Each pipeline stage has a default AI Task Agent that handles it automatically. You can replace any of them with a custom agent — one you've installed from the Yao Agents Hub or built yourself. ## When to replace a stage agent The defaults work well for most Robots. Replace a stage agent when: - The default agent doesn't fit the Robot's specific domain (e.g. you want a specialized research agent for the Inspiration stage) - You've built a custom agent that formats output in a specific way the Delivery stage should use - You want to inject domain-specific validation logic in the Validation stage - You're fine-tuning a high-volume Robot and want tighter control over each step You don't need to replace every stage — replace only the ones where the default behavior isn't what you need. ## How to replace a stage agent Open the Robot in **Mission Control**, go to **Settings → Advanced**, and scroll to the **Execution Pipeline** section. Each stage has a dropdown — set to "Use global default" by default.  1. Click the dropdown for the stage you want to customize 2. Select a replacement agent from the list 3. Click **Save Changes** The custom agent takes effect on the next run. > 💡 Not sure which agent to use? Check the Yao Agents Hub for community-built stage agents, or ask the General Assistant to help you evaluate options. ## Reverting to the default To go back to the default agent for a stage: 1. Open the Robot's **Identity** tab 2. Click the customized stage 3. Select **Default** from the agent list 4. Save ## Constraints - A custom agent must declare itself compatible with the pipeline stage role it's replacing. Incompatible agents won't appear in the selection list. - If a custom agent is deleted from your hub, the stage falls back to the default automatically on the next run. ## What's next - [Pipeline Overview](/docs/en-us/mission-control/execution-pipeline/pipeline-overview) — understand what each stage does - [Yao Agents Hub](/docs/en-us/agent-hub/hub-overview) — find or install agents you can use as stage replacements - [Custom AI Experts](/docs/en-us/agent-hub/custom-assistants) — build your own agent to slot into a pipeline stage