 @@ export class KimiTUI {
 
   handleTurnEnded(event: TurnEndedEvent): void {
     this.staging.handleTurnEnded(event);
+    this.maybeGenerateSessionTitle(event);
+  }
+
+  /**
+   * The engine generates an AI session title only when a client asks for one.
+   * `kimi web` asks every time a turn settles; the TUI never asked, so turning
+   * "AI session titles" on in /experiments changed nothing here and the title
+   * stayed the truncated first prompt. Ask on the same trigger and with the
+   * same policy as the web client: the `first_turn` excerpt, at most
+   * MAX_SESSION_TITLE_ATTEMPTS tries per session, and no further tries once one
+   * lands. The rest is already wired — the engine leaves a renamed or already
+   * generated title alone, and the `session.meta.updated` it publishes reaches
+   * the status panel and the terminal title through handleSessionMetaChanged.
+   */
+  private maybeGenerateSessionTitle(event: TurnEndedEvent): void {
+    if (event.reason !== 'completed') return;
+    if (!this.engineV2) return;
+    if (!isExperimentalFlagEnabled(AUTO_SESSION_TITLE_FLAG)) return;
+    const sessionId = this.session?.id;
+    if (sessionId === undefined) return;
+    const state = this.sessionTitleGeneration.get(sessionId);
+    if (state?.done === true) return;
+    const attempts = state?.attempts ?? 0;
+    if (attempts >= MAX_SESSION_TITLE_ATTEMPTS) return;
+    this.sessionTitleGeneration.set(sessionId, { attempts: attempts + 1, done: false });
+    void this.harness
+      .generateSessionTitle({ id: sessionId, source: 'first_turn' })
+      .then((title) => {
+        if (title === undefined) return;
+        this.sessionTitleGeneration.set(sessionId, { attempts: 0, done: true });
+      })
+      .catch(() => {
+        // A title is cosmetic: keep the prompt-derived one and let a later
+        // turn retry while the attempt budget lasts.
+      });
   }
 
