Hey kentonv, this looks really neat. How would you go about writing API documentation for something like this? I really like writing up OpenAPI YAML documents for consumers of APIs I write so that any time someone asks a question, "How do I get XYZ?" I can just point them to e.g. the SwaggerUI. But I'm struggling to understand how that would work here.

For public-facing APIs, I would strongly recommend writing the TypeScript interfaces in a separate file from any implementation, and using JSDoc comments. There are various documentation generators that can turn that into a web page, though personally as a user I tend to prefer to just look at the actual TS file.