kaiser-data/kitsune-mcp

Let your agent test the MCP server it's building.
Edit a tool, reload("dev") , call it again. No client restart.
⭐ Saved you a restart? Star it on GitHub so others find it.
📖 Documentation · Hot-reload tutorial · Tools reference
One prompt: Claude finds the bug, fixes it, reloads, checks again. Real recording, 31 s.
## Why
Your agent edits an MCP tool, but the client still runs the old process. Someone has to restart it before the agent can test the fix.
With Kitsune, connect, call and reload are tools. The agent runs the whole loop itself:
python
connect("uvx --from . my-mcp-server", name="dev") # start your server
shapeshift("dev") # its tools appear in the client
call("summarize", arguments={"url": "https://example.com"})
# … the agent (or you) edits the tool …
reload("dev") # restart on fresh code, remount
call("summarize", arguments={"url": "https://example.com"}) # new code, same session
It also mounts any of 130,000+ servers from 7 registries mid-session, caged in Docker.
Try it: hot-reload tutorial · examples/demo-hot-reload/
## Install
Claude Code
bash
claude mcp add -s user kitsune -- uvx kitsune-mcp
Any other client (Claude Desktop, Cursor, Windsurf, Cline, Zed, …):
json
"mcpServers": {
"kitsune": { "command": "uvx", "args": ["kitsune-mcp"] }
Also on PyPI (pip install kitsune-mcp, then "command": "kitsune-mcp") and npm (npx kitsune-mcp, delegates to uvx).
Requirements: Python 3.12+ · uv · node/npx for npm-based servers · Docker optional, used to cage community servers.
## Three things it does
| | Loop | What you get |
| MCP REPL | connect → shapeshift → edit → reload → call | Iterate on your own server without restarting the client |
| Long-tail reach | search → shapeshift → call → shapeshift() | Use a server once without adding it to your config forever |
| Try before you trust | confirm=True + Docker cage + version pins | Run community npm/PyPI code contained, not as your user |
### Borrow a server you never configured
python
search("web scraping")
shapeshift("firecrawl", tools=["scrapeurl"]) # mount one tool, not the whole server
call("scrapeurl", arguments={"url": "https://example.com"})
shapeshift() # drop it, session stays up
### Try a community package, caged
python
search("pdf", registry="glama")
shapeshift("mcp-pdf-tools", confirm=True) # npm/PyPI run in hardened Docker when available
call("extracttext", arguments={"path": "report.pdf"})
shapeshift()
### Add credentials mid-session
python
auth("BRAVEAPIKEY", "sk-...") # saved to ~/.kitsune/.env, no restart
shapeshift("brave", tools=["bravewebsearch"])
Full live walkthrough: docs/demo-realtime.md.
## When to use it, when not to
| Use Kitsune when… | Skip it when… |
| You're building an MCP server and want an edit/reload loop | You only use 1–3 trusted servers (configure them natively) |
| A task needs a server that isn't in your config | Every turn hits the same server (keep it always-on) |
| You want to evaluate community MCP code without installing it for good | You want lower token use: the base cost is ~1,774 tokens/turn, and modern clients already defer tool schemas |
| Your MCP config is crowded (GATEWAY) | You need a sub-second first call (cold mount takes ~1–15 s) |