adornment-core

https://github.com/YaroslavZahoruiko/adornment-core

Adornment Core provides declarative method annotations for Ruby. Define annotation types, attach immutable metadata to the next method definition, and inspect annotations along Ruby's method lookup chain. Detects annotation declarations left without a method. Pure Ruby with no runtime dependencies. Does not wrap or replace methods. Supports CRuby 3.3 and later.