Fine-tune LLMs using reinforcement learning with TRL - SFT for instruction tuning, DPO for preference alignment, PPO/GRPO for reward optimization, and reward model training. Use when need RLHF, align model with preferences, or train from human feedback. Works with HuggingFace Transformers.
Fine-tune LLMs using reinforcement learning with TRL - SFT for instruction tuning, DPO for preference alignment, PPO/GRPO for reward optimization, and reward model training. Use when need RLHF, align model with preferences, or train from human feedback. Works with HuggingFace Transformers.
version
1.0.0
author
Orchestra Research
license
MIT
tags
["DPO","Fine-Tuning","GRPO","HuggingFace","PPO","Post-Training","Preference Alignment","RLHF","Reinforcement Learning","SFT","TRL","agents","algorithms","artificial intelligence","automation","chatbots","cognitive services","deep learning","embeddings","frameworks","generative ai","inference","large language models","llm","machine learning","model fine-tuning","model finetuning","natural language processing","neural networks","nlp","openai","prompt engineering","rag","retrieval augmented generation","tools","vector databases","workflow automation"]
defreward_function(completions, **kwargs):
"""
Compute rewards for completions.
Args:
completions: List of generated texts
Returns:
List of reward scores (floats)
"""
rewards = []
for completion in completions:
# Example: reward based on length and unique words
score = len(completion.split()) # Favor longer responses
score += len(set(completion.lower().split())) # Reward unique words
rewards.append(score)
return rewards
Or use a reward model:
from transformers import pipeline
reward_model = pipeline("text-classification", model="reward-model-path")
defreward_from_model(completions, prompts, **kwargs):
# Combine prompt + completion
full_texts = [p + c for p, c inzip(prompts, completions)]
# Get reward scores
results = reward_model(full_texts)
return [r["score"] for r in results]
Step 2: Configure GRPO
from trl import GRPOConfig
config = GRPOConfig(
output_dir="Qwen2-GRPO",
per_device_train_batch_size=4,
num_train_epochs=1,
learning_rate=1e-5,
num_generations=4, # Generate 4 completions per prompt
max_new_tokens=128
)
Step 3: Train with GRPOTrainer
from datasets import load_dataset
from trl import GRPOTrainer
# Load prompt-only dataset
dataset = load_dataset("trl-lib/tldr", split="train")
trainer = GRPOTrainer(
model="Qwen/Qwen2-0.5B-Instruct",
reward_funcs=reward_function, # Your reward function
args=config,
train_dataset=dataset
)
trainer.train()