A2A CLI

A command-line client for the A2A (Agent-to-Agent) Protocol v0.3.0.

Overview

A2A CLI provides a rich, interactive command-line interface for interacting with A2A protocol servers. It allows you to connect to A2A-compatible agents, send tasks, monitor their progress, and view results in real-time.

Features

• A2A Protocol v0.3.0 Compliant - Full support for the latest specification
• Interactive chat mode with server agents
• Command-line interface for task management
• Multiple transport protocols (HTTP, SSE, WebSockets, STDIO)
• Agent discovery via /.well-known/agent-card.json
• Rich text UI with streaming responses
• Support for all A2A protocol methods
• Configuration management for multiple servers
• Session persistence and conversation memory

Installation

# Install from PyPI
pip install a2a-cli

# Or install from source
git clone https://github.com/chrishayuk/a2a-cli.git
cd a2a-cli
pip install -e .

Quick Start

# Start in interactive chat mode
uvx a2a-cli chat

# Send a task to a server
uvx a2a-cli --server http://localhost:8000 send "Hello, agent"

# Watch a task's progress
uvx a2a-cli watch <task-id>

Chat Mode

The interactive chat mode provides a rich interface for interacting with A2A agents:

uvx a2a-cli chat

In chat mode, you can:

• Type messages directly to communicate with the agent
• Use slash commands to perform specific actions
• View agent responses with rich formatting
• Monitor task status and artifacts in real-time

Common Chat Commands

Command Line Mode

A2A CLI can also be used as a traditional command-line tool:

# Send a task and wait for the result
uvx a2a-cli send "Generate a list of 5 movie recommendations" --wait

# Get details about a specific task
uvx a2a-cli get <task-id>

# Cancel a running task
uvx a2a-cli cancel <task-id>

Configuration

A2A CLI supports configuration files to manage multiple server connections. Create a file at ~/.a2a/config.json:

{
  "servers": {
    "local": "http://localhost:8000",
    "dev": "https://dev-agent.example.com",
    "prod": "https://agent.example.com"
  }
}

Then use them by name:

uvx a2a-cli --server local chat 

Or in chat mode:

/connect local

Transport Types

A2A CLI supports multiple transport protocols:

• HTTP: Standard JSON-RPC over HTTP
• SSE: Server-Sent Events for streaming responses
• WebSocket: Bidirectional communication
• STDIO: Standard input/output for CLI-based agents

Development

Requirements

• Python 3.11+
• Dependencies: a2a-json-rpc, httpx, rich, typer, prompt-toolkit

Setup

# Clone the repository
git clone https://github.com/yourusername/a2a-cli.git
cd a2a-cli

# Install in development mode
make dev-install

# Run tests
make test

Project Structure

a2a-cli/
├── src/
│   └── a2a_cli/
│       ├── a2a_client.py   # Main client class
│       ├── cli.py          # CLI entry point
│       ├── transport/      # Transport implementations
│       ├── chat/           # Chat interface
│       └── ui/             # UI components
├── tests/                  # Test suite
├── pyproject.toml          # Project metadata and dependencies
└── README.md               # This file

License

MIT