fix: stop recording resume version metadata (#786)

.changeset/clean-resume-metadata.md

@@ -0,0 +1,6 @@
+---
+"@moonshot-ai/agent-core": patch
+"@moonshot-ai/kimi-code": patch
+---
+
+Stop writing resume version markers into persisted agent metadata.

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

@@ -86,7 +86,6 @@ export interface AgentOptions {
   readonly log?: Logger;
   readonly telemetry?: TelemetryClient | undefined;
   readonly pluginSessionStarts?: readonly EnabledPluginSessionStart[];
-  readonly appVersion?: string;
   readonly experimentalFlags?: ExperimentalFlagResolver;
 }
 
@@ -110,7 +109,6 @@ export class Agent {
   readonly hooks?: HookEngine;
   readonly log: Logger;
   readonly telemetry: TelemetryClient;
-  readonly appVersion?: string;
   readonly experimentalFlags: ExperimentalFlagResolver;
 
   readonly blobStore: BlobStore | undefined;
@@ -147,7 +145,6 @@ export class Agent {
     this.subagentHost = options.subagentHost;
     this.mcp = options.mcp;
     this.hooks = options.hookEngine;
-    this.appVersion = options.appVersion;
     this.log = options.log ?? log;
     this.telemetry = options.telemetry ?? noopTelemetryClient;
     this.experimentalFlags = options.experimentalFlags ?? new FlagResolver();

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

@@ -153,7 +153,6 @@ export class AgentRecords {
         type: 'metadata',
         protocol_version: AGENT_WIRE_PROTOCOL_VERSION,
         created_at: Date.now(),
-        app_version: this.agent.appVersion,
       });
       this.metadataInitialized = true;
     }
@@ -217,20 +216,6 @@ export class AgentRecords {
         await this.agent.blobStore.rehydrateParts(msg.content);
       }
     }
-    const firstRecord = replayedRecords[0];
-    if (
-      firstRecord?.type === 'metadata' &&
-      firstRecord.app_version !== this.agent.appVersion
-    ) {
-      this.persistence.append({
-        type: 'metadata',
-        protocol_version: AGENT_WIRE_PROTOCOL_VERSION,
-        created_at: Date.now(),
-        app_version: this.agent.appVersion,
-        resumed: true,
-      });
-      await this.persistence.flush();
-    }
     return { warning };
   }
 

packages/agent-core/src/agent/records/types.ts

@@ -19,8 +19,6 @@ export interface AgentRecordEvents {
   metadata: {
     protocol_version: string;
     created_at: number;
-    app_version?: string;
-    resumed?: boolean;
   };
 
   forked: {};

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

@@ -234,6 +234,7 @@ export class Session {
 
   async resume(): Promise<{ warning?: string }> {
     await this.skillsReady;
+    this.log.info('session resume', { app_version: this.options.appVersion });
     const { agents } = await this.readMetadata();
     this.agents.clear();
     // Only the main agent is needed to reopen the session; subagents replay
@@ -573,7 +574,6 @@ export class Session {
       telemetry: this.telemetry,
       log: this.log.createChild({ agentId: id }),
       pluginSessionStarts: type === 'main' ? this.options.pluginSessionStarts : undefined,
-      appVersion: this.options.appVersion,
       experimentalFlags: this.experimentalFlags,
     });
   }

packages/agent-core/test/agent/records/index.test.ts

@@ -24,6 +24,8 @@ describe('AgentRecords persistence metadata', () => {
       type: 'metadata',
       protocol_version: AGENT_WIRE_PROTOCOL_VERSION,
     });
+    expect(persistence.records[0]).not.toHaveProperty('app_version');
+    expect(persistence.records[0]).not.toHaveProperty('resumed');
     expect(persistence.records[1]?.type).toBe('turn.prompt');
   });
 

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

@@ -21,6 +21,28 @@ const MOCK_PROVIDER = {
 } as const;
 
 describe('Agent resume', () => {
+  it('does not append metadata when resuming records that include legacy app version', async () => {
+    const persistence = new RecordingAgentPersistence([
+      {
+        type: 'metadata',
+        protocol_version: AGENT_WIRE_PROTOCOL_VERSION,
+        created_at: 1,
+        app_version: '0.0.1-old',
+      } as unknown as AgentRecord,
+      {
+        type: 'turn.prompt',
+        input: [{ type: 'text', text: 'old prompt' }],
+        origin: { kind: 'user' },
+      },
+    ]);
+    const ctx = testAgent({ persistence });
+
+    await ctx.agent.resume();
+
+    expect(persistence.appended).toEqual([]);
+    expect(persistence.records.filter((record) => record.type === 'metadata')).toHaveLength(1);
+  });
+
   it('replays persisted records without restarting turns, compactions, plan turns, or tools', async () => {
     const persistence = new RecordingAgentPersistence(resumeHistory());
     const execWithEnv = vi.fn().mockRejectedValue(new Error('Bash should not execute on resume'));

packages/agent-core/test/harness/model-alias-session.test.ts

@@ -11,6 +11,11 @@ import {
   type SDKAPI,
   type TelemetryClient,
 } from '../../src';
+import {
+  __resetRootLoggerForTest,
+  getRootLogger,
+} from '../../src/logging/logger';
+import { resolveLoggingConfig } from '../../src/logging/resolve-config';
 import {
   recordingContextTelemetry,
   type TelemetryContextRecord,
@@ -46,6 +51,7 @@ describe('HarnessAPI session model aliases', () => {
   });
 
   afterEach(async () => {
+    await __resetRootLoggerForTest();
     await rm(tmp, { recursive: true, force: true });
   });
 
@@ -277,6 +283,21 @@ reason = "no rm"
     );
   });
 
+  it('logs app_version when resuming a session', async () => {
+    await getRootLogger().configure(resolveLoggingConfig({ homeDir }));
+    const rpc = await createTestRpc();
+    const created = await rpc.createSession({ workDir, model: 'kimi-code/kimi-for-coding' });
+    await rpc.closeSession({ sessionId: created.id });
+
+    const freshRpc = await createTestRpc({ appVersion: '1.2.3-test' });
+    await freshRpc.resumeSession({ sessionId: created.id });
+    await getRootLogger().flushSession(created.id);
+
+    const logText = await readFile(join(created.sessionDir, 'logs', 'kimi-code.log'), 'utf-8');
+    expect(logText).toContain('session resume');
+    expect(logText).toContain('app_version=1.2.3-test');
+  });
+
   it('surfaces a config error when a resumed model is configured but unresolvable', async () => {
     const rpc = await createTestRpc();
     const created = await rpc.createSession({ workDir, model: 'kimi-code/kimi-for-coding' });
@@ -397,11 +418,17 @@ max_context_size = 1000000
     return join(root, match);
   }
 
-  async function createTestRpc(options: { readonly telemetry?: TelemetryClient } = {}) {
+  async function createTestRpc(
+    options: {
+      readonly appVersion?: string;
+      readonly telemetry?: TelemetryClient;
+    } = {},
+  ) {
     const [coreRpc, sdkRpc] = createRPC<CoreAPI, SDKAPI>();
     void new KimiCore(coreRpc, {
       homeDir,
       configPath,
+      appVersion: options.appVersion,
       telemetry: options.telemetry,
     });
     return sdkRpc({