STS2 Agent

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STS2 AI Agent

 is a Slay the Spire 2 mod + MCP server bundle:

• STS2AIAgent : exposes game state and actions through a local HTTP API
• mcp_server : wraps that local API as an MCP server for AI clients

Quick Start

1. Install The Mod

After downloading and extracting the release package, copy these files into your game's mods/ directory:
STS2AIAgent.dllSTS2AIAgent.pck
mod_id.json

The default Steam install path is usually:
C:\Program Files (x86)\Steam\steamapps\common\Slay the Spire 2
Your final layout should look like this:
Slay the Spire 2/ mods/
STS2AIAgent.dll
STS2AIAgent.pck
mod_id.json

2. Start The Game And Confirm The Mod Is Loaded

Launch the game normally so the mod can load with it.
Then open:
http://127.0.0.1:8080/health
If the endpoint responds, the mod is running.

3. Start The MCP Server

Prepare the environment first:

1. Install Python 3.11+
2. Install uv

Install uv on Windows:
powershell -ExecutionPolicy Bypass -c "irm https://astral.sh/uv/install.ps1 | iex"
On macOS:
brew install uv

Then start the default stdio MCP server.

Windows:
powershell -ExecutionPolicy Bypass -File ".\scripts\start-mcp-stdio.ps1"
macOS / Linux:
./scripts/start-mcp-stdio.sh
This is the recommended default. Most desktop AI clients prefer stdio MCP integration.

4. Connect Your MCP Client

If your client supports command-based MCP startup, point its working directory at mcp_server/ and use:
uv run sts2-mcp-server

If your client works better over HTTP, start the network server instead.

Windows:
powershell -ExecutionPolicy Bypass -File ".\scripts\start-mcp-network.ps1"
macOS / Linux:
./scripts/start-mcp-network.sh
Default MCP endpoint:
http://127.0.0.1:8765/mcp