feat(agent-core): include recent messages in Stop hook payload

.changeset/stop-hook-messages.md

@@ -0,0 +1,9 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Stop hook now includes recent `messages` in its payload, enabling external memory systems like Mimir to learn from the current turn.
+
+- Added `messages` field to the `Stop` hook input data, containing the last user/assistant text messages.
+- Updated the English and Chinese hook documentation.
+- Added a test to verify the payload format.

docs/en/customization/hooks.md

@@ -100,7 +100,7 @@ Only **blockable events** (`PreToolUse`, `Stop`, `UserPromptSubmit`) have return
 | --- | --- | --- | --- |
 | `UserPromptSubmit` | The text submitted by the user | ✓ | Triggered when the user sends a message; returned text is appended to context; if blocked, the model is not called for this turn |
 | `PreToolUse` | Tool name | ✓ | Triggered before a tool call (before permission checks); the tool will not execute if blocked |
-| `Stop` | Empty string | ✓ | Triggered when the model is about to end the current turn; if blocked, a message can be appended to let the model continue |
+| `Stop` | Empty string | ✓ | Triggered when the model is about to end the current turn; the payload includes `messages` (recent user/assistant text) so memory hooks can learn from the turn. If blocked, a message can be appended to let the model continue. |
 | `PostToolUse` | Tool name | — | Triggered after a tool executes successfully (observation only) |
 | `PostToolUseFailure` | Tool name | — | Triggered after a tool fails or is blocked (observation only) |
 | `PermissionRequest` | Tool name | — | Triggered just before waiting for user approval (observation only) |

docs/zh/customization/hooks.md

@@ -100,7 +100,7 @@ Hook 命令的工作目录是当前会话的项目目录。非 Windows 平台上
 | --- | --- | --- | --- |
 | `UserPromptSubmit` | 用户提交的文本内容 | ✓ | 用户发送消息时触发；返回文本会附加到上下文；若阻断，本轮不调用模型 |
 | `PreToolUse` | 工具名 | ✓ | 工具调用前触发（权限检查前）；阻断后工具不会执行 |
-| `Stop` | 空字符串 | ✓ | 模型准备结束本轮时触发；阻断后可追加一条消息让模型继续 |
+| `Stop` | 空字符串 | ✓ | 模型准备结束本轮时触发；payload 包含 `messages`（最近的用户/助手对话文本），外部记忆系统可借此学习本轮内容。若阻断，可追加一条消息让模型继续 |
 | `PostToolUse` | 工具名 | — | 工具成功执行后触发（观察用） |
 | `PostToolUseFailure` | 工具名 | — | 工具失败或被阻断后触发（观察用） |
 | `PermissionRequest` | 工具名 | — | 即将等待用户审批前触发（观察用） |

packages/agent-core/src/agent/turn/index.ts

@@ -738,12 +738,25 @@ export class TurnFlow {
                 return { continue: true };
               }
 
-              // 3. The external Stop hook gets exactly one continuation; the cap
-              //    is intentionally separate from (and does not cap) goal mode.
+              // 3. The external Stop hook gets exactly one continuation; the
+              //    cap is intentionally separate from (and does not cap) goal mode.
               if (!stopHookContinuationUsed) {
+                const stopMessages = this.agent.context.messages
+                  .slice(-10)
+                  .map((msg) => ({
+                    role: msg.role,
+                    content: msg.content
+                      .filter((part) => part.type === 'text')
+                      .map((part) => part.text)
+                      .join(''),
+                  }))
+                  .filter((msg) => msg.role === 'user' || msg.role === 'assistant');
                 const stopBlock = await this.agent.hooks?.triggerBlock('Stop', {
                   signal,
-                  inputData: { stopHookActive: stopHookContinuationUsed },
+                  inputData: {
+                    stopHookActive: stopHookContinuationUsed,
+                    messages: stopMessages,
+                  },
                 });
                 signal.throwIfAborted();
                 if (stopBlock !== undefined) {

packages/agent-core/test/agent/turn.test.ts

@@ -1,4 +1,4 @@
-import { existsSync, mkdtempSync } from 'node:fs';
+import { existsSync, mkdtempSync, readFileSync, writeFileSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'pathe';
 import { setTimeout as delay } from 'node:timers/promises';
@@ -737,6 +737,46 @@ describe('Agent turn flow', () => {
     ]);
   });
 
+  it('includes recent messages in the Stop hook payload', async () => {
+    const dir = mkdtempSync(join(tmpdir(), 'kimi-stop-hook-messages-'));
+    const payloadPath = join(dir, 'stop-payload.json');
+    const scriptPath = join(dir, 'record-stop-payload.cjs');
+    writeFileSync(
+      scriptPath,
+      [
+        "const fs = require('node:fs');",
+        "let input = '';",
+        "process.stdin.on('data', (d) => { input += d; });",
+        "process.stdin.on('end', () => { fs.writeFileSync(process.argv[2], input); });",
+        '',
+      ].join('\n'),
+      'utf-8',
+    );
+    const hookEngine = new HookEngine([
+      {
+        event: 'Stop',
+        command: `node ${JSON.stringify(scriptPath)} ${JSON.stringify(payloadPath)}`,
+      },
+    ]);
+    const ctx = testAgent({ hookEngine });
+    ctx.configure();
+    ctx.mockNextResponse({ type: 'text', text: 'Assistant reply.' });
+
+    await ctx.rpc.prompt({ input: [{ type: 'text', text: 'hello' }] });
+    await ctx.untilTurnEnd();
+
+    const payload = JSON.parse(
+      existsSync(payloadPath) ? readFileSync(payloadPath, 'utf-8') : '{}',
+    );
+    expect(payload.hook_event_name).toBe('Stop');
+    expect(payload.messages).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({ role: 'user', content: 'hello' }),
+        expect.objectContaining({ role: 'assistant', content: 'Assistant reply.' }),
+      ]),
+    );
+  });
+
   it('uses a Stop hook block reason as a one-shot turn continuation', async () => {
     const hookEngine = new HookEngine([
       {