   releaseStagingMedia(mediaAttachmentIds: readonly number[]): void {

apps/kimi-code/test/tui/kimi-tui-message-flow.test.ts

@@ -50,6 +50,7 @@ import {
 import { KimiTUI, type KimiTUIStartupInput, type TUIState } from '#/tui/kimi-tui';
 import type { SessionReplayRenderer } from '#/tui/controllers/session-replay';
 import type { StreamingUIController } from '#/tui/controllers/streaming-ui';
+import { setExperimentalFeatures } from '#/tui/commands/experimental-flags';
 import { handleFeedbackCommand } from '#/tui/commands/info';
 import { copyTextToClipboard } from '#/utils/clipboard/clipboard-text';
 import { openUrl } from '#/utils/open-url';
@@ -8530,3 +8531,89 @@ describe('transcript step and assistant folding', () => {
     expect(stripSgr(lastAssistant.render(120).join('\n'))).toContain(`msg-${cycles - 1}`);
   });
 });
+describe('AI session titles', () => {
+  // The flag snapshot is module state shared by every driver in this file.
+  afterEach(() => {
+    setExperimentalFeatures([]);
+  });
+
+  async function makeTitleDriver(
+    generateSessionTitle: ReturnType<typeof vi.fn>,
+    flagEnabled = true,
+  ): Promise<MessageDriver> {
+    const session = makeSession();
+    const { driver } = await makeDriver(
+      session,
+      {
+        getExperimentalFeatures: vi.fn(async () => [
+          { id: 'auto_session_title', enabled: flagEnabled },
+        ]),
+        generateSessionTitle,
+      },
+      { ...makeStartupInput(), engineV2: true },
+    );
+    // The v2 engine starts session-less and creates on first prompt; the turn
+    // events below stand in for that first prompt.
+    await driver.setSession(session);
+    return driver;
+  }
+
+  it('asks the engine to generate a title when a turn completes', async () => {
+    const generateSessionTitle = vi.fn(async () => 'Wire up the terminal title');
+    const driver = await makeTitleDriver(generateSessionTitle);
+
+    emitTurn(driver, 1);
+
+    await vi.waitFor(() => {
+      expect(generateSessionTitle).toHaveBeenCalledWith({
+        id: 'ses-1',
+        source: 'first_turn',
+      });
+    });
+
+    // A generated title is applied once; later turns must not ask again.
+    emitTurn(driver, 2);
+    expect(generateSessionTitle).toHaveBeenCalledTimes(1);
+  });
+
+  it('stays quiet while the experimental flag is off', async () => {
+    const generateSessionTitle = vi.fn(async () => 'Never requested');
+    const driver = await makeTitleDriver(generateSessionTitle, false);
+
+    emitTurn(driver, 1);
+
+    expect(generateSessionTitle).not.toHaveBeenCalled();
+  });
+
+  it('ignores a cancelled turn', async () => {
+    const generateSessionTitle = vi.fn(async () => 'Never requested');
+    const driver = await makeTitleDriver(generateSessionTitle);
+
+    driver.sessionEventHandler.handleEvent(
+      { type: 'turn.started', agentId: 'main', turnId: 1, origin: { kind: 'user' } } as Event,
+      vi.fn(),
+    );
+    driver.sessionEventHandler.handleEvent(
+      { type: 'turn.ended', agentId: 'main', turnId: 1, reason: 'cancelled' } as Event,
+      vi.fn(),
+    );
+
+    expect(generateSessionTitle).not.toHaveBeenCalled();
+  });
+
+  it('gives up after three unproductive attempts', async () => {
+    // `undefined` is what the engine returns when it declines to generate —
+    // no managed login, or the platform request failed.
+    const generateSessionTitle = vi.fn(async () => undefined);
+    const driver = await makeTitleDriver(generateSessionTitle);
+
+    for (const turnId of [1, 2, 3, 4]) {
+      emitTurn(driver, turnId);
+      await vi.waitFor(() => {
+        expect(generateSessionTitle).toHaveBeenCalledTimes(Math.min(turnId, 3));
+      });
+    }
+
+    expect(generateSessionTitle).toHaveBeenCalledTimes(3);
+  });
+});

docs/en/configuration/env-vars.md

@@ -151,6 +151,7 @@ Switches that control the behavior of subsystems such as telemetry, background t
 | `KIMI_CODE_TUI_FULL_SCREEN` | Enable the experimental fullscreen alternate-screen UI: scrollable transcript viewport, mouse text selection, clickable links, and Ctrl-Shift-F transcript search | `1` enables it; anything else keeps the regular inline UI |
 | `KIMI_CODE_EXPERIMENTAL_SECONDARY_MODEL` | Enable the experimental [subagent model pool](./config-files.md#subagent-model-pool) in every launch mode, including the interactive TUI; the master `KIMI_CODE_EXPERIMENTAL_FLAG=1` also enables it | Truthy: `1`/`true`/`yes`/`on`; falsy: `0`/`false`/`no`/`off` |
 | `KIMI_CODE_EXPERIMENTAL_SUBAGENT_FORK` | Enable the experimental `fork` parameter on the `Agent` and `AgentSwarm` tools, letting the model start a subagent with a snapshot of the calling agent's conversation history instead of an empty context; the master `KIMI_CODE_EXPERIMENTAL_FLAG=1` also enables it | Truthy: `1`/`true`/`yes`/`on`; falsy: `0`/`false`/`no`/`off` |
+| `KIMI_CODE_EXPERIMENTAL_AUTO_SESSION_TITLE` | Let the managed `chat_title` tool name the session from the conversation instead of keeping the truncated first prompt; requires a managed Kimi Code OAuth login, and the master `KIMI_CODE_EXPERIMENTAL_FLAG=1` also enables it | Truthy: `1`/`true`/`yes`/`on`; falsy: `0`/`false`/`no`/`off` |
 | `KIMI_MCP_STARTUP_TIMEOUT_MS` | Global default connection timeout (ms) for all MCP servers; takes higher priority than `[mcp] startup_timeout_ms` in `config.toml`, but a per-server `startupTimeoutMs` in `mcp.json` still wins (default `30000`) | Integer from `1` to `2147483647`; invalid values are ignored |
 | `KIMI_MCP_TOOL_TIMEOUT_MS` | Global default single tool-call timeout (ms) for all MCP servers; takes higher priority than `[mcp] tool_timeout_ms` in `config.toml`, but a per-server `toolTimeoutMs` in `mcp.json` still wins (default `60000`) | Integer from `1` to `2147483647`; invalid values are ignored |
 | `KIMI_LOOP_MAX_STEPS_PER_TURN` | Maximum Agent steps per turn; takes higher priority than `[loop_control] max_steps_per_turn` in `config.toml` (unset or `0` means unlimited) | Non-negative integer; invalid values are ignored |

