The ultimate guide to multi-harness RL

Hi folks, it's Lewis here from the post-training team at Hugging Face. We've been exploring how to train open models in different coding harnesses and wrote up a looong guide on how we solved this using open source libraries like TRL and the Harbor framework for RL environments. We hope you find this interesting, especially since everyone nowadays has their own custom harness (e.g. Pi + extensions) and now there's a recipe on how to squeeze the best performance on them with whatever open model you use as your daily driver. Happy to hear any comments or feedback!

Link to the guide: https://huggingface.co/spaces/FineEnvs/multi-harness-rl