verl

Coordinate scalable RLHF training for large language models with PPO, GRPO, DAPO, or RLOO.

Updated Aug 27, 2026
One-click install
npx skills add https://github.com/tylertitsworth/skills --skill verl-tylertitsworth
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: verl
Source: https://github.com/tylertitsworth/skills/tree/main/verl
Command: npx skills add https://github.com/tylertitsworth/skills --skill verl-tylertitsworth

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Train RLHF LLMs at scale by coordinating rollout generation, policy updates, and reward signals in a unified framework.

Core Features & Use Cases

  • Supports PPO, GRPO, DAPO, RLOO, and REINFORCE++ with stable training loops.
  • Integrates vLLM/SGLang for fast rollout generation and FSDP or Megatron-LM for scalable training.
  • Includes an SFT trainer and end-to-end RLHF pipelines for production-grade experiments.
  • Provides multi-GPU scaling, reward-model integration, checkpointing, and monitoring via WandB.

Quick Start

Configure your training in a YAML file, point verl at your data, and run the trainer to start RLHF fine-tuning of your model.

Frequently Asked Questions about verl

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I scale RLHF training for large language models across multiple GPUs?

To scale RLHF, this framework coordinates rollout generation, policy updates, and reward signals using FSDP or Megatron-LM backends across multiple GPUs. You configure multi-GPU infrastructure and YAML schemas to run end-to-end distributed training.

What RL algorithms are supported for fine-tuning LLMs?

Supported RL algorithms for LLM fine-tuning include PPO, GRPO, DAPO, RLOO, and REINFORCE++. These operate within stable training loops alongside an SFT trainer for end-to-end production pipelines.

Does vLLM work with FSDP for rollout generation during RLHF?

Yes, vLLM works with FSDP for fast rollout generation during RLHF. The framework integrates vLLM or SGLang for inference rollouts and uses FSDP or Megatron-LM for scalable policy updates across multi-GPU setups.

How do I start end-to-end RLHF fine-tuning using a YAML configuration?

To start end-to-end RLHF fine-tuning, configure SFT pretraining, RL algorithms, and rollout settings in a YAML file. Point the trainer at your high-quality Parquet data and execute it on multi-GPU infrastructure.

Do I need multi-GPU infrastructure and specific data formats for large-scale RLHF?

Yes, large-scale RLHF requires multi-GPU infrastructure and high-quality data in Parquet format. You also need configuration schemas for SFT pretraining, RL algorithms, and rollout settings to execute end-to-end training workflows.