Add model steering docs.

docs/cli/model-steering.md

@@ -0,0 +1,79 @@
+# Model steering (experimental)
+
+Model steering lets you provide real-time guidance and feedback to Gemini CLI
+while it is actively executing a task. This allows you to correct course, add
+missing context, or skip unnecessary steps without having to stop and restart
+the agent.
+
+> **Note:** This is a preview feature currently under active development. It is
+> only available on the preview channel.
+
+Model steering is particularly useful during complex [Plan Mode](./plan-mode.md)
+workflows or long-running subagent executions where you want to ensure the agent
+stays on the right track.
+
+## Enabling model steering
+
+Model steering is an experimental feature and is disabled by default. You can
+enable it using the `/settings` command or by updating your `settings.json`
+file.
+
+1.  Type `/settings` in the Gemini CLI.
+2.  Search for **Model Steering**.
+3.  Set the value to **true**.
+
+Alternatively, add the following to your `settings.json`:
+
+```json
+{
+  "experimental": {
+    "modelSteering": true
+  }
+}
+```
+
+## Using model steering
+
+When model steering is enabled, Gemini CLI treats any text you type while the
+agent is working as a steering hint.
+
+1.  Start a task (for example, "Refactor the database service").
+2.  While the agent is working (the spinner is visible), type your feedback in
+    the input box.
+3.  Press **Enter**.
+
+Gemini CLI acknowledges your hint with a brief message and injects it directly
+into the model's context for the very next turn. The model then re-evaluates its
+current plan and adjusts its actions accordingly.
+
+### Common use cases
+
+You can use steering hints to guide the model in several ways:
+
+- **Correcting a path:** "Actually, the utilities are in `src/common/utils`."
+- **Skipping a step:** "Skip the unit tests for now and just focus on the
+  implementation."
+- **Adding context:** "The `User` type is defined in `packages/core/types.ts`."
+- **Redirecting the effort:** "Stop searching the codebase and start drafting
+  the plan now."
+- **Handling ambiguity:** "Use the existing `Logger` class instead of creating a
+  new one."
+
+## How it works
+
+When you submit a steering hint, Gemini CLI performs the following actions:
+
+1.  **Immediate acknowledgement:** It uses a small, fast model to generate a
+    one-sentence acknowledgment so you know your hint was received.
+2.  **Context injection:** It prepends an internal instruction to your hint that
+    tells the main agent to:
+    - Re-evaluate the active plan.
+    - Classify the update (for example, as a new task or extra context).
+    - Apply minimal-diff changes to affected tasks.
+3.  **Real-time update:** The hint is delivered to the agent at the beginning of
+    its next turn, ensuring the most immediate course correction possible.
+
+## Next steps
+
+- Tackle complex tasks with [Plan Mode](./plan-mode.md).
+- Build custom [Agent Skills](./skills.md).

docs/cli/plan-mode.md

@@ -107,7 +107,9 @@ structure, and consultation level are proportional to the task's complexity:
 4.  **Review & Approval:** Use the [`exit_plan_mode`] tool to present the plan
     and formally request approval.
     - **Approve:** Exit Plan Mode and start implementation.
-    - **Iterate:** Provide feedback to refine the plan.
+    - **Iterate:** Provide feedback to refine the plan. You can also use
+      [**model steering**](./model-steering.md) to provide real-time feedback
+      while Gemini CLI is researching or drafting the plan.
     - **Refine manually:** Press **Ctrl + X** to open the plan file in your
       [preferred external editor]. This allows you to manually refine the plan
       steps before approval. If you make any changes and save the file, the CLI

docs/sidebar.json

@@ -99,6 +99,11 @@
           { "label": "MCP servers", "slug": "docs/tools/mcp-server" },
           { "label": "Model routing", "slug": "docs/cli/model-routing" },
           { "label": "Model selection", "slug": "docs/cli/model" },
+          {
+            "label": "Model steering",
+            "badge": "🔬",
+            "slug": "docs/cli/model-steering"
+          },
           { "label": "Plan mode", "badge": "🔬", "slug": "docs/cli/plan-mode" },
           {
             "label": "Subagents",