Exclude extension context from skill extraction agent (#26879)

packages/core/src/agents/local-executor.test.ts

@@ -4199,6 +4199,49 @@ describe('LocalAgentExecutor', () => {
         expect(memoryPart).toBeDefined();
         expect(memoryPart?.text).toContain(mockMemory);
       });
+
+      it('should omit extension context from session memory when disabled by the agent', async () => {
+        const definition = createTestDefinition();
+        definition.includeExtensionContext = false;
+        const executor = await LocalAgentExecutor.create(
+          definition,
+          mockConfig,
+          onActivity,
+        );
+
+        const getSessionMemorySpy = vi
+          .spyOn(mockConfig, 'getSessionMemory')
+          .mockImplementation(
+            (options?: { includeExtensionContext?: boolean }) =>
+              options?.includeExtensionContext === false
+                ? '<loaded_context>\n<project_context>\nProject memory rule\n</project_context>\n</loaded_context>'
+                : '<loaded_context>\n<extension_context>\nExtension memory rule\n</extension_context>\n<project_context>\nProject memory rule\n</project_context>\n</loaded_context>',
+          );
+        vi.spyOn(mockConfig, 'isJitContextEnabled').mockReturnValue(true);
+
+        mockModelResponse([
+          {
+            name: COMPLETE_TASK_TOOL_NAME,
+            args: { finalResult: 'done' },
+            id: 'call1',
+          },
+        ]);
+
+        await executor.run({ goal: 'test' }, signal);
+
+        expect(getSessionMemorySpy).toHaveBeenCalledWith({
+          includeExtensionContext: false,
+        });
+        const { message } = getMockMessageParams(0);
+        const parts = message as Part[];
+        const memoryPart = parts.find((p) =>
+          p.text?.includes('<loaded_context>'),
+        );
+
+        expect(memoryPart?.text).toContain('Project memory rule');
+        expect(memoryPart?.text).not.toContain('<extension_context>');
+        expect(memoryPart?.text).not.toContain('Extension memory rule');
+      });
     });
   });
 });

packages/core/src/agents/local-executor.ts

@@ -640,10 +640,19 @@ export class LocalAgentExecutor<TOutput extends z.ZodTypeAny> {
           );
         const formattedInitialHints = formatUserHintsForModel(initialHints);
 
-        // Inject loaded memory files (JIT + extension/project memory)
-        const environmentMemory = this.context.config.isJitContextEnabled?.()
-          ? this.context.config.getSessionMemory()
-          : this.context.config.getEnvironmentMemory();
+        // Inject loaded memory files. Some background agents opt out of
+        // extension memory while still retaining project session context.
+        let environmentMemory: string;
+        if (this.context.config.isJitContextEnabled?.()) {
+          environmentMemory =
+            this.definition.includeExtensionContext === false
+              ? this.context.config.getSessionMemory({
+                  includeExtensionContext: false,
+                })
+              : this.context.config.getSessionMemory();
+        } else {
+          environmentMemory = this.context.config.getEnvironmentMemory();
+        }
 
         const initialParts: Part[] = [];
         if (environmentMemory) {

packages/core/src/agents/skill-extraction-agent.test.ts

@@ -37,6 +37,7 @@ describe('SkillExtractionAgent', () => {
     expect(agent.modelConfig.model).toBe(PREVIEW_GEMINI_FLASH_MODEL);
     expect(agent.memoryInboxAccess).toBe(true);
     expect(agent.autoMemoryExtractionWriteAccess).toBe(true);
+    expect(agent.includeExtensionContext).toBe(false);
     expect(agent.toolConfig?.tools).toEqual(
       expect.arrayContaining([
         READ_FILE_TOOL_NAME,

packages/core/src/agents/skill-extraction-agent.ts

@@ -415,6 +415,7 @@ export const SkillExtractionAgent = (
   },
   memoryInboxAccess: true,
   autoMemoryExtractionWriteAccess: true,
+  includeExtensionContext: false,
   toolConfig: {
     tools: [
       ACTIVATE_SKILL_TOOL_NAME,

packages/core/src/agents/types.ts

@@ -244,6 +244,12 @@ export interface LocalAgentDefinition<
    */
   autoMemoryExtractionWriteAccess?: boolean;
 
