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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. 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 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.

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Get the stable URL

Use the stable Streamable HTTP URL for ordinary client configuration:
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:
Choose Streamable HTTP unless the client explicitly requires the older SSE transport.

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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:

Create a token for an agent

Generate a scoped token, choose its binding, and store the plaintext shown once.
Do not put the token in source control, the MCP URL, a query parameter, or an agent prompt.

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Put the token in the MCP client

Configure one remote HTTP MCP server with these values: A client’s exact configuration shape varies, but the resulting connection must be equivalent to:
Use the client’s environment-variable or secret-reference syntax when available rather than storing the plaintext value in the file.
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.

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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.