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

# Connect an MCP client

> Place the stable Fused MCP URL and an agent token in your MCP client.

Connect an MCP client with two values from Fused:

* The stable Streamable HTTP URL returned by `mcp apply` or `mcp list`.
* An MCP execution token sent in the `Authorization` header.

The MCP client owns JSON-RPC initialization, protocol negotiation, sessions, and reconnection. You only configure its URL and authentication.

For services that need a user's OAuth consent, see [Handle provider OAuth](/docs/mcp/use-the-server/provider-oauth). It explains how a capable client advertises URL elicitation and presents the authentication link when an operation needs it.

For provider webhook notifications, use a client that supports the Engine's combined MCP `2026-07-28` surface. [Receive MCP events](/docs/mcp/receive-events) covers explicit event selection, `subscriptions/listen`, and retained payload reads. The older session-based tool handshake described below does not by itself enable that event surface.

## Get the stable URL

```bash theme={null}
fused-cli mcp list
```

Use the stable Streamable HTTP URL for ordinary client configuration:

```text theme={null}
https://<engine-host>/mcp/<mcp-id>
```

One MCP name keeps this URL across versions. Applying a version promotes it for new client connections without changing their configuration. A connection already in progress stays on the immutable version it initialized.

The CLI also displays a version-pinned URL. Use it only when one client must remain on an exact immutable version:

```text theme={null}
https://<engine-host>/mcp/<version-id>
```

Choose Streamable HTTP unless the client explicitly requires the older SSE transport.

## Get an agent token

The first successful `mcp apply` may print a full-access token once. It is suitable for initial testing if you stored it securely.

For a long-running agent, create a separate token with the operations and connected-user binding it needs:

<Card title="Create a token for an agent" icon="ticket" href="/docs/mcp/agent-tokens">
  Generate a scoped token, choose its binding, and store the plaintext shown once.
</Card>

Do not put the token in source control, the MCP URL, a query parameter, or an agent prompt.

## Put the token in the MCP client

Configure one remote HTTP MCP server with these values:

| Client field | Value                          |
| ------------ | ------------------------------ |
| Transport    | Streamable HTTP                |
| URL          | The stable `/mcp/<mcp-id>` URL |
| Header name  | `Authorization`                |
| Header value | `Bearer <MCP execution token>` |

A client's exact configuration shape varies, but the resulting connection must be equivalent to:

```json theme={null}
{
  "name": "support-agent",
  "transport": "http",
  "url": "https://<engine-host>/mcp/<mcp-id>",
  "headers": {
    "Authorization": "Bearer <MCP execution token>"
  }
}
```

Use the client's environment-variable or secret-reference syntax when available rather than storing the plaintext value in the file.

<Note>
  The JSON shows the values and header placement, not a universal MCP client format. Use your client's documented field names while preserving the URL and `Authorization` header exactly. Never substitute a Fused License Key, CLI API key, or provider credential.
</Note>

## Verify the connection

Save or reload the MCP client configuration. A successful connection should display:

* The MCP server's authored capability description.
* The `search_docs` and `execute` tools.

The agent never receives the execution token as a tool argument. The MCP client keeps it on the connection and performs the protocol handshake itself.

If authentication fails, confirm the header is exactly `Authorization: Bearer <token>` and that the token is still active. If the stable URL is unavailable, the promoted version may have been deactivated; explicitly apply the version you want to promote.