This is a pure-Ruby forward-chaining rule engine based on the classic Rete algorithm.
Ruby >= 2.7 and JRuby are supported. Rubinius should work but isn't actively supported.
There is no API documentation, as most of the library's interfaces are for internal use only and would not be safe to use directly.
Instead, follow the tutorial and stick to the constructs described in it.
Until there is a 1.0 release, all minor versions should be treated as potentially breaking.
Always test your rules extensively. There's always a chance of you finding a bug in the engine that is only triggered by a very specific rule configuration.
The Rete implementation in this library largely follows the outline presented in [Doorenbos, 1995].