MCP servers

Declare a remote MCP server inline, right where you use it, with no separate config:

<Mcp id="linear" url="https://mcp.linear.app/mcp" only={["create_issue"]} />

id is the tool namespace (linear__create_issue) and the credential key. Placement is scope, like any tool: inside <GlobalTools> it is everywhere; inside a skill it is scoped to that skill. only is an optional allowlist of raw tool names. The server registers and connects on render; its tools appear once it is ready.

Credentials are implicit: never put a secret in agent code:

• Omit auth → a bearer token from MCP_<ID>_TOKEN in .env (id="linear" → MCP_LINEAR_TOKEN) if present, else OAuth: the server parks until you log in once via the preview’s “MCP servers” menu; tokens persist per-id in .mcp-auth/<id>.json (gitignored).
• Override with auth={{ kind: "bearer", token }} or auth={{ kind: "none" }}.

Alternatives: defineAgent({ mcpServers: [{ id, url, enabled }] }) pre-registers a server for eager connection before the first render; servers added at runtime through the preview persist in the project’s mcp.servers.json (tokens never land there).

Next steps

• Components: every prop of <Mcp>.