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

# Use the Labelbox MCP server

> Connect the Labelbox MCP server to the same MCP client as Recursion, so one conversation can read your labeling projects and run your agents.

The Labelbox MCP server gives an AI assistant tools for your Labelbox workspace: it can inspect projects and their data, and summarize labeling progress and quality. It works with Recursion. Add it to the MCP client that already uses the [Recursion MCP endpoint](/recursion/ai-coding-agents), and one conversation can read your labeling work and start agent sessions on it.

```mermaid theme={"theme":"css-variables"}
flowchart TD
  client["Your MCP client"] -->|"browser sign-in"| labeling["Labelbox MCP"]
  client -->|"API key"| recursion["Recursion MCP"]
  labeling --> workspace["Your workspace"]
  recursion --> sessions["Agent sessions"]
```

| Server | What your client does with it | How it signs in |
| - | - | - |
| **Labelbox MCP server** | Reads projects, data, queues, progress, and quality. | You sign in to your Labelbox account in your browser and approve access. No API key. |
| **Recursion MCP endpoint** | Finds and runs Managed Agents operations, such as starting a session. | An API key. |

<Note>
  For the Labelbox MCP server, you need a Labelbox account with access to a workspace where external MCP access is available and allowed by an administrator, and an MCP client that supports Streamable HTTP with OAuth sign-in, such as Claude Code, Codex, or Cursor. For Recursion, you need an API key, and starting a session needs an [agent](/recursion/agents), an [environment](/recursion/environments), and the Developer or Admin role. See [Connect to the Recursion MCP](/recursion/ai-coding-agents) and [Sessions](/recursion/sessions).
</Note>

## Connect the Labelbox MCP server

Add this server address to your MCP client:

```text theme={"theme":"css-variables"}
https://api.labelbox.com/v1/agent-tools/mcp
```

<Tabs>
  <Tab title="Claude Code">
    ```bash theme={"theme":"css-variables"}
    claude mcp add --transport http --scope user labelbox https://api.labelbox.com/v1/agent-tools/mcp
    ```

    Start Claude Code, enter `/mcp`, select the server, and authenticate.
  </Tab>

  <Tab title="Codex">
    ```bash theme={"theme":"css-variables"}
    codex mcp add labelbox --url https://api.labelbox.com/v1/agent-tools/mcp
    ```

    If sign-in doesn't start by itself, run `codex mcp login labelbox`.
  </Tab>

  <Tab title="Cursor">
    Add the server to `~/.cursor/mcp.json`, next to any servers already there:

    ```json theme={"theme":"css-variables"}
    {
      "mcpServers": {
        "labelbox": {
          "url": "https://api.labelbox.com/v1/agent-tools/mcp"
        }
      }
    }
    ```

    Open Cursor's MCP controls, find the server, and start its sign-in.
  </Tab>
</Tabs>

Your browser opens. Sign in to your Labelbox account, choose the workspace this connection uses, review the requested access, and choose **Allow access**. Keep the client open until it reports the server as connected.

The connection works with the permissions your Labelbox account already has; approving it adds none. A connection may be read-only. Whether you can also allow project changes depends on the access your client requests and on what your workspace permits.

For Claude, ChatGPT, and other clients, the access options, and how to disconnect a client, see the [Labelbox MCP server guide](https://docs.labelbox.com/horizon/guides/labelbox-mcp).

## Check both connections

Start a new session in your client and ask:

```text theme={"theme":"css-variables"}
Use the Labelbox MCP server to show my connected workspace and access
restrictions. Then use the recursion MCP server to list my agents.
```

The first answer names the workspace you chose. The second lists the agents in your Recursion organization. If either is missing, see [What can go wrong](#what-can-go-wrong).

## Use them together

With both servers connected, your client can read from one and act in the other. For example:

```text theme={"theme":"css-variables"}
Use the Labelbox MCP server to summarize progress, throughput, and benchmarks
for project <project-id>, and show its queues. Then use the recursion MCP
server to start a session with my "Labeling review" agent in my "Default"
environment. Put the summary in its first message and ask it to draft a plan
for the queues that need attention.
```

Your client calls the Labelbox MCP server's tools first, then starts the session through the Recursion MCP endpoint. Open **Sessions** in the console to follow the agent's work. See [Sessions](/recursion/sessions).

Another prompt to try:

* "Which datasets and batches are attached to this project? Start a session that checks them against our data checklist."

What your client passes into a session is kept with that session's history. See [Data handling](/recursion/security#data-handling) before you send workspace content.

## Agents that run in Recursion

The Labelbox MCP server signs you in through your browser, so you connect it to your MCP client, as on this page. It isn't a server you add to an agent's own MCP servers: an agent that runs in Recursion reaches a server with a token stored in a vault. See [MCP servers](/recursion/mcp-servers).

To give such an agent context from your Labelbox workspace, have your client read it and pass it in the session's first message, as in the prompt above.

## What can go wrong

The most common problems:

* **No workspace is offered during sign-in.** You signed in to a different account, or the workspace doesn't allow external MCP connections. Ask a workspace administrator to allow them. If they're allowed and the workspace is still missing, contact support as the guide below describes.
* **The tools don't appear after you approve.** The client stopped waiting before authorization finished. Keep the client open, start its sign-in again, and check its MCP status.
* **A tool is missing or access is denied.** Your permissions are checked on every call, and a connection limited to selected projects offers fewer tools. Check your role and the access you approved, then connect again if you need more.
* **The Recursion tools don't appear, or calls return `401 unauthorized`.** The API key isn't set where the client started, or it expired. See [Connect to the Recursion MCP](/recursion/ai-coding-agents#what-can-go-wrong).

For every other connection problem with the Labelbox MCP server, see the troubleshooting section of the [Labelbox MCP server guide](https://docs.labelbox.com/horizon/guides/labelbox-mcp).

## Next steps

<CardGroup cols={2}>
  <Card title="Labelbox MCP server guide" href="https://docs.labelbox.com/horizon/guides/labelbox-mcp">
    Set up other clients, choose access options, and manage connections.
  </Card>

  <Card title="Connect to the Recursion MCP" href="/recursion/ai-coding-agents">
    Connect the docs server and the authenticated endpoint with an API key.
  </Card>

  <Card title="Sessions" href="/recursion/sessions">
    Start, steer, and follow the sessions your client creates.
  </Card>

  <Card title="MCP servers" href="/recursion/mcp-servers">
    Give an agent that runs in Recursion tools from a server that takes a token.
  </Card>
</CardGroup>