verl

library0.7.1pypypiunverified

verl is a reinforcement learning framework for large language models (LLMs) developed by Volcano Engine. It provides end-to-end RL training (e.g., PPO, GRPO) with distributed compute and vLLM integration. Current version 0.7.1, actively developed and released on PyPI.

llm-agents ai-ml workflow

pip install verl

github ↗package ↗

INSTALL

IMPORT

SIG · VERL

verl

llm-agentspythonv0.7.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

WorkerGroup

✓ from verl import WorkerGroup

Main entry point for creating a group of workers for distributed RL

create_offload_inference_engine

✓ from verl.utils import create_offload_inference_engine

Helper to create an inference engine with offloading support

Initialize a WorkerGroup with an offloaded inference engine and generate text.

from verl import WorkerGroup from verl.utils import create_offload_inference_engine model_path = "Qwen/Qwen2.5-0.5B-Instruct" worker_group = WorkerGroup( num_gpus_per_worker=1, model_path=model_path, inference_engine=create_offload_inference_engine() ) # Example: generate completions prompts = ["What is RL?"] outputs = worker_group.generate(prompts) print(outputs)

Debug

Known issues

breakingverl 0.7.x dropped support for Python 3.9 and below. Only Python >=3.10 is supported.

fix

Upgrade Python to 3.10 or higher.

affects: >=0.7.0

gotchaWorkerGroup.generate() returns a list of strings, not a dictionary. New users often expect a dict with keys like 'text' or 'response'.

fix

Access completions directly via list indexing.

affects: all

gotchaThe inference engine must be created via `create_offload_inference_engine()` (or similar) before constructing WorkerGroup. Passing a raw vLLM engine will cause silent errors.

fix

Always use the utility function provided by verl to create the engine.

affects: all

Upgrade

Version history

0.7.1latest on PyPI · released Mar 16, 2026

Audit

Dependencies

vllmrequiredverl depends on vLLM for fast LLM inference during RL training

torchrequiredPyTorch is required for model training and tensor operations

Agent activity

63 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/volcengine/verl ↗

packagehttps://pypi.org/project/verl/ ↗