+  /**
+   * Controls whether extension memory is injected into this agent's initial
+   * session context when JIT context is enabled. Defaults to true.
+   */
+  includeExtensionContext?: boolean;
+
   /**
    * Optional inline MCP servers for this agent.
    */

packages/core/src/config/config.test.ts

@@ -3525,6 +3525,16 @@ describe('Config JIT Initialization', () => {
     expect(sessionMemory).toContain('</project_context>');
     expect(sessionMemory).toContain('</loaded_context>');
 
+    const sessionMemoryWithoutExtension = config.getSessionMemory({
+      includeExtensionContext: false,
+    });
+    expect(sessionMemoryWithoutExtension).toContain('<loaded_context>');
+    expect(sessionMemoryWithoutExtension).not.toContain('<extension_context>');
+    expect(sessionMemoryWithoutExtension).not.toContain('Extension Memory');
+    expect(sessionMemoryWithoutExtension).toContain('<project_context>');
+    expect(sessionMemoryWithoutExtension).toContain('Environment Memory');
+    expect(sessionMemoryWithoutExtension).toContain('</loaded_context>');
+
     // Verify state update (delegated to MemoryContextManager)
     expect(config.getGeminiMdFileCount()).toBe(1);
     expect(config.getGeminiMdFilePaths()).toEqual(['/path/to/GEMINI.md']);
@@ -3746,6 +3756,8 @@ describe('Config JIT Initialization', () => {
         expect(config.isPathAllowed(privateExtractionPatch)).toBe(true);
         expect(config.validatePathAccess(privateExtractionPatch)).toBeNull();
         expect(config.isPathAllowed(globalExtractionPatch)).toBe(true);
+        // Writes (the default checkType for isPathAllowed) remain restricted
+        // to the canonical extraction.patch filenames.
         expect(
           config.isPathAllowed(path.join(inboxRoot, 'private', 'other.patch')),
         ).toBe(false);
@@ -3754,9 +3766,49 @@ describe('Config JIT Initialization', () => {
             path.join(inboxRoot, 'private', 'nested', 'extraction.patch'),
           ),
         ).toBe(false);
+
+        // Reads are broadened to the .inbox/{private,global}/ subtree so the
+        // extractor can list and inspect prior patches before consolidating.
+        const privateOtherPatch = path.join(
+          inboxRoot,
+          'private',
+          'other.patch',
+        );
+        const globalLeftover = path.join(inboxRoot, 'global', 'topic-a.patch');
+        const nestedReadPath = path.join(
+          inboxRoot,
+          'private',
+          'nested',
+          'extraction.patch',
+        );
+        expect(config.validatePathAccess(privateOtherPatch, 'read')).toBeNull();
+        expect(config.validatePathAccess(globalLeftover, 'read')).toBeNull();
+        expect(config.validatePathAccess(nestedReadPath, 'read')).toBeNull();
+        expect(config.validatePathAccess(inboxRoot, 'read')).toBeNull();
+        expect(
+          config.validatePathAccess(path.join(inboxRoot, 'private'), 'read'),
+        ).toBeNull();
+        expect(
+          config.validatePathAccess(path.join(inboxRoot, 'global'), 'read'),
+        ).toBeNull();
+
+        // Writes to the same broadened paths are still rejected.
+        expect(config.validatePathAccess(privateOtherPatch)).toContain(
+          'Path not in workspace',
+        );
+        expect(config.validatePathAccess(nestedReadPath)).toContain(
+          'Path not in workspace',
+        );
       });
 
       expect(config.isPathAllowed(privateExtractionPatch)).toBe(false);
+      // Outside the scope, reads of inbox files are denied again.
+      expect(
+        config.validatePathAccess(
+          path.join(inboxRoot, 'private', 'other.patch'),
+          'read',
+        ),
+      ).toContain('Path not in workspace');
     });
 
     it('should restrict scoped auto-memory extraction writes to generated artifacts', () => {

packages/core/src/config/config.ts

@@ -2511,12 +2511,15 @@ export class Config implements McpContext, AgentLoopContext {
    * user message when JIT is enabled. Returns empty string when JIT is
    * disabled (Tier 2 memory is already in the system instruction).
    */
-  getSessionMemory(): string {
+  getSessionMemory(options?: { includeExtensionContext?: boolean }): string {
     if (!this.experimentalJitContext || !this.memoryContextManager) {
       return '';
     }
     const sections: string[] = [];
-    const extension = this.memoryContextManager.getExtensionMemory();
+    const includeExtensionContext = options?.includeExtensionContext ?? true;
+    const extension = includeExtensionContext
+      ? this.memoryContextManager.getExtensionMemory()
+      : '';
     const project = this.memoryContextManager.getEnvironmentMemory();
     if (extension?.trim()) {
       sections.push(
@@ -3088,12 +3091,49 @@ export class Config implements McpContext, AgentLoopContext {
     absolutePath: string,
     resolvedPath: string,
     inboxRoot: string,
+    checkType: 'read' | 'write' = 'write',
   ): boolean {
     if (!hasScopedMemoryInboxAccess()) {
       return false;
     }
 
