Show HN: I built a MCP server so Claude can play Minesweeper
28 comments
·March 20, 2025breckenedge
Yea Claude sucks at minesweeper (and many spatial reasoning tasks), but isn’t an idea of MCPs is that Claude should be able to ask an MCP what the next best move is rather than figuring it out itself? Like offload hard thinking/reasoning to purpose-built solvers because they are deterministic? Though I guess you’d expect a reasoning model to be able to come up with its own solvers on the fly, especially for well-known problems. Maybe having access to an MCP itself is confusing it?
dartos
MCP is analogous to REST.
It doesn’t define what behavior should be where in a given app, just how to communicate what that behavior is and how to invoke it.
breckenedge
RPC, not REST
prats226
This seems like intended usage? The server actually executes the moves and interacts with the environment, the core orchestration or reasoning is offloaded to claude?
fragmede
MCP generically connects Claude to an environment, so it can be used to connect Claude to minesweeper, and then also to connect it to a CSP solver. Or a calculator and a dictionary. Or your GitHub and a devbox. Or Unity and a 3d printer.
breckenedge
Curious, I’ve yet to see Claude effectively use Unity.
fragmede
That repo's only a week old, give it some time.
Did Mario not do it for you? https://youtu.be/dCC7QoV5a6E
tmitchel2
It feels nuts to me that there is a push away from strict APIs to conversational interfaces for products and then the actual technology itself under the hood is translating that into a strict set of API calls in order to understand something. Would it not be better to seek interoperability with fairly well scripted natural language handshake. I feel like MCP is built for understanding language and Syntax to a greater degree but not random tools and APIs.
_joel
Maybe tell it it's a champion Minesweeper player and that loss is not an option :)
cbm-vic-20
For the acroym-averse:
MCP = Model Context Protocol
https://modelcontextprotocol.io/
"MCP is an open protocol that standardizes how applications provide context to LLMs."
ericol
By just looking at the README from the repo (Would look more deeply into this later) you're replying with an image of the current status? If you expect Claude to interpret the image corretly may be you're asking for too much. Besides the image (Gotta say I didn't know you could fed Claude images in MCP that's incredible cool) I'd rather / also return some json payload that informs Claude which positions has "cleared" neighbor positions, and their value. E.g.:
{"loc": {"x": 4, "y": 3}, "neighbors": [{"loc": {"x": 4, "y": 4}, "value": 1}, ... ]}
I would report only on the positions that has cleared neighbors, and hope for the best. Good luck!
(Impressive work BTW, I think we haven't even started to see the possibilities of MCP and I love people being this imaginative)
ericol
An interesting exercise here would be to make the MCP server show the actual state in a window and return to Claude just the json payload with the status.
tonypan
Good idea! I've updated the game server so a human can watch the game in real-time. Updated the README with a screen recording: https://github.com/tonypan2/minesweeper-mcp-server
codegladiator
Ditch the image
use this format for board representation
``` { "game_state": { "board_size": { "width": 9, "height": 9 }, "mines_total": 10, "mines_flagged": 2, "game_status": "in_progress", // "in_progress", "won", "lost" "time_elapsed": 45, "difficulty": "beginner" // "beginner", "intermediate", "expert", "custom" }, "board": [ ["1", "?", "?", "2", "1", "1", "1", "1", "0"], ["1", "2", "?", "2", "?", "1", "1", "?", "0"], ["0", "1", "1", "2", "1", "1", "1", "1", "0"], ["0", "0", "0", "0", "0", "0", "0", "0", "0"], ["1", "1", "0", "0", "0", "0", "0", "0", "0"], ["?", "1", "0", "0", "0", "1", "1", "1", "0"], ["1", "1", "0", "0", "0", "1", "F", "1", "0"], ["0", "0", "0", "0", "0", "1", "1", "1", "0"], ["0", "0", "0", "0", "0", "0", "0", "0", "0"] ], "last_action": { "action_type": "reveal", "x": 3, "y": 2, "result": "revealed_number", "timestamp": 1710931245 } } ```
and this format for llm response generation
``` { "action": { "action_type": "reveal", // "reveal", "flag", "unflag", "chord" "x": 5, "y": 3, "confidence": 0.95, "reasoning": "This cell is surrounded by revealed cells with low numbers, making it a safe choice." }, "game_analysis": { "identified_safe_cells": [[5, 3], [2, 5]], "identified_mine_cells": [[6, 1], [8, 2]], "uncertain_cells": [[1, 1], [2, 2]], "strategy": "Targeting isolated revealed areas first to gain more information." } } ```
It should fix all your issues plus also make it cheaper to play
lopsidedgrin
Teach Claude how to play Solitaire or Candy Crush at work and we will have come full circle.
stared
Key things for debugging:
* What is the data format it gets? Does it unambiguously correspond to output (i.e. without mistaking rows for cols, or indexes starting at 0 or 1)?
* What is the prompt?
* Is the model allowed to think? (If it is just JSON response, I expect it to suck, as tokens are units of thinking.)
viraptor
One way to sanity check would be to ask it to reproduce the board with the new position marked to make sure the board model works as expected.
tonypan
I noticed that Claude often tries to click out of bounds even though in the prompt I tell it that the index is zero based.
helsinki
Maybe I’m misunderstanding, but how is the actual game board / UI being rendered? I only see a MCP protocol definition.
tonypan
The game server is another Node app I built: https://github.com/tonypan2/minesweeper-server.
rcarmo
MCP is the new agentic, it seems. Most MCP stuff I've seen seems over-engineered, but this one was actually fun to check out.
punkpeye
Awesome to see MCP related work surfacing on the front page of HN!
jakeprins
cool
Hi! I build an MCP server that allows clients to play Minesweeper. It turns out that Claude is not very good at it (makes obvious mistakes, hasn't won a single game on a 9x9 board after many attempts).
I am curious how I can prompt Claude to do better?