---
title: 'Agents as MCP servers'
description: 'Connect Claude, Cursor or any MCP client to one of your agents and talk to it as a tool'
---
[View as Markdown](https://camelai.com/docs/camelrun/mcp-server.md) · [Docs index for coding agents](https://run.camelai.com/llms.txt)

Every agent is also an MCP server, at
`https://run.camelai.com/v1/agents/<agent id>/mcp` (Streamable HTTP).
Connect Claude, Cursor or any MCP client to it, and the model there can talk to
your agent. The server has one tool, `message`, which sends the agent a message
and returns its reply. The agent's own tools stay its own.

### Claude Code

```bash
claude mcp add --transport http support https://run.camelai.com/v1/agents/client_.../mcp
# Then run /mcp in Claude Code to sign in. Or skip signing in with a token from your environment:
claude mcp add --scope project --transport http support https://run.camelai.com/v1/agents/client_.../mcp \
  --header 'Authorization: Bearer ${SUPPORT_AGENT_TOKEN}'
```

The single quotes keep the variable as written, so the project's `.mcp.json`
names it and Claude Code reads its value from the environment. Never write a
token's value into an MCP config: they are often committed (see
[Keys stay out of MCP configs](/docs/camelrun/cli#keys-stay-out-of-mcp-configs)).

### Claude

In claude.ai or the desktop app, go to **Settings**, then **Connectors**,
then **Add custom connector**, and enter the agent's URL.

### Cursor and others

```json
{ "mcpServers": { "support": { "url": "https://run.camelai.com/v1/agents/client_.../mcp" } } }
```

The agent's id (`client_...`) is `agent.id` in the SDKs, and `GET /v1/agents`
lists every agent with its key.

## The `message` tool

| Argument    |                                                                                                                                 |
| ----------- | ------------------------------------------------------------------------------------------------------------------------------- |
| `text`      | The message to send                                                                                                             |
| `requestId` | Optional. Sending the same text with the same id again is the same message: it isn't sent twice, and the call returns its reply |

The tool's description tells the calling model what the agent is, so it knows
when to use it.

## How it behaves

* **One conversation.** A message joins the agent's history exactly as a
  prompt (`POST /v1/agents/{id}/prompt`) does, next to messages from the API,
  the console and channels. There are no separate threads per caller; to give
  each caller its own conversation, give each one its own agent. Each message is
  a run, limited and billed like any prompt.
* **Long turns.** A call lasts as long as the turn. It sends progress
  notifications while the agent works (its text as it streams, each tool it uses,
  and a heartbeat every 20 seconds), so clients that reset their timeout on
  progress keep waiting. A caller that goes away doesn't stop the turn.
* **Retries.** Pass `requestId` to make a retry safe. A call your client sends
  again in the same session is recognized without one.
* **A busy agent.** A message to an agent that is working queues behind its
  current turn, as a prompt does. Once 32 requests are open, the call fails with
  `The agent is busy: ...`.
* **Errors.** A failed run, a spend limit, a model error or a refused request
  comes back as a tool error carrying camelRun's message.

## Human input

When the turn [waits on a person](/docs/camelrun/human-input) and the client supports
MCP elicitation, the question, approval, form or page comes up in the client,
and the answer resumes the turn.

Otherwise the call ends with a result listing what the agent waits on
(`structuredContent.status` is `input_required`) and how to answer it. Once it's
answered, calling again with the same text and `requestId` returns the reply. A
new message instead sets the waiting inputs aside.

## Who may call it

Anyone who may prompt the agent: the agent's own token (the `token` it was
created with), an API key of your account, or an OAuth sign-in. A `401` names the
agent's protected-resource metadata, so clients sign in the same way as with the
[hosted MCP server](/docs/camelrun/cli#connect-your-coding-agent). Other accounts' tokens get
a `404`.

> **Warning:**
>
> Anyone you give the agent's token or an API key to can message the agent and
> spend on its model calls. Set a [spend limit](/docs/camelrun/models-and-keys#spend-limits)
> on agents you share.