What problem does it solve? Setting up reinforcement learning post-training for large language models requires coordinating distributed training, high-throughput rollout generation, and data management, which is complex to configure correctly across frameworks. ## Core Features & Use Cases - GRPO and PPO Training: Run group-relative advantage estimation and other RL algorithms with Megatron-LM parallelism (TP, PP, DP, SP) and SGLang-based rollout. - Asynchronous and Multi-Turn Training: Overlap rollout and training for higher throughput, or train agents with tool use via custom generate functions. - Flexible Data Buffer: Manage prompts and rollout samples with custom filtering, off-policy buffering, and custom reward functions. - Use Case: Train a Qwen3-4B reasoning model on math problems by preparing JSONL prompt-label data, sourcing a pre-configured model script, and launching GRPO training with KL loss across 8 GPUs. ## Quick Start Ask the AI to set up a GRPO training run with slime for a Qwen3 model using your JSONL prompt dataset, including data preparation, model configuration, and launch commands.