diff --git a/packages/core/src/config/config.test.ts b/packages/core/src/config/config.test.ts
index 1fa7bdbf1..67f854be9 100644
--- a/packages/core/src/config/config.test.ts
+++ b/packages/core/src/config/config.test.ts
@@ -8,6 +8,7 @@ import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
 import type { Mock } from 'vitest';
 import type { ConfigParameters, SandboxConfig } from './config.js';
 import { Config, ApprovalMode } from './config.js';
+import * as fs from 'node:fs';
 import * as path from 'node:path';
 import { setGeminiMdFilename as mockSetGeminiMdFilename } from '../tools/memoryTool.js';
 import {
@@ -57,6 +58,9 @@ vi.mock('node:fs', async (importOriginal) => {
       isDirectory: vi.fn().mockReturnValue(true),
     }),
     realpathSync: vi.fn((path) => path),
+    mkdirSync: vi.fn(),
+    writeFileSync: vi.fn(),
+    readFileSync: vi.fn(),
   };
   return {
     ...mocked,
@@ -1240,6 +1244,53 @@ describe('setApprovalMode with folder trust', () => {
     });
   });
 
+  describe('plan file persistence', () => {
+    it('should save plan to disk', () => {
+      const config = new Config(baseParams);
+
+      config.savePlan('# My Plan\n1. Step one\n2. Step two');
+
+      expect(fs.mkdirSync).toHaveBeenCalledWith(
+        expect.stringContaining('plans'),
+        { recursive: true },
+      );
+      expect(fs.writeFileSync).toHaveBeenCalledWith(
+        expect.stringContaining('.md'),
+        '# My Plan\n1. Step one\n2. Step two',
+        'utf-8',
+      );
+    });
+
+    it('should load plan from disk', () => {
+      const config = new Config(baseParams);
+      (fs.readFileSync as Mock).mockReturnValue('# Saved Plan');
+
+      const plan = config.loadPlan();
+      expect(plan).toBe('# Saved Plan');
+    });
+
+    it('should return undefined when no plan file exists', () => {
+      const config = new Config(baseParams);
+      (fs.readFileSync as Mock).mockImplementation(() => {
+        throw new Error('ENOENT');
+      });
+
+      const plan = config.loadPlan();
+      expect(plan).toBeUndefined();
+    });
+
+    it('should use session ID in plan file path', () => {
+      const config = new Config({
+        ...baseParams,
+        sessionId: 'test-session-123',
+      });
+
+      const filePath = config.getPlanFilePath();
+      expect(filePath).toContain('test-session-123');
+      expect(filePath).toMatch(/\.md$/);
+    });
+  });
+
   describe('registerCoreTools', () => {
     beforeEach(() => {
       vi.clearAllMocks();
diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index 27b33cd06..62076887a 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -6,6 +6,7 @@
 
 // Node built-ins
 import type { EventEmitter } from 'node:events';
+import * as fs from 'node:fs';
 import * as path from 'node:path';
 import process from 'node:process';
 
@@ -1665,6 +1666,35 @@ export class Config {
     this.approvalMode = mode;
   }
 
+  /**
+   * Returns the file path for this session's plan file.
+   */
+  getPlanFilePath(): string {
+    return Storage.getPlanFilePath(this.sessionId);
+  }
+
+  /**
+   * Saves a plan to disk for the current session.
+   */
+  savePlan(plan: string): void {
+    const filePath = this.getPlanFilePath();
+    const dir = path.dirname(filePath);
+    fs.mkdirSync(dir, { recursive: true });
+    fs.writeFileSync(filePath, plan, 'utf-8');
+  }
+
+  /**
+   * Loads the plan for the current session, or returns undefined if none exists.
+   */
+  loadPlan(): string | undefined {
+    const filePath = this.getPlanFilePath();
+    try {
+      return fs.readFileSync(filePath, 'utf-8');
+    } catch {
+      return undefined;
+    }
+  }
+
   getInputFormat(): 'text' | 'stream-json' {
     return this.inputFormat;
   }
diff --git a/packages/core/src/config/storage.ts b/packages/core/src/config/storage.ts
index e29cefa62..d14998dec 100644
--- a/packages/core/src/config/storage.ts
+++ b/packages/core/src/config/storage.ts
@@ -18,6 +18,7 @@ const TMP_DIR_NAME = 'tmp';
 const BIN_DIR_NAME = 'bin';
 const PROJECT_DIR_NAME = 'projects';
 const IDE_DIR_NAME = 'ide';
+const PLANS_DIR_NAME = 'plans';
 const DEBUG_DIR_NAME = 'debug';
 const ARENA_DIR_NAME = 'arena';
 
@@ -165,6 +166,14 @@ export class Storage {
     return path.join(Storage.getRuntimeBaseDir(), IDE_DIR_NAME);
   }
 
+  static getPlansDir(): string {
+    return path.join(Storage.getGlobalQwenDir(), PLANS_DIR_NAME);
+  }
+
+  static getPlanFilePath(sessionId: string): string {
+    return path.join(Storage.getPlansDir(), `${sessionId}.md`);
+  }
+
   static getGlobalBinDir(): string {
     return path.join(Storage.getGlobalQwenDir(), BIN_DIR_NAME);
   }
diff --git a/packages/core/src/tools/exitPlanMode.test.ts b/packages/core/src/tools/exitPlanMode.test.ts
index 721069429..022a78fd6 100644
--- a/packages/core/src/tools/exitPlanMode.test.ts
+++ b/packages/core/src/tools/exitPlanMode.test.ts
@@ -22,6 +22,7 @@ describe('ExitPlanModeTool', () => {
       setApprovalMode: vi.fn((mode: ApprovalMode) => {
         approvalMode = mode;
       }),
+      savePlan: vi.fn(),
     } as unknown as Config;
 
     tool = new ExitPlanModeTool(mockConfig);
@@ -148,6 +149,9 @@ describe('ExitPlanModeTool', () => {
         ApprovalMode.DEFAULT,
       );
       expect(approvalMode).toBe(ApprovalMode.DEFAULT);
+
+      // Plan should be saved to disk
+      expect(mockConfig.savePlan).toHaveBeenCalledWith(params.plan);
     });
 
     it('should request confirmation with plan details', async () => {
@@ -222,6 +226,9 @@ describe('ExitPlanModeTool', () => {
         ApprovalMode.PLAN,
       );
       expect(approvalMode).toBe(ApprovalMode.PLAN);
+
+      // Plan should NOT be saved when rejected
+      expect(mockConfig.savePlan).not.toHaveBeenCalled();
     });
 
     it('should have correct description', () => {
diff --git a/packages/core/src/tools/exitPlanMode.ts b/packages/core/src/tools/exitPlanMode.ts
index 123760cf9..b6dd1cdfd 100644
--- a/packages/core/src/tools/exitPlanMode.ts
+++ b/packages/core/src/tools/exitPlanMode.ts
@@ -147,6 +147,15 @@ class ExitPlanModeToolInvocation extends BaseToolInvocation<
         };
       }
 
+      // Persist the approved plan to disk
+      try {
+        this.config.savePlan(plan);
+      } catch (error) {
+        debugLogger.warn(
+          `[ExitPlanModeTool] Failed to save plan to disk: ${error instanceof Error ? error.message : String(error)}`,
+        );
+      }
+
       const llmMessage = `User has approved your plan. You can now start coding. Start with updating your todo list if applicable.`;
       const displayMessage = 'User approved the plan.';