fischer³ A2A Protocol - Break First Security Learning!¶

Agent-to-Agent (A2A) Protocol Security¶

For Secure, standardized communication between AI agents

Get Started View Protocol Browse Examples

🎯 What is A2A Protocol?¶

The Agent-to-Agent (A2A) Protocol is a standardized communication framework that enables AI agents to discover, authenticate, and collaborate with each other securely. Think of it as the "HTTP for AI agents" - a common language that allows autonomous systems to work together.

Key Features¶

Security First

Built-in authentication, encryption, and validation patterns protect against common vulnerabilities.

Security Guide
Discovery & Registration

Agents can find each other dynamically using standardized capability matching and registry patterns.

Discovery
Message Protocols

Standardized message types (request, response, handshake, error) with comprehensive schemas.

Messages
Production Ready

Complete validation patterns, error handling, and real-world examples demonstrating secure implementations.

Examples

🎯 Project Purpose¶

This learning project provides a structured path for developers to understand:

Model Context Protocol (MCP) - Connecting AI agents to tools and resources
Agent2Agent Protocol (A2A) - Enabling multi-agent communication and orchestration
Security Concerns - Identifying vulnerabilities in protocol implementations
Secure Implementation - Building production-ready systems with proper security controls

What Makes This Different?¶

Unlike typical documentation, this project: - Shows vulnerable code first - Learn to recognize security anti-patterns - Explains the risks - Understand why vulnerabilities matter - Demonstrates fixes - See how to implement proper security controls - Provides context - In-depth articles explain complex security concepts - Multiple learning paths - Three complete example progressions covering different security domains

🚀 Quick Start¶

Get up and running with A2A Protocol in minutes:

# 1. Define your agent
agent_card = {
    "agent_id": "my-agent-001",
    "name": "MyAgent",
    "version": "1.0.0",
    "capabilities": ["price_query", "data_analysis"],
    "supported_protocols": ["A2A/1.0"]
}

# 2. Send a handshake
handshake_message = {
    "message_type": "handshake",
    "payload": {"agent_card": agent_card}
}

# 3. Start communicating!
request = {
    "message_type": "request",
    "payload": {
        "method": "get_price",
        "parameters": {"currency": "BTC"}
    }
}

View Full Quick Start

📚 Learning Paths¶

Choose your path based on your background and goals:

For Complete Beginners¶

Goal: Understand what A2A is and why it matters

A2A Overview - Start here!
Core Concepts - What is agent-to-agent communication?
Agent Cards - How agents identify themselves
Message Types - Basic message structure

Time: 2-3 hours

For Developers¶

Goal: Build secure A2A agents

A2A Overview - Get the big picture
Security Best Practices - Critical security patterns
Message Validation - 8-layer defense
Code Examples - Learn from working implementations

Time: 4-6 hours

For Security Professionals¶

Goal: Audit and secure agent systems

Threat Model - Attack vectors
Authentication Tags - Crypto verification
Code Walkthrough - Vulnerable vs Secure
Security Analysis - Real vulnerability breakdowns

Time: 6-8 hours

For Non-Technical Professionals¶

Goal: Understand AI collaboration without code

AI Collaboration Fundamentals - No code required
Security for Non-Technical Audiences - Understand risks
Non-Technical Overview - Complete guide

Time: 2 hours

🎓 Documentation Structure¶

Protocol Documentation¶

Complete A2A specification with examples and best practices.

Complete Documentation Index ← Browse all docs
Fundamentals
Discovery & Registration
Security
Communication
Reference

Practical Examples¶

Four complete implementations showing evolution from vulnerable to secure.

Crypto Price Agent
Stage 1: Vulnerable baseline
Stage 2: Registry + basic auth
Stage 3: Production security
Credit Report Agent
Stage 1: Vulnerable file handling
Stage 3: Production security
Stage 4: AI integration
Task Collaboration
Stage 1: 25+ vulnerabilities
Stage 3: SessionManager
Stage 5: Web framework
Adversarial Agent
Stage 1: 5 attacks succeed
Stage 2: Partial defenses
Stage 3: Automated quarantine

💡 Key Concepts¶

Agent Card¶

A standardized identity declaration containing agent metadata, capabilities, and supported protocols.

{
  "agent_id": "crypto-agent-001",
  "name": "CryptoPriceAgent",
  "version": "1.0.0",
  "capabilities": ["price_query", "streaming"],
  "supported_protocols": ["A2A/1.0"]
}

Learn More About Agent Cards

Message Types¶

Standardized messages for different interaction patterns:

HANDSHAKE - Initial connection and capability exchange
REQUEST - Ask an agent to perform an action
RESPONSE - Return results (success or error)
ERROR - Report problems
DISCOVER_AGENTS - Find agents by capability

View All Message Types

Security Layers¶

Defense-in-depth with 8 validation layers:

Size Validation
Format Validation
Schema Validation
Type Validation
Range Validation
Sanitization
Business Logic
Security (Auth & Authz)

Security Deep Dive

📊 Project Stats¶

📄 Documents: 19 comprehensive guides
💻 Code Examples: 3 complete implementations (13 total stages)
🔒 Security Focus: 75+ vulnerabilities documented
📖 Total Content: 500+ pages of documentation
✅ Status: Production-ready v1.0

🎯 Use Cases¶

Financial Services¶

Multi-agent trading systems
Risk assessment coordination
Fraud detection networks
Compliance monitoring

Healthcare¶

Medical record sharing between AI systems
Diagnostic collaboration
Treatment recommendation coordination
Privacy-preserving data analysis

Enterprise¶

Task automation and delegation
Knowledge base integration
Customer service orchestration
Data pipeline coordination

Research¶

Distributed computation
Experiment coordination
Data sharing between institutions
Collaborative analysis

🛠️ Implementation Support¶

Complete Examples¶

Each example includes multiple stages showing security evolution:

Cryptocurrency Price Agent - Stage 1: Demonstrates 15+ common vulnerabilities - Stage 2: Adds registry and basic authentication - Stage 3: Production-grade security

Credit Report Agent - Focuses on PII protection and file validation - Shows 8-layer validation pattern - Includes AI integration example

Task Collaboration System - Multi-agent coordination patterns - Session management deep dive - Distributed systems (Redis) - Web framework integration (Flask)

Security Analysis¶

Every example includes: - ✅ Complete vulnerability documentation - ✅ Attack demonstration code - ✅ Before/after comparisons - ✅ Security best practices - ✅ Testing strategies

Model Context Protocol (MCP)¶

The A2A Protocol works alongside MCP:

MCP: Agent-to-tool communication (accessing data, APIs, services)
A2A: Agent-to-agent communication (collaboration, delegation, coordination)

Learn About MCP Integration

🤝 Contributing¶

This is an open documentation project. Contributions are welcome!

Found a bug? Open an issue
Want to contribute? Submit a pull request
Have questions? Start a discussion
Found a security issue? Report responsibly to robert@fischer3.net

Ways to Contribute¶

Improve documentation clarity
Add new examples
Report security findings
Translate to other languages
Share your implementations

📝 License¶

This documentation is released under the MIT License.

📬 Contact¶

Project Maintainer: Robert Fischer
Email: robert@fischer3.net

Next Steps¶

Ready to dive in? Here's where to go:

Start Learning → Browse Examples → View Documentation Index →

Last Updated: December 2025
Version: 2.0
Status: Active Development