Back in 2018, I wrote lethain/systemsas a domain-specific language for writing runnable systems models,and introduced it with this blog post modeling a hiring funnel.While it’s far from a perfect system, I’ve gotten a lot of value out of it over the last seven years,because it allows me to maintain systems models in version control.

As I’ve been playing with writing Model Context Protocol (MCP) servers,one I’ve been thinking about frequently is one to help writing systems syntax, and I fina...