docs/zh/configuration/env-vars.md

@@ -151,6 +151,7 @@ kimi
 | `KIMI_CODE_TUI_FULL_SCREEN` | 启用实验性的 fullscreen alternate-screen 界面：可滚动的 transcript 视口、鼠标选择文本、可点击链接、Ctrl-Shift-F 搜索 | `1` 开启；其他值保持常规内联界面 |
 | `KIMI_CODE_EXPERIMENTAL_SECONDARY_MODEL` | 在包括交互式 TUI 在内的所有启动方式下启用实验性的[subagent 模型池](./config-files.md#subagent-模型池)；master `KIMI_CODE_EXPERIMENTAL_FLAG=1` 也会启用本功能 | 真值：`1`/`true`/`yes`/`on`；假值：`0`/`false`/`no`/`off` |
 | `KIMI_CODE_EXPERIMENTAL_SUBAGENT_FORK` | 在 `Agent` 和 `AgentSwarm` 工具上启用实验性的 `fork` 参数，让模型可以以调用方 Agent 对话历史的快照而不是空上下文启动 subagent；master `KIMI_CODE_EXPERIMENTAL_FLAG=1` 也会启用本功能 | 真值：`1`/`true`/`yes`/`on`；假值：`0`/`false`/`no`/`off` |
+| `KIMI_CODE_EXPERIMENTAL_AUTO_SESSION_TITLE` | 让托管的 `chat_title` 工具根据对话内容生成会话标题，而不是沿用截断后的第一条提示词；需要托管的 Kimi Code OAuth 登录，master `KIMI_CODE_EXPERIMENTAL_FLAG=1` 也会启用本功能 | 真值：`1`/`true`/`yes`/`on`；假值：`0`/`false`/`no`/`off` |
 | `KIMI_MCP_STARTUP_TIMEOUT_MS` | 所有 MCP server 的全局默认连接超时（毫秒）；优先级高于 `config.toml` 的 `[mcp] startup_timeout_ms`，但低于 `mcp.json` 中单个 server 的 `startupTimeoutMs`（默认 `30000`） | `1` 到 `2147483647` 的整数；非法值被忽略 |
 | `KIMI_MCP_TOOL_TIMEOUT_MS` | 所有 MCP server 的全局默认单次工具调用超时（毫秒）；优先级高于 `config.toml` 的 `[mcp] tool_timeout_ms`，但低于 `mcp.json` 中单个 server 的 `toolTimeoutMs`（默认 `60000`） | `1` 到 `2147483647` 的整数；非法值被忽略 |
 | `KIMI_LOOP_MAX_STEPS_PER_TURN` | Agent 单轮最大步数；优先级高于 `config.toml` 的 `[loop_control] max_steps_per_turn`（不设或 `0` 表示无上限） | 非负整数；非法值被忽略 |