> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rerun.build/llms.txt
> Use this file to discover all available pages before exploring further.

# Connect a client

> Wire Claude Code, Codex, Cursor, a Rerun agent or any MCP client to your workspace.

The server URL is the same for everyone:

```
https://app.rerun.build/api/mcp/account
```

It is an HTTP MCP server. Every snippet below sends your key in an `Authorization` header. The app shows these same snippets with your real key already filled in, right after you create it, under the workspace pill then **API keys & MCP**.

<Info>
  Replace `rk_your_key` with the key you copied. See [Authentication](/api/authentication) if you do not have one yet.
</Info>

## Claude Code

```bash theme={"system"}
claude mcp add --transport http rerun https://app.rerun.build/api/mcp/account --header "Authorization: Bearer rk_your_key"
```

Then ask Claude Code what it can do with Rerun. It calls `tools/list` on its own and discovers the 45 tools.

## Codex

Codex reads the key from the environment each time it starts the server, so export it first.

```bash theme={"system"}
export RERUN_MCP_KEY="rk_your_key"
codex mcp add rerun --url https://app.rerun.build/api/mcp/account --bearer-token-env-var RERUN_MCP_KEY
```

<Note>
  This is the Codex CLI. The ChatGPT app only accepts OAuth connectors, so an API key gets you nowhere there.
</Note>

## Cursor

Add the server to `~/.cursor/mcp.json`:

```json ~/.cursor/mcp.json theme={"system"}
{
  "mcpServers": {
    "rerun": {
      "url": "https://app.rerun.build/api/mcp/account",
      "headers": {
        "Authorization": "Bearer rk_your_key"
      }
    }
  }
}
```

## A Rerun agent

You can give one of your own agents the same reach over the workspace as an outside client. Open the agent panel, go to the **MCP** tab, click **New**, and paste:

```json theme={"system"}
{
  "name": "rerun",
  "transport": "http",
  "url": "https://app.rerun.build/api/mcp/account",
  "headers": {
    "Authorization": "Bearer rk_your_key"
  }
}
```

<Warning>
  This lets that agent create, edit and delete every other agent of the workspace, including itself. Do it on purpose, and prefer a dedicated agent for it.
</Warning>

## Any other client

Point the client at the URL and add the header.

| Field      | Value                                     |
| ---------- | ----------------------------------------- |
| Server URL | `https://app.rerun.build/api/mcp/account` |
| Transport  | HTTP                                      |
| Header     | `Authorization: Bearer rk_your_key`       |

For a client that only speaks stdio, bridge it:

```bash theme={"system"}
npx -y mcp-remote https://app.rerun.build/api/mcp/account --header "Authorization: Bearer rk_your_key"
```

## Check the connection

The cheapest call that proves everything works is `tools/list`.

```bash theme={"system"}
curl -s https://app.rerun.build/api/mcp/account \
  -H "Authorization: Bearer rk_your_key" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'
```

A `401 Unauthorized` in plain text means the key is missing, malformed or revoked. Anything else comes back as JSON-RPC. See [Protocol](/api/protocol) for the full handshake.