Simplify Fine-Tuning LLM Agents with LlamaGym

Main Features and Benefits of LlamaGym

1. Agent Abstraction Class

The core of LlamaGym is a single agent abstraction class. This allows users to quickly experiment and iterate with agent prompts and hyperparameters. This abstraction class includes three main methods for system prompts, observation formatting, and action extraction.

Example: Implementing a BlackjackAgent Class

from llamagym import Agent

class BlackjackAgent(Agent):
    def get_system_prompt(self) -> str:
        return "You are an expert blackjack player."

    def format_observation(self, observation) -> str:
        return f"Your current total is {observation[0]}"

    def extract_action(self, response: str):
        return 0 if "stay" in response else 1

This class is tailored for a blackjack game agent. Users can define the agent’s role through system prompts, convert the game state into text via observation formatting, and extract appropriate actions from the model’s responses.

2. Easy Model and Tokenizer Setup

LlamaGym simplifies the process of setting up the base LLM and instantiating the agent. Users can easily load pre-trained models and tokenizers and create agents based on them.

Example: Setting up the Llama-2-7b Model

model = AutoModelForCausalLMWithValueHead.from_pretrained("Llama-2-7b").to(device)
tokenizer = AutoTokenizer.from_pretrained("Llama-2-7b")
agent = BlackjackAgent(model, tokenizer, device)

This process is similar to traditional LLM fine-tuning tasks. Users load the Llama-2-7b model and its tokenizer, then pass them to the agent class to create the agent. This allows users to easily run the agent in an RL environment.

3. Reinforcement Learning Loop

LlamaGym simplifies the process of writing a reinforcement learning loop. This loop allows the agent to interact with the environment, receive rewards, learn, and perform training at the end of each episode.

Example: Reinforcement Learning Loop in a Blackjack Environment

env = gym.make("Blackjack-v1")

for episode in trange(5000):
    observation, info = env.reset()
    done = False

    while not done:
        action = agent.act(observation) # Act based on observation
        observation, reward, terminated, truncated, info = env.step(action)
        agent.assign_reward(reward) # Assign reward to agent
        done = terminated or truncated

    train_stats = agent.terminate_episode() # Perform training at end of episode

This code shows the process of the agent interacting with the environment and learning through received rewards. The agent selects actions based on observations and learns from the rewards returned by the environment. Through this process, users can continually improve the agent’s performance.

Considerations When Using LlamaGym

• Hyperparameter Tuning: Convergence in reinforcement learning can be very challenging, necessitating the adjustment of hyperparameters.
• Supervised Learning: Performing a supervised learning phase on sampled trajectories before running RL can enhance model performance.
• Simplicity vs. Efficiency: LlamaGym prioritizes simplicity, which may result in lower computational efficiency compared to other tools.

1. Importance of Hyperparameter Tuning

Hyperparameters play a crucial role in reinforcement learning. They directly affect the agent’s learning speed and performance. Therefore, users must experiment to find the optimal hyperparameters. LlamaGym helps users easily conduct these experiments.

2. Combining Supervised Learning and Reinforcement Learning

Performing supervised learning on sampled trajectories before starting reinforcement learning can help the agent learn faster and more effectively. This reduces instability in the RL process and improves initial performance.

3. Balancing Simplicity and Efficiency

LlamaGym prioritizes simplicity to enhance user accessibility. However, this may result in lower computational efficiency compared to other advanced tools. Users should choose the appropriate tool based on their needs.

Conclusion

LlamaGym is an innovative tool that combines reinforcement learning and LLM agents, helping users to easily fine-tune and experiment with agents. This allows users to maximize the potential of LLMs in RL environments. Reinforcement learning can significantly enhance the performance of LLMs, and LlamaGym provides an excellent starting point for this.