MCP server fails with `spawn uvx ENOENT`: use the absolute uvx path

Symptom

A Python MCP server launched with "command": "uvx" never starts; the client reports spawn uvx ENOENT.

Environment and tested versions

Debian GNU/Linux 13 (trixie) x86_64, node 20.19.2, npm 11.21.1; uvx at /usr/local/bin/uvx; client PATH stripped of uv/uvx (mimics a GUI app PATH)

• @modelcontextprotocol/sdk (TypeScript) 1.32.2
• node 20.19.2
• uv/uvx 0.13.5
• mcp-server-time 2026.10.28

Client used in the test: Reproduced with the official MCP TypeScript SDK stdio client (StdioClientTransport) 1.32.2 as a stand-in for a desktop app (Claude Desktop, Cursor, etc.), which can't run on the Linux test box. Not tested in the desktop app itself.

Root cause

Desktop clients start servers with a minimal PATH that often lacks the dir uv was installed to (~/.local/bin, ~/.cargo/bin, /usr/local/bin).

Fix steps

1. Run which uvx in your terminal.
2. Put that absolute path in "command" (uvx is a native binary, so the absolute path alone is enough).
3. Restart the client.

Verification

Tested 31 Oct 2026 in a throwaway directory on a Linux box (fake credentials only). Before (A) and after the fix:

== A uvx      (command "uvx")
FAILED: ENOENT spawn uvx ENOENT
== B abs uvx  (command "/usr/local/bin/uvx", args ["mcp-server-time"])
CONNECTED tools: get_current_time,convert_time
CALL: {"timezone":"Europe/Paris","datetime":"2026-10-31T20:05:55+01:00",...}

Sources

• https://github.com/modelcontextprotocol/servers/issues/760