Comment by cortesi

I have a tiny, relevant weekend project:

https://github.com/cortesi/agentsmd

This is a command-line tool that lets you generate your AGENTS.md and CLAUDE.md files from common sources. So, for instance, if you have Rust-specific guidance for models, you can define it once, and then automatically include it in any project that contains Rust based on the `lang()` language matcher.

This is one of those small tools I now use many times a day to maintain and update ubiquitous agents files. Maybe other folks will find it useful too.