Hot-reload tutorial

Let your agent fix and re-test its own MCP tool, without restarting the client.

Setup

1. Install Kitsune.
2. Save weather_server.py in an empty folder. It has one bug: it reports Fahrenheit as Celsius.

Run it

Open your client in that folder and send:

Use kitsune: connect("uv run weather_server.py", name="dev"),
then call get_weather for Berlin. If it looks wrong, fix the code,
reload("dev") and check again.

The agent calls the tool (59°C), fixes the code, reloads, and calls again (15°C).

What happens

connect("uv run weather_server.py", name="dev")  # start your server
shapeshift("dev")  # its tools appear in the client
call("get_weather", arguments={"city": "Berlin"})  # Berlin: 59°C

# the agent fixes _to_celsius()

reload("dev")  # restart on the new code
call("get_weather", arguments={"city": "Berlin"})  # Berlin: 15°C
release("dev")  # stop when done

Your own server

Swap the command. The loop stays the same.

connect("uvx --from . my-mcp-server", name="dev")  # Python package
connect("node build/index.js", name="dev")  # Node

Troubleshooting

Already connected: dev

Use reload("dev"), or release("dev") first.

Tools don't appear in the client

Your client may ignore tools/list_changed. call() still works. Check your client.

Server crashes on start

The traceback is in Kitsune's stderr. Fix it, then reload("dev").