#2020th of 31 in Training and fine-tuning

slime

RL post-training framework connecting Megatron training with SGLang rollout

Stars
8.7k
License
Apache-2.0
Last commit
Oct 2026
Last release
Oct 2026
Language
Python
Stars, last 29 weeks+3,705
1 Apr 2026: 5,004 stars8 Apr 2026: 5,131 stars15 Apr 2026: 5,260 stars22 Apr 2026: 5,377 stars29 Apr 2026: 5,466 stars6 May 2026: 5,517 stars13 May 2026: 5,613 stars20 May 2026: 5,678 stars27 May 2026: 5,750 stars3 Jun 2026: 5,917 stars10 Jun 2026: 6,031 stars17 Jun 2026: 6,147 stars24 Jun 2026: 6,713 stars1 Jul 2026: 7,181 stars8 Jul 2026: 7,322 stars15 Jul 2026: 7,459 stars22 Jul 2026: 7,570 stars29 Jul 2026: 7,670 stars5 Aug 2026: 7,743 stars12 Aug 2026: 7,852 stars19 Aug 2026: 8,128 stars26 Aug 2026: 8,244 stars2 Sept 2026: 8,349 stars9 Sept 2026: 8,417 stars16 Sept 2026: 8,481 stars23 Sept 2026: 8,521 stars30 Sept 2026: 8,574 stars7 Oct 2026: 8,602 stars14 Oct 2026: 8,666 stars21 Oct 2026: 8,709 stars

5,004 on 1 Apr 20268,709 on 21 Oct 2026

From GitHub's daily star counts.

Checked on GitHub.

Overview

slime is a reinforcement-learning post-training framework for LLMs. It runs Megatron for training and SGLang for rollout generation, coordinated by Ray and a shared Data Buffer. Custom generate functions, reward functions, verifiers and environments plug in through documented interfaces. The README says it is the RL framework behind the GLM-4.5 through GLM-5.3 releases.

Who it is for: ML engineers running large-scale RL post-training of LLMs on GPU clusters

Strengths

  • Used for RL training of GLM-4.5 through GLM-5.3, per the README
  • Megatron args pass through directly; SGLang args use the --sglang- prefix
  • Custom generate and reward hooks cover multi-turn, tool-use and agentic rollouts
  • Supports fully async rollout, PD disaggregation, delta weight sync, external rollout engines

Weaknesses

  • Requires Megatron, SGLang and Ray together; setup is involved
  • No Dockerfile or compose file detected in the repository
  • Hardware, RAM and VRAM requirements are not stated in the README
  • Aimed at multi-GPU RL runs, not small single-machine fine-tuning

What it needs

  • GPU required
  • Docker
  • Needs Megatron-LM, SGLang, Ray
  • Models: GLM, Qwen3.8, Qwen3.6, Qwen3.5, Qwen3-Next

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