Arca

Arca is a remote MCP server: there is nothing to install. Its endpoint is https://mcp.arca.build, served over Streamable HTTP. In an assistant that accepts remote MCP servers (often under a setting named connectors, integrations or tools), add a new server and give it this URL; in a client configured by file, add it as a remote (HTTP) server with the same URL.

It also lists an endpoint on the older SSE transport https://mcp.arca.build. Clients that support remote servers generally still accept SSE endpoints, though the protocol now favours Streamable HTTP.

The registry entry declares an HTTP header for the connection: Authorization (required, secret). A secret header usually carries an API key or token issued by the service; clients that accept custom headers set it with the server's URL.

Derived from the registry entry, not tested here. What the server does, and on what terms, is set by its publisher; check its repository or website before giving it access to your accounts or files. How to add an MCP server to an assistant · Before you connect