feat(config): enable JIT context loading by default (#22736)

docs/reference/configuration.md

@@ -1190,7 +1190,7 @@ their corresponding top-level category object in your `settings.json` file.
 
 - **`experimental.jitContext`** (boolean):
   - **Description:** Enable Just-In-Time (JIT) context loading.
-  - **Default:** `false`
+  - **Default:** `true`
   - **Requires restart:** Yes
 
 - **`experimental.useOSC52Paste`** (boolean):

packages/cli/src/config/config.test.ts

@@ -814,7 +814,9 @@ describe('Hierarchical Memory Loading (config.ts) - Placeholder Suite', () => {
 
   it('should pass extension context file paths to loadServerHierarchicalMemory', async () => {
     process.argv = ['node', 'script.js'];
-    const settings = createTestMergedSettings();
+    const settings = createTestMergedSettings({
+      experimental: { jitContext: false },
+    });
     vi.spyOn(ExtensionManager.prototype, 'getExtensions').mockReturnValue([
       {
         path: '/path/to/ext1',
@@ -865,6 +867,7 @@ describe('Hierarchical Memory Loading (config.ts) - Placeholder Suite', () => {
     process.argv = ['node', 'script.js'];
     const includeDir = path.resolve(path.sep, 'path', 'to', 'include');
     const settings = createTestMergedSettings({
+      experimental: { jitContext: false },
       context: {
         includeDirectories: [includeDir],
         loadMemoryFromIncludeDirectories: true,
@@ -892,6 +895,7 @@ describe('Hierarchical Memory Loading (config.ts) - Placeholder Suite', () => {
   it('should NOT pass includeDirectories to loadServerHierarchicalMemory when loadMemoryFromIncludeDirectories is false', async () => {
     process.argv = ['node', 'script.js'];
     const settings = createTestMergedSettings({
+      experimental: { jitContext: false },
       context: {
         includeDirectories: ['/path/to/include'],
         loadMemoryFromIncludeDirectories: false,

packages/cli/src/config/config.ts

@@ -494,7 +494,7 @@ export async function loadCliConfig(
     .getExtensions()
     .find((ext) => ext.isActive && ext.plan?.directory)?.plan;
 
-  const experimentalJitContext = settings.experimental?.jitContext ?? false;
+  const experimentalJitContext = settings.experimental.jitContext;
 
   let extensionRegistryURI =
     process.env['GEMINI_CLI_EXTENSION_REGISTRY_URI'] ??

packages/cli/src/config/settingsSchema.ts

@@ -1894,7 +1894,7 @@ const SETTINGS_SCHEMA = {
         label: 'JIT Context Loading',
         category: 'Experimental',
         requiresRestart: true,
-        default: false,
+        default: true,
         description: 'Enable Just-In-Time (JIT) context loading.',
         showInDialog: false,
       },

packages/core/src/config/config.ts

@@ -994,7 +994,7 @@ export class Config implements McpContext, AgentLoopContext {
       modelConfigServiceConfig ?? DEFAULT_MODEL_CONFIGS,
     );
 
-    this.experimentalJitContext = params.experimentalJitContext ?? false;
+    this.experimentalJitContext = params.experimentalJitContext ?? true;
     this.topicUpdateNarration = params.topicUpdateNarration ?? false;
     this.modelSteering = params.modelSteering ?? false;
     this.injectionService = new InjectionService(() =>

schemas/settings.schema.json

@@ -2013,8 +2013,8 @@
         "jitContext": {
           "title": "JIT Context Loading",
           "description": "Enable Just-In-Time (JIT) context loading.",
-          "markdownDescription": "Enable Just-In-Time (JIT) context loading.\n\n- Category: `Experimental`\n- Requires restart: `yes`\n- Default: `false`",
-          "default": false,
+          "markdownDescription": "Enable Just-In-Time (JIT) context loading.\n\n- Category: `Experimental`\n- Requires restart: `yes`\n- Default: `true`",
+          "default": true,
           "type": "boolean"
         },
         "useOSC52Paste": {