Build a tool server any assistant can use

1. 01Write a server with two tools: lookup_parcel and list_claims

   The server runs as a child process and talks over standard input and output. Nothing listens on the network yet.

   npx @modelcontextprotocol/inspector uv run --with mcp server.py

   You pass when: The inspector opens and lists both tools with a description and typed arguments.

   Check step 1 server.py

2. 02Call lookup_parcel with an id that does not exist

   npx @modelcontextprotocol/inspector uv run --with mcp server.py

   You pass when: The tool returns a plain sentence saying the parcel was not found. No stack trace reaches the caller.

   Check step 2 server.py

3. 03Add the server to your coding agent and ask about a parcel

   claude mcp add parcel -- uv run --with mcp server.py && claude mcp list

   You pass when: The server is listed as connected, and the agent answers a parcel question by calling your tool. Other agents have their own add command.

   Check step 3

4. 04Serve the same tools over HTTP so a remote assistant can reach them

   Local process for tools on your machine, HTTP for tools shared by a team. Flisk scaffolds the second kind with flisk resource <name> --type mcp.

   npx @modelcontextprotocol/inspector

   You pass when: With the server started in HTTP mode, the inspector connects by URL and shows the same two tools.

   Check step 4 server.py

The check runs on the computer, not on your word: a step passes when its command exits with 0 there.