     const normalizedPath = path.resolve(absolutePath);
+    const resolvedMemoryRoot = resolveToRealPath(
+      this.storage.getProjectMemoryTempDir(),
+    );
+
+    // Reads: allow the inbox root and the per-kind subtrees so the extraction
+    // agent can list/inspect prior patches (including non-canonical filenames
+    // left over from older runs) before deciding how to rewrite the canonical
+    // extraction.patch. Writes still flow through the strict canonical-path
+    // check below so the inbox cannot be backdoored with arbitrary files.
+    if (checkType === 'read') {
+      const resolvedInboxRoot = resolveToRealPath(inboxRoot);
+      const normalizedInboxRoot = path.resolve(inboxRoot);
+      if (
+        resolvedPath === resolvedInboxRoot ||
+        normalizedPath === normalizedInboxRoot
+      ) {
+        return isSubpath(resolvedMemoryRoot, resolvedPath);
+      }
+
+      for (const kind of ['private', 'global'] as const) {
+        const kindRoot = path.join(inboxRoot, kind);
+        const resolvedKindRoot = resolveToRealPath(kindRoot);
+        const normalizedKindRoot = path.resolve(kindRoot);
+        if (
+          resolvedPath === resolvedKindRoot ||
+          normalizedPath === normalizedKindRoot ||
+          isSubpath(resolvedKindRoot, resolvedPath) ||
+          isSubpath(normalizedKindRoot, normalizedPath)
+        ) {
+          return isSubpath(resolvedMemoryRoot, resolvedPath);
+        }
+      }
+
+      return false;
+    }
+
     const isCanonicalPatchPath = (['private', 'global'] as const).some(
       (kind) =>
         normalizedPath === path.resolve(inboxRoot, kind, 'extraction.patch'),
@@ -3102,9 +3142,6 @@ export class Config implements McpContext, AgentLoopContext {
       return false;
     }
 
-    const resolvedMemoryRoot = resolveToRealPath(
-      this.storage.getProjectMemoryTempDir(),
-    );
     return isSubpath(resolvedMemoryRoot, resolvedPath);
   }
 
@@ -3148,7 +3185,9 @@ export class Config implements McpContext, AgentLoopContext {
    * the auto-memory extraction agent and the `/memory inbox` review flow. The
    * main agent is denied access to it even though it falls inside the project
    * temp dir; the extraction agent receives a narrow execution-scoped exception
-   * for `.inbox/{private,global}/extraction.patch`.
+   * for *writes* to `.inbox/{private,global}/extraction.patch`. Scoped *read*
+   * access to the wider `.inbox/{private,global}/` subtree is granted in
+   * `validatePathAccess` so the extractor can enumerate prior patches.
    *
    * @param absolutePath The absolute path to check.
    * @returns true if the path is allowed, false otherwise.
@@ -3243,6 +3282,28 @@ export class Config implements McpContext, AgentLoopContext {
       if (this.getWorkspaceContext().isPathReadable(absolutePath)) {
         return null;
       }
+
+      // The memory inbox is carved out of the standard temp-dir allowlist by
+      // `isPathAllowed`. The extraction agent is granted a scoped read
+      // exception so it can enumerate prior patches (including non-canonical
+      // filenames) before consolidating them into the canonical
+      // extraction.patch. Writes remain restricted to canonical paths.
+      if (hasScopedMemoryInboxAccess()) {
+        const inboxRoot = path.join(
+          this.storage.getProjectMemoryTempDir(),
+          '.inbox',
+        );
+        if (
+          this.isScopedMemoryInboxPatchPathAllowed(
+            absolutePath,
+            resolveToRealPath(absolutePath),
+            inboxRoot,
+            'read',
+          )
+        ) {
+          return null;
+        }
+      }
     }
 
     // Then check standard allowed paths (Workspace + Temp)