feat(core): experimental in-progress steering hints

docs/get-started/configuration.md

@@ -468,6 +468,19 @@ their corresponding top-level category object in your `settings.json` file.
           }
         }
       },
+      "flash-lite-helper": {
+        "extends": "base",
+        "modelConfig": {
+          "model": "gemini-2.5-flash-lite",
+          "generateContentConfig": {
+            "temperature": 0.2,
+            "maxOutputTokens": 120,
+            "thinkingConfig": {
+              "thinkingBudget": 0
+            }
+          }
+        }
+      },
       "edit-corrector": {
         "extends": "base",
         "modelConfig": {

packages/cli/src/integration-tests/modelSteering.test.tsx

@@ -0,0 +1,80 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, afterEach } from 'vitest';
+import { AppRig } from '../test-utils/AppRig.js';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { PolicyDecision } from '@google/gemini-cli-core';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+describe('Model Steering Integration', () => {
+  let rig: AppRig | undefined;
+
+  afterEach(async () => {
+    await rig?.unmount();
+  });
+
+  it('should steer the model using a hint during a tool turn', async () => {
+    const fakeResponsesPath = path.join(
+      __dirname,
+      '../test-utils/fixtures/steering.responses',
+    );
+    rig = new AppRig({ fakeResponsesPath });
+    await rig.initialize();
+    await rig.waitForIdle();
+
+    rig.setToolPolicy('list_directory', PolicyDecision.ASK_USER);
+    rig.setToolPolicy('read_file', PolicyDecision.ASK_USER);
+
+    rig.setMockCommands([
+      {
+        command: /list_directory/,
+        result: {
+          output: 'file1.txt\nfile2.js\nfile3.md',
+          exitCode: 0,
+        },
+      },
+      {
+        command: /read_file file1.txt/,
+        result: {
+          output: 'This is file1.txt content.',
+          exitCode: 0,
+        },
+      },
+    ]);
+
+    // Start a long task
+    await rig.type('Start long task');
+    await rig.pressEnter();
+
+    // Wait for the model to call 'list_directory' (Confirming state)
+    await rig.waitForOutput('ReadFolder');
+
+    // Injected a hint while the model is in a tool turn
+    rig.addUserHint('focus on .txt');
+
+    // Resolve list_directory (Proceed)
+    await rig.resolveTool('ReadFolder');
+
+    // Wait for the model to process the hint and output the next action
+    // Based on steering.responses, it should first acknowledge the hint
+    await rig.waitForOutput('ACK: I will focus on .txt files now.');
+
+    // Then it should proceed with the next action
+    await rig.waitForOutput(
+      /Since you want me to focus on .txt files,[\s\S]*I will read file1.txt/,
+    );
+    await rig.waitForOutput('ReadFile');
+
+    // Resolve read_file (Proceed)
+    await rig.resolveTool('ReadFile');
+
+    // Wait for final completion
+    await rig.waitForOutput('Task complete.');
+  });
+});

packages/cli/src/test-utils/AppRig.test.tsx

@@ -0,0 +1,40 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, afterEach } from 'vitest';
+import { AppRig } from './AppRig.js';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+describe('AppRig', () => {
+  let rig: AppRig | undefined;
+
+  afterEach(async () => {
+    await rig?.unmount();
+  });
+
+  it('should render the app and handle a simple message', async () => {
+    const fakeResponsesPath = path.join(
+      __dirname,
+      'fixtures',
+      'simple.responses',
+    );
+    rig = new AppRig({ fakeResponsesPath });
+    await rig.initialize();
+
+    // Wait for initial render
+    await rig.waitForOutput('Type your message');
+
+    // Type a message
+    await rig.type('Hello');
+    await rig.pressEnter();
+
+    // Wait for model response
+    await rig.waitForOutput('Hello! How can I help you today?');
+  });
+});