@simlin/mcp

MCP (Model Context Protocol) server for Simlin, a system dynamics modeling tool. This server lets AI assistants read, create, and edit stock-and-flow simulation models.

Setup

Claude Code

claude mcp add simlin npx @simlin/mcp@latest

Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS, %APPDATA%\Claude\claude_desktop_config.json on Windows):

{
  "mcpServers": {
    "simlin": {
      "command": "npx",
      "args": ["@simlin/mcp@latest"]
    }
  }
}

Other MCP clients

Any MCP-compatible client can run the server over stdio:

npx @simlin/mcp@latest

Tools

| Tool | Description | |------|-------------| | ReadModel | Read a model file and return a JSON snapshot with loop dominance analysis | | EditModel | Apply operations (upsert/remove variables, name loops) to an existing model | | CreateModel | Create a new empty model file |

Supported file formats

| Format | Extensions | Read | Edit | |-------------------------|---------------------------|------|------| | XMILE | .stmx, .xmile, .xml | Yes | Yes | | JSON (Simlin and SD-AI) | .sd.json, .json | Yes | Yes | | Vensim | .mdl | Yes | No (import only) |

Skill resources

The PyPI package is pysimlin:

pip install pysimlin

Imported in Python as simlin:

import simlin

model = simlin.load("population.stmx")
run = model.run()
print(run.results["population"].iloc[-1])

The server also exposes skill resources around how to use the Python library:

• simlin://skills/pysimlin-basics -- Loading models, simulation, DataFrame access
• simlin://skills/scenario-analysis -- Parameter sweeps and intervention analysis
• simlin://skills/loop-dominance -- Feedback loop analysis and visualization
• simlin://skills/vensim-equation-syntax -- Vensim-to-XMILE function mapping

License

Apache-2.0