Remote MCP server URL: what it is and where to find it

A remote MCP server URL is the HTTPS address of a server's MCP endpoint: the single URL where an MCP client sends its requests, such as https://example.com/mcp. You get it from the server's docs or its administrator and paste it into your AI app's add-server or custom connector dialog. For Sume's hosted MCP server, the URL is https://mcp.sume.com/mcp.

The URL rules come from the MCP specification's Transports page (revision 2025-11-25) and MCP's guide to remote servers; where each client takes the URL comes from that client's own docs. All were read on 2026-09-28. Sume's side is from its MCP overview, MCP quickstart, and MCP OAuth and API keys.

What does a remote MCP server URL look like?

The spec requires a Streamable HTTP server to provide a single HTTP endpoint path, the MCP endpoint, that takes POST and GET requests; its example is https://example.com/mcp. MCP's guide asks for the complete URL, including the https:// protocol and any path components. The parts:

• https://, the scheme. A server on your own machine may use http://localhost, as in Android Studio's example http://localhost:1234/mcp, but that is a local server.
• The host: the server's domain, such as mcp.sume.com.
• The path, such as /mcp in the spec's example and in Sume's URL. A URL with /sse in it usually marks an endpoint for the older HTTP+SSE transport, which some clients configure in a different field.

Where do I find a server's MCP URL?

In the server's own docs, or from whoever runs it: MCP's guide says the URL should be provided by the server developer or administrator. Some clients also point to a registry; GitHub's Copilot CLI docs send you to the GitHub MCP Registry for the URLs of specific servers.

Where do I paste the URL?

Wherever your client asks for a remote or HTTP server. The fields differ; step by step for Claude is in Add Sume to Claude as a custom connector.

Is the URL all I need to connect?

Usually not. MCP's guide says most remote servers require authentication, commonly through OAuth or API keys, and the URL carries neither. With OAuth, the client finds where to sign in from the URL itself: Sume's quickstart says the client discovers protected-resource metadata from the MCP endpoint and sends you to https://mcp.sume.com/oauth/authorize, and the token is issued for the resource audience https://mcp.sume.com/mcp. With a Sume API key, the key goes in a header, Authorization: Bearer or x-api-key, not in the URL.

The URL must also be reachable from wherever the client runs. Claude's custom connectors connect from Anthropic's cloud, so the server must be reachable over the public internet; one on a private network or behind a VPN won't connect. Sume's sign-in steps are in Sume's MCP OAuth flow.

Can I open an MCP server URL in a browser?

Not usefully. It is an endpoint for JSON-RPC messages, not a web page. In current code, a GET to Sume's URL, which is what a browser sends, gets 401 and an OAuth challenge without a credential, and 405 with the message "Remote MCP uses POST JSON-RPC requests." with a valid one. To check that a URL works, connect a test client instead, as in how to test an MCP server.

What is Sume's remote MCP server URL?

https://mcp.sume.com/mcp, which Sume's docs say to use in Cursor, Claude Code, Codex, and other remote MCP clients. Sume has no official connector for any of them: each connects to it as a plain remote MCP server by this URL. OAuth sessions are read-only until you turn Write on at consent; API-key sessions see the full hosted tool set. Sume's basics page says hosted MCP still works but is not part of the primary path today.