Other clients

Cursor, the MCP Inspector and any client that speaks Streamable HTTP.

Any MCP client that supports the Streamable HTTP transport, with a protocol version from 2025-03-26 through 2025-11-25, can use the URL with no authentication.

Cursor#

Add the server to ~/.cursor/mcp.json to use it in every project, or to .cursor/mcp.json inside one project:

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mcp.json

{  "mcpServers": {    "notes": {      "url": "https://api.meslzy.com/relay/v1/mcp/ut_8Hq3Lm2Vx7Tc9Rb4Nw1Ks6Jd5Yf0Pg2E"    }  }}

WarningA .cursor/mcp.json inside a repository is easy to commit. Keep a personal URL in the file in your home folder.

MCP Inspector#

The MCP Inspector shows what a host sees. Run it, choose the Streamable HTTP transport, paste the URL and connect. Listing tools shows the app's tool list; running a tool sends a real call to the app.

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shell

npx @modelcontextprotocol/inspector

Any Streamable HTTP client#

Send each JSON-RPC message in its own POST to the URL, with Content-Type: application/json and Accept: application/json, text/event-stream.
Read the response by its Content-Type: a call the app runs answers as an SSE stream; refusals and every other method answer as JSON.
Send MCP-Protocol-Version with one of 2025-03-26, 2025-06-18, 2025-11-25.
Expect no session: Relay never sends Mcp-Session-Id, and answers GET and DELETE with 405.
Use the URL as it is. There is no OAuth, and the MCP endpoint never answers 401.

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curl

curl https://api.meslzy.com/relay/v1/mcp/ut_8Hq3Lm2Vx7Tc9Rb4Nw1Ks6Jd5Yf0Pg2E \  -H "Content-Type: application/json" \  -H "Accept: application/json, text/event-stream" \  -H "MCP-Protocol-Version: 2025-11-25" \  -d '{"jsonrpc":"2.0","id":2,"method":"tools/list"}'

Every method and answer is described in MCP endpoint.

Clients that only speak the old SSE transport#

Clients that support only the older HTTP with SSE transport, which opens a GET stream and posts to a second endpoint, cannot connect, because Relay answers GET with 405.