RLinf: A Friendly, End-to-End Guide to the New Open-Source Reinforcement-Learning Infrastructure
After reading this 3,000-word walkthrough you will know exactly what RLinf is, what it can do, how to install it, and why the team behind it believes it will become the default backbone for training intelligent agents.
1. Why We Needed Yet Another RL Framework
If you have ever tried training a robot arm, a large language model, or a game-playing agent with reinforcement learning, you have probably run into three headaches:
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Your graphics cards sit idle while the CPU is maxed out. -
Switching to a new model means rewriting the communication layer. -
Multi-node setups feel like black magic: one wrong port and the run dies at 3 a.m.
RLinf was created to remove those headaches. Its promise is simple: let researchers and engineers train large-scale reinforcement-learning systems as easily as writing a short Python script on a laptop.
2. What “RLinf” Actually Means
The letters “inf” stand for two things at once:
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Infrastructure – the solid ground on which everything else is built. -
Infinite – open-ended learning, continuous generalization, and no hard ceiling on model or data size.
3. Core Ideas Explained in Plain English
3.1 Macro-to-Micro Flow (M2Flow)
Term | Human Explanation | Practical Benefit |
---|---|---|
Macro flow | The high-level steps you write in Python: collect data → compute advantages → update policy. | You stay in familiar code. |
Micro flow | The low-level execution graph: which GPU samples data, which GPU updates weights. | The system optimizes this for you. |
Decoupling | The two layers are separated; change hardware without touching algorithm logic. | Less debugging, more iterating. |
3.2 Three Execution Modes
Mode | When to Use It | Main Advantage | Trade-Off |
---|---|---|---|
Collocated | Single machine, many GPUs | Shared GPU memory, low latency | Limited scaling |
Disaggregated | Multiple machines | Fine-grained pipelining, higher throughput | Needs fast interconnects |
Hybrid | In-between hardware setups | Pick and mix the above | Slightly more knobs to tune |
Good news: RLinf chooses the mode automatically based on workload and available resources.
3.3 Auto-Scheduling Strategy
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You keep writing Python. -
RLinf monitors GPU utilization, network bandwidth, and memory pressure. -
It flips the switch between Collocated, Disaggregated, or Hybrid, shaving off another 20–40 % of wall-clock time on average.
4. Built-In Support for Embodied Agents
Robotics and simulated agents are first-class citizens, not an afterthought.
Category | What You Get Out of the Box | Notes |
---|---|---|
VLA Models | OpenVLA, OpenVLA-OFT, π₀ | Load with one line of code. |
Simulators | ManiSkill3, LIBERO | CPU or GPU versions supported. |
Firsts | First-ever RL fine-tuning of the π₀ family | Tutorial already in the repo. |
5. Speed Claims Backed by Numbers
Metric | RLinf Hybrid | Other Frameworks | Gain |
---|---|---|---|
Throughput on identical hardware | 220 % | 100 % (baseline) | 120 %↑ |
Elastic scaling time | seconds | minutes | 20–40 % extra speed-up |
6. Ease of Use: Complexity Hidden, Simplicity Exposed
6.1 Multiple Backends
Backend | Best For | What Makes It Special |
---|---|---|
FSDP + Hugging Face | Beginners, quick prototypes | Zero-friction model loading |
Megatron + SGLang | Veterans, thousand-GPU jobs | 5-D parallelism baked in |
6.2 Algorithms Ready to Use
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PPO -
GRPO -
DAPO -
Reinforce++
Swap algorithms by changing one string—no rewrite needed.
7. Installation and First Steps
Official documentation: RLinf.readthedocs.io
7.1 One-Line Install
git clone https://github.com/RLinf/RLinf.git
cd RLinf
pip install -e .
7.2 Quickstart 1: Train a Robot Arm with PPO
# Tutorial: PPO Training of VLAs on Maniskill3
python examples/embodied/ppo_maniskill3.py
7.3 Quickstart 2: Train a Language Model with GRPO
# Tutorial: GRPO Training of LLMs on MATH
python examples/reasoning/grpo_math.py
8. Roadmap: What Will Arrive Next?
8.1 System-Level Enhancements
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[ ] Heterogeneous GPUs (e.g., A100 + RTX 4090 in the same job) -
[ ] Asynchronous pipeline execution -
[ ] Mixture-of-Experts (MoE) support -
[ ] vLLM inference backend
8.2 Application-Level Extensions
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[ ] Vision-Language Model training -
[ ] Deep-search agents -
[ ] Multi-agent environments -
[ ] More simulators: Meta-World, GENESIS -
[ ] More VLA models: NVIDIA GR00T -
[ ] World-model training -
[ ] Real-world RL beyond simulation
9. FAQ – Questions You Might Already Have
Q1: How is RLinf different from VeRL or DeepSpeed-Chat?
A: VeRL targets large language models; DeepSpeed-Chat focuses on dialogue fine-tuning. RLinf covers LLMs, VLMs, and VLA models, with robotics treated as a first-class workload.
Q2: I only have a single RTX 3090. Is RLinf overkill?
A: Not at all. Collocated mode is designed for single-machine, multi-GPU setups. The auto-scheduler will keep the 3090 busy without manual tuning.
Q3: How much code must I change to move from PPO to DAPO?
A: One line. Algorithms share the same interface; you only swap the algorithm name.
Q4: How painful is multi-node setup?
A: Follow the Multi-node Training guide—copy-paste the example host file and you are done.
Q5: Can I use LoRA for parameter-efficient fine-tuning?
A: Yes. The LoRA Integration page has step-by-step instructions.
10. Advanced Use Cases
Feature | Tutorial Link | One-Sentence Takeaway |
---|---|---|
5-D Parallelism | Guide | Megatron-level scaling for the largest models. |
Checkpoint Recovery | Guide | Interrupted run? Resume in seconds, not hours. |
11. Extending RLinf
12. Contribution Guidelines
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Read the contribution guide. -
Open an issue to discuss your idea. -
Submit a pull request; the CI pipeline will run end-to-end tests automatically.
13. Citation and Acknowledgement
If RLinf helps your research or product, please cite:
@misc{RLinf_repo,
title = {RLinf: Reinforcement Learning Infrastructure for Agentic AI},
howpublished = {\url{https://github.com/RLinf/RLinf}},
note = {GitHub repository},
year = {2025}
}
A full paper describing RLinf will be released on September 20, 2025. The repository will be updated with the official BibTeX entry when it becomes available.
14. Final Thoughts
RLinf is not “yet another framework.” It is an attempt to make large-scale reinforcement learning as boring as possible: you write the logic, the system handles the rest. Whether you are fine-tuning a language model to solve math problems or teaching a robot to fold laundry, RLinf offers a single, coherent path from a laptop prototype to a thousand-GPU cluster.
Your next step is simple: open a terminal, run git clone
, and let RLinf turn your next idea into reality.