THUDM releases slime: RL scaling post-training framework for LLMs
THUDM (Tsinghua University's Knowledge Engineering Group) has released slime, an open-source Python framework for LLM post-training via reinforcement learning scaling. The repository has accumulated 6,548 stars with 195 added in a single day, indicating significant community interest. RL-based post-training frameworks are a key area of active development following the success of techniques like GRPO and PPO in improving reasoning capabilities.
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ExpRL: RL-based mid-training using human QA data as reward scaffolds for LLM reasoning
ExpRL proposes an automated approach to LLM mid-training that replaces manually curated reasoning traces with large corpora of human-written QA data used as reward scaffolds rather than imitation targets. Reference solutions are hidden from the policy and used only to construct problem-specific grading rubrics, enabling dense process-level rewards that reinforce partial progress and intermediate reasoning steps. On challenging math reasoning benchmarks, ExpRL outperforms SFT, sparse-reward GRPO, and self-distillation as an RL initialization strategy, with additional mixed-domain experiments suggesting broader applicability.
TRL v1.0: Post-Training Library Built to Move with the Field
Hugging Face has released TRL v1.0, a major milestone for its post-training library focused on reinforcement learning from human feedback and related alignment techniques. The release signals a stabilization of the API and feature set after iterative development tracking the rapidly evolving post-training landscape. TRL is widely used in the open-source community for fine-tuning and aligning language models using methods such as PPO, DPO, and GRPO.
Make LLM Fine-tuning 2x faster with Unsloth and 🤗 TRL
Hugging Face published a blog post detailing an integration between Unsloth and TRL (Transformer Reinforcement Learning) library that claims to achieve 2x faster LLM fine-tuning. The post covers how Unsloth optimizes training kernels to reduce memory usage and increase throughput. This is relevant to practitioners looking to reduce compute costs and time for fine-tuning large language models.
StackLLaMA: A hands-on guide to train LLaMA with RLHF
Hugging Face published a detailed tutorial demonstrating how to fine-tune Meta's LLaMA model using Reinforcement Learning from Human Feedback (RLHF) on StackExchange data. The guide covers the full pipeline: supervised fine-tuning, reward model training, and PPO-based RL optimization. It serves as a practical reference for practitioners seeking to replicate RLHF workflows on open-weight models using the TRL library.
Learning to Reason with LLMs
OpenAI announced a new model or capability focused on reasoning in large language models, published on September 12, 2024. The post, hosted on the OpenAI blog, describes advances in training LLMs to perform complex multi-step reasoning. This likely corresponds to the release of the o1 (formerly 'Strawberry') model series, which uses chain-of-thought reasoning trained via reinforcement learning to achieve significantly improved performance on math, science, and coding benchmarks.
LongTraceRL: Reinforcement Learning for Long-Context Reasoning via Search Agent Trajectories and Rubric Rewards
LongTraceRL is a new RL training framework for improving long-context reasoning in LLMs, addressing limitations of existing RLVR methods. It constructs challenging training data using multi-hop questions from knowledge graph random walks and tiered distractors derived from search agent trajectories (high-confusability: read but uncited; low-confusability: seen but unopened). A rubric reward provides entity-level process supervision along reasoning chains, applied only to correct responses to prevent reward hacking. Experiments across three LLMs (4B–30B parameters) on five long-context benchmarks show consistent improvements over strong baselines.
Liger GRPO meets TRL: Efficient Reinforcement Learning Training Integration
The Hugging Face blog post announces the integration of Liger Kernel's GRPO (Group Relative Policy Optimization) implementation with TRL (Transformer Reinforcement Learning library). This combination aims to improve memory efficiency and training throughput for RL-based fine-tuning of language models. The integration targets practitioners running GRPO-style training on constrained hardware budgets.
PipelineRL: ServiceNow's Pipeline-Based Reinforcement Learning Framework for LLMs
ServiceNow introduces PipelineRL, a reinforcement learning training framework for large language models published via the Hugging Face blog. The post describes a pipeline-based approach to RL training, likely addressing throughput and efficiency challenges in RLHF or similar post-training workflows. As a tier-2 source with minimal body content, the technical depth is unclear but the topic is relevant to alignment and training infrastructure.