> For the complete documentation index, see [llms.txt](https://docs.protoboard.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.protoboard.xyz/agent-bridge/overview.md).

# Overview

Connect Claude Code, Cursor, Codex or any MCP client to a board open in your browser and run the same tools ProtoBot runs

## Goal

Decide whether to drive Protoboard from your own AI agent, and know what to expect when you do.

The **Agent Bridge** is Protoboard's Model Context Protocol (MCP) server. It lets an external agent, such as Claude Code, Claude Desktop, Cursor, VS Code with Copilot or Codex, work on a board you have open in your browser. Your agent gets the same tools ProtoBot uses: search the library, place and wire parts, allocate pins, run DRC and manage the BOM.

## When to use it

* You work in a terminal or IDE and want board design in the same session as your code.
* You want a specific model or agent you already use.
* You want to script repetitive board work.

Use [ProtoBot](/protobot/overview.md) when you want zero setup, plan approval in the chat, and to watch the work in the app.

## How it works

1. You create an **agent API key** in **Settings > Developer**.
2. Your MCP client connects to `https://alpha.protoboard.ai/api/mcp` over Streamable HTTP and sends the key as `Authorization: Bearer pb_agent_…`. There's no OAuth sign-in.
3. Tool calls go to the board open in your browser and run there, so you see every change live. A green **AGENT** pill appears next to the board name; click it to see connected agents in **Agents > External**.

## Good to know

* **Keep the board open.** Board tools run in your browser tab. If the tab is asleep in the background, calls **queue** and run when you focus it; your agent can check them with `get_call_status`. Only a closed tab makes calls fail. Research tools (`search_web`, `fetch_url`, `search_docs`, `get_taxonomy`) work without a tab.
* **The connection is sticky.** With one board open, the agent connects to it automatically. Otherwise it uses `list_boards` and `connect_board`, and stays on that board until it calls `connect_board` again.
* **No board open?** `open_board` returns a link to a new or existing board. Your agent can open it for you if it can open URLs; otherwise open it yourself.
* **It acts as you.** The bridge reaches only boards you can access, and only board operations. It can't change billing, settings, sharing or keys.
* **Free on every plan.** Any account can create keys, and MCP calls don't use ProtoBot Energy.
* **Part requests file directly.** Unlike ProtoBot, an external agent's `submit_part_request` doesn't ask you first. Tell your agent if you want it to check with you.
* **Revoking is immediate.** Revoke a key in **Settings > Developer** and the next call fails.

## Next steps

* [Setup](/agent-bridge/setup.md): configure your client
* [Connect Claude Code through MCP](/tutorials/connect-claude-code.md): a five-minute walkthrough
* [Tool reference](/agent-bridge/tool-reference.md): every tool, whether it changes the board, and where it runs
* [Troubleshooting](/agent-bridge/troubleshooting.md)