Connect Balatro Lab to MCP clients
Use a client supporting Streamable HTTP with JSON responses.
Initialize the connection, send the initialized notification, then list tools. Keep the negotiated MCP-Protocol-Version header on later requests. The service supports 2025-03-26, 2025-06-18 and 2025-11-25. GET /mcp returns 405; this endpoint is not a legacy SSE endpoint.
Remote endpoint
https://balatro.fantasysolvers.com/mcp
First prompt
Use Balatro Lab to inspect supported rules, then score 9H and 9S with Joker followed by The Duo, both standard edition. Report the actual tool result and its limitations.
Check the connection
Expect get_solver_capabilities, evaluate_hand, compare_actions and recommend_action. The score in the prompt is 336 at default levels with no held cards. Ask the assistant to show whether it actually invoked a tool; a guessed score is not a connection test.
Troubleshooting
Unsupported state: inspect the error path and capabilities; do not silently drop effects. Busy: at most two solver jobs run at once, so retry later. Timeout or budget exhaustion: no completed recommendation is available; reduce the supported state. Cannot connect: check account permissions, HTTPS, protocol version and Streamable HTTP transport.
Official client documentation · Complete API reference
Scope and trust
Supported model: 20 validated Jokers, 150 catalog names; exact analysis accepts 1–8 hand cards, 0–12 draw cards, 1–2 hands and 0–2 discards. Uniform replacement draws and optimal continuation are assumed. Unsupported boss, consumable, shop, history and scaling effects are rejected. No standalone sampled full-deck advice. Card order is optimized; Joker slot order is preserved.
Mathematical action values are conditional on the stated game model, not estimates of real-game success. Equal values are ties. Incomplete searches provide no completed recommendation. This independent tool is not affiliated with the game publisher.