OpenHands/openhands/agenthub/codeact_agent/README.md

CodeAct Agent Framework

This folder is an implementation of OpenHands's main agent, the CodeAct Agent. It is based on (CodeAct, tweet), an idea of consolidating LLM agents' actions into a unified code action space for both simplicity and performance.

Overview

The CodeAct agent operates through a function calling interface. At each turn, the agent can:

1. Converse: Communicate with humans in natural language to ask for clarification, confirmation, etc.
2. CodeAct: Execute actions through a set of well-defined tools:
   • Execute Linux bash commands with execute_bash
   • Run Python code in an IPython environment with execute_ipython_cell
   • Interact with web browsers using browser and fetch
   • Edit files using str_replace_editor or edit_file

Built-in Tools

The agent provides several built-in tools:

1. execute_bash

• Execute any valid Linux bash command
• Handles long-running commands by running them in background with output redirection
• Supports interactive processes with STDIN input and process interruption
• Handles command timeouts with automatic retry in background mode

2. execute_ipython_cell

• Run Python code in an IPython environment
• Supports magic commands like %pip
• Variables are scoped to the IPython environment
• Requires defining variables and importing packages before use

3. web_read and browser

• web_read: Read and convert webpage content to markdown
• browser: Interact with webpages through Python code
• Supports common browser actions like navigation, clicking, form filling, scrolling
• Handles file uploads and drag-and-drop operations

4. str_replace_editor

• View, create and edit files through string replacement
• Persistent state across command calls
• File viewing with line numbers
• String replacement with exact matching
• Undo functionality for edits

5. edit_file (LLM-based)

• Edit files using LLM-based content generation
• Support for partial file edits with line ranges
• Handles large files by editing specific sections
• Append mode for adding content to files

Configuration

Tools can be enabled/disabled through configuration parameters:

• enable_browsing: Enable browser interaction tools
• enable_jupyter: Enable IPython code execution
• enable_llm_editor: Enable LLM-based file editing (falls back to string replacement editor if disabled)

Micro-agents

The agent includes specialized micro-agents for specific tasks:

1. npm: Handles npm package installation with non-interactive shell workarounds
2. github: Manages GitHub operations with API token support and PR creation guidelines
3. flarglebargle: Easter egg response handler

Adding New Tools

The CodeAct agent uses a function calling interface based on litellm's ChatCompletionToolParam. To add a new tool:

1. Define the tool in function_calling.py:

MyTool = ChatCompletionToolParam(
    type='function',
    function=ChatCompletionToolParamFunctionChunk(
        name='my_tool',
        description='Description of what the tool does and how to use it',
        parameters={
            'type': 'object',
            'properties': {
                'param1': {
                    'type': 'string',
                    'description': 'Description of parameter 1',
                },
                'param2': {
                    'type': 'integer',
                    'description': 'Description of parameter 2',
                },
            },
            'required': ['param1'],  # List required parameters here
        },
    ),
)

2. Add the tool to get_tools() in function_calling.py
3. Implement the corresponding action handler in the agent class

Implementation Details

The agent is implemented in two main files:

1. codeact_agent.py: Core agent implementation with:

   • Message history management
   • Tool execution handling
   • State management
   • Action/observation processing

2. function_calling.py: Tool definitions and function calling interface with:

   • Tool parameter specifications
   • Tool descriptions and examples
   • Function calling response parsing