simlin

Run `npx skills add bpowers/simlin --all -g -y` in your terminal to install everything globally. You can also try the hosted version directly at simlin.com without installing anything.

Simlin is a system dynamics modeling tool for building stock-and-flow simulation models. It lets you simulate policies and strategies to test ideas faster and cheaper than real-world experiments.

Yes. Simlin reads and writes Vensim MDL files, XMILE (.stmx/.xmile), and its own JSON format, and can convert between them.

Yes. It ships an MCP server (@simlin/mcp) that lets AI assistants read, create, and edit models, plus Python bindings (pysimlin) for analysis in notebooks.

It uses the Loops That Matter method to show which feedback loops drive model behavior over time. Every model read returns ranked loops with polarity and importance scores.