Exclude extension context from skill extraction agent

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']);

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 !== false;
+    const extension = includeExtensionContext
+      ? this.memoryContextManager.getExtensionMemory()
+      : '';
     const project = this.memoryContextManager.getEnvironmentMemory();
     if (extension?.trim()) {
       sections.push(