Ensure STS2_MCP.dll and .json are in the /mods/ directory and mods are enabled in game settings.

STS2MCP MCP — Use Cases, Install & Live Demo

Why use it

Key features

Real-time game state exposure via REST API and MCP server
Autonomous AI gameplay — let Claude play full runs of STS2
Beta co-op mode for collaborative AI-human gameplay
Cross-platform: Windows, Linux, and macOS
Simple mod installation: drop DLL into mods folder

Live Demo

What it looks like in practice

sts2mcp-2.replay ▶ ready

0/0

Install

Pick your client

~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "sts2mcp-2": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/Gennadiyev/STS2MCP"
      ]
    }
  }
}

Open Claude Desktop → Settings → Developer → Edit Config. Restart after saving.

~/.cursor/mcp.json · .cursor/mcp.json

{
  "mcpServers": {
    "sts2mcp-2": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/Gennadiyev/STS2MCP"
      ]
    }
  }
}

Cursor uses the same mcpServers schema as Claude Desktop. Project config wins over global.

VS Code → Cline → MCP Servers → Edit

{
  "mcpServers": {
    "sts2mcp-2": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/Gennadiyev/STS2MCP"
      ]
    }
  }
}

Click the MCP Servers icon in the Cline sidebar, then "Edit Configuration".

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "sts2mcp-2": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/Gennadiyev/STS2MCP"
      ]
    }
  }
}

Same shape as Claude Desktop. Restart Windsurf to pick up changes.

~/.continue/config.json

{
  "mcpServers": [
    {
      "name": "sts2mcp-2",
      "command": "TODO",
      "args": [
        "See README: https://github.com/Gennadiyev/STS2MCP"
      ]
    }
  ]
}

Continue uses an array of server objects rather than a map.

~/.config/zed/settings.json

{
  "context_servers": {
    "sts2mcp-2": {
      "command": {
        "path": "TODO",
        "args": [
          "See README: https://github.com/Gennadiyev/STS2MCP"
        ]
      }
    }
  }
}

Add to context_servers. Zed hot-reloads on save.

claude mcp add sts2mcp-2 -- TODO 'See README: https://github.com/Gennadiyev/STS2MCP'

One-liner. Verify with claude mcp list. Remove with claude mcp remove.

Use Cases

Real-world ways to use STS2MCP

How to have Claude play a run of Slay the Spire 2

👤 STS2 players curious about AI strategy ⏱ ~60 min beginner

When to use: You want to see how an AI approaches deck building and combat decisions.

Prerequisites

STS2 with the mod installed — Download STS2_MCP.dll and .json to <game>/mods/, enable mods in settings
MCP server running — Server auto-starts on localhost:15526 when mod loads

Flow

Start a run

Start a new Slay the Spire 2 run. Check the game state — what character are we playing and what's our starting deck?✓ Copied

→ Character info, starting deck, and current map
Make strategic decisions

We're at a card reward screen. Analyze the options based on our current deck and suggest the best pick.✓ Copied

→ Analysis of each option with recommendation
Handle combat

We're in combat. Show me our hand, the enemies, and their intents. What's the optimal play order?✓ Copied

→ Combat analysis with recommended card play sequence

Outcome: A complete STS2 run with AI making strategic decisions.

Pitfalls

AI makes suboptimal decisions without full game knowledge — Provide context about game mechanics and synergies the AI may not know

Combinations

Pair with other MCPs for X10 leverage

sts2mcp-2 + filesystem

Log game states and decisions for analysis and strategy improvement

Log every decision point and our choice to ~/sts2/run-log.json for later analysis.✓ Copied

Tools

What this MCP exposes

Tool	Inputs	When to call	Cost
get_game_state	none	Get the current game state (map, deck, health, combat, etc.)	0
execute_action	action: str, params?: obj	Execute a game action (play card, end turn, make a choice)	0

Cost & Limits

What this costs to run

API quota: N/A — fully local
Tokens per call: 200–1000 tokens per game state query
Monetary: Free mod — requires Slay the Spire 2 ($24.99)
Tip: Query game state only at decision points, not every frame.

Security

Permissions, secrets, blast radius

Credential storage: N/A

Data egress: Local only — REST API on localhost:15526

Troubleshooting

Common errors and fixes

Mod not loading

Ensure STS2_MCP.dll and .json are in the <game>/mods/ directory and mods are enabled in game settings.

Verify: Check the game's mod manager for STS2MCP

Can't connect to API

The server starts on localhost:15526 when the mod loads. Ensure the game is running with the mod enabled.

Verify: curl http://localhost:15526/state

Game state returns empty during loading screens

Wait until the game finishes loading. State is only available during active gameplay.

Verify: Try again after the map or combat screen is visible

Alternatives

STS2MCP vs others

Alternative	When to use it instead	Tradeoff
Minecraft MCP Server	You want AI-controlled gameplay in Minecraft rather than a card game	Different genre — open world building vs strategic card game

More

Resources

📖 Read the official README on GitHub

🐙 Browse open issues

🔍 Browse all 400+ MCP servers and Skills