From 30271d64ebabd2a9676fc7f8e8987b4a5fe86756 Mon Sep 17 00:00:00 2001
From: Sandy Tao <sandytao520@icloud.com>
Date: Mon, 16 Mar 2026 15:12:28 -0700
Subject: [PATCH] feat(config): enable JIT context loading by default (#22736)

---
 docs/reference/configuration.md           | 2 +-
 packages/cli/src/config/config.test.ts    | 6 +++++-
 packages/cli/src/config/config.ts         | 2 +-
 packages/cli/src/config/settingsSchema.ts | 2 +-
 packages/core/src/config/config.ts        | 2 +-
 schemas/settings.schema.json              | 4 ++--
 6 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/docs/reference/configuration.md b/docs/reference/configuration.md
index 8845b6dd69..a3b4788026 100644
--- a/docs/reference/configuration.md
+++ b/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):
diff --git a/packages/cli/src/config/config.test.ts b/packages/cli/src/config/config.test.ts
index 72c55a64b3..8990224b0f 100644
--- a/packages/cli/src/config/config.test.ts
+++ b/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,
diff --git a/packages/cli/src/config/config.ts b/packages/cli/src/config/config.ts
index ab6a22fb64..c635d5b470 100755
--- a/packages/cli/src/config/config.ts
+++ b/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'] ??
diff --git a/packages/cli/src/config/settingsSchema.ts b/packages/cli/src/config/settingsSchema.ts
index 04db402f07..b06df48bc3 100644
--- a/packages/cli/src/config/settingsSchema.ts
+++ b/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,
       },
diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index f0cf3c1eee..fe3f31edfc 100644
--- a/packages/core/src/config/config.ts
+++ b/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(() =>
diff --git a/schemas/settings.schema.json b/schemas/settings.schema.json
index df802f97a9..1f180ac6dd 100644
--- a/schemas/settings.schema.json
+++ b/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": {