fix(sdk): count cron turns as replay turn boundaries

.changeset/witty-crabs-tap.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Fix slow response streaming and rendering after resuming sessions with many scheduled cron turns.

packages/node-sdk/src/replay.ts

@@ -113,10 +113,11 @@ function isAgentReplayUserTurnRecord(record: AgentReplayRecord): boolean {
       return message.origin.trigger === 'user-slash';
     case 'shell_command':
       return message.origin.phase === 'input';
-    case 'background_task':
-    case 'compaction_summary':
     case 'cron_job':
     case 'cron_missed':
+      return true;
+    case 'background_task':
+    case 'compaction_summary':
     case 'hook_result':
     case 'injection':
     case 'retry':

packages/node-sdk/test/replay.test.ts

@@ -0,0 +1,128 @@
+import { describe, expect, it } from 'vitest';
+
+import { limitAgentReplayByTurns, type AgentReplayRecord } from '#/replay';
+
+function userTurn(text: string, time: number): AgentReplayRecord {
+  return {
+    type: 'message',
+    time,
+    message: {
+      role: 'user',
+      content: [{ type: 'text', text }],
+      toolCalls: [],
+      origin: { kind: 'user' },
+    },
+  };
+}
+
+function cronTurn(text: string, time: number): AgentReplayRecord {
+  return {
+    type: 'message',
+    time,
+    message: {
+      role: 'user',
+      content: [{ type: 'text', text }],
+      toolCalls: [],
+      origin: { kind: 'cron_job', jobId: 'job-1', cron: '*/15 * * * *', recurring: true, coalescedCount: 1, stale: false },
+    },
+  };
+}
+
+function cronMissedTurn(text: string, time: number): AgentReplayRecord {
+  return {
+    type: 'message',
+    time,
+    message: {
+      role: 'user',
+      content: [{ type: 'text', text }],
+      toolCalls: [],
+      origin: { kind: 'cron_missed', count: 3 },
+    },
+  };
+}
+
+function injection(text: string, time: number): AgentReplayRecord {
+  return {
+    type: 'message',
+    time,
+    message: {
+      role: 'user',
+      content: [{ type: 'text', text }],
+      toolCalls: [],
+      origin: { kind: 'injection', variant: 'reminder' },
+    },
+  };
+}
+
+function assistant(text: string, time: number): AgentReplayRecord {
+  return {
+    type: 'message',
+    time,
+    message: {
+      role: 'assistant',
+      content: [{ type: 'text', text }],
+      toolCalls: [],
+    },
+  };
+}
+
+function replayBytes(records: readonly AgentReplayRecord[]): number {
+  return records.reduce((sum, record) => sum + JSON.stringify(record).length, 0);
+}
+
+describe('limitAgentReplayByTurns', () => {
+  it('keeps only the last N user turns', () => {
+    const records: AgentReplayRecord[] = [];
+    for (let turn = 0; turn < 20; turn++) {
+      records.push(userTurn(`prompt ${turn}`, turn * 10));
+      records.push(assistant(`answer ${turn}`, turn * 10 + 1));
+    }
+    const limited = limitAgentReplayByTurns(records, 5);
+    expect(limited[0]).toMatchObject({ message: { origin: { kind: 'user' } } });
+    expect(JSON.stringify(limited)).toContain('prompt 15');
+    expect(JSON.stringify(limited)).not.toContain('prompt 14');
+  });
+
+  it('bounds replay volume when cron turns dominate the history', () => {
+    const records: AgentReplayRecord[] = [];
+    let time = 0;
+    for (let turn = 0; turn < 30; turn++) {
+      records.push(userTurn(`manual prompt ${turn}`, time++));
+      records.push(assistant('manual answer', time++));
+      for (let cron = 0; cron < 200; cron++) {
+        records.push(cronTurn(`cron fire ${turn}:${cron} ${'x'.repeat(500)}`, time++));
+        records.push(assistant(`cron report ${'y'.repeat(2000)}`, time++));
+      }
+    }
+    const total = replayBytes(records);
+    const limited = limitAgentReplayByTurns(records, 10);
+    expect(limited.length).toBeLessThan(records.length / 10);
+    expect(replayBytes(limited)).toBeLessThan(total / 10);
+    expect(JSON.stringify(limited.at(-2))).toContain('cron fire 29:199');
+  });
+
+  it('treats cron_missed deliveries as turn boundaries', () => {
+    const records: AgentReplayRecord[] = [];
+    for (let turn = 0; turn < 20; turn++) {
+      records.push(cronMissedTurn(`missed ${turn}`, turn * 2));
+      records.push(assistant('report', turn * 2 + 1));
+    }
+    const limited = limitAgentReplayByTurns(records, 5);
+    expect(JSON.stringify(limited)).toContain('missed 15');
+    expect(JSON.stringify(limited)).not.toContain('missed 14');
+  });
+
+  it('does not let injection bursts shrink the window', () => {
+    const records: AgentReplayRecord[] = [];
+    for (let turn = 0; turn < 8; turn++) {
+      records.push(userTurn(`prompt ${turn}`, turn * 100));
+      records.push(assistant(`answer ${turn}`, turn * 100 + 1));
+      for (let i = 0; i < 50; i++) {
+        records.push(injection(`reminder ${turn}:${i}`, turn * 100 + 2 + i));
+      }
+    }
+    const limited = limitAgentReplayByTurns(records, 5);
+    expect(JSON.stringify(limited)).toContain('prompt 3');
+    expect(JSON.stringify(limited)).not.toContain('prompt 2');
+  });
+});