A2A Documentation Index¶

🎯 Start Here¶

• 📖 A2A Overview - Start your learning journey here

📚 Learning Phases¶

Phase 1: Fundamentals 🔰¶

Core concepts you need to understand before anything else.

Start with: Core Concepts → Agent Identity

Phase 2: Discovery 🔍¶

How agents find and connect with each other.

Key concept: Agents advertise capabilities via cards, discoverable through registries

Phase 3: Security 🔐 ⭐ COMPREHENSIVE¶

Critical security concepts and implementations.

Learning Path: 1. Authentication Overview (understand the landscape) 2. Threat Model (know what you're defending against) 3. Code Walkthrough (see implementation evolution) 4. Authentication Tags (technical details)

Phase 4: Communication 💬¶

Message protocols and data exchange patterns.

Key patterns: Request/response, streaming, event-driven

Phase 5: Reference 📖¶

Technical reference materials.

💻 Code Examples with Security Analysis¶

Example 1: Vulnerable Implementation ❌¶

Location: ../../examples/a2a_crypto_example/
Security Rating: 0/10

Purpose: Educational - learn to identify vulnerabilities

What You'll Learn: - ❌ No input validation - ❌ No authentication - ❌ No rate limiting - ❌ No encryption - ❌ No audit logging

Use for: Learning what NOT to do, vulnerability identification practice

Example 2: Improved Implementation ⚠️¶

Location: ../../examples/a2a_crypto_simple_registry_example_1/
Security Rating: 4/10

Purpose: Educational - understand incremental improvements

What You'll Learn: - ✅ Basic input validation added - ✅ Simple signature verification - ✅ Service discovery (registry) - ⚠️ Still vulnerable to replay attacks - ⚠️ Weak cryptography - ⚠️ No rate limiting

Use for: Understanding security trade-offs, partial security pitfalls

Example 3: Production-Ready Implementation ✅¶

Location: ../../examples/a2a_crypto_example/security/
Security Rating: 9/10

Purpose: Production reference - template for secure implementations

What You'll Learn: - ✅ Comprehensive input validation (8 layers) - ✅ Strong cryptographic authentication (RSA/ECC) - ✅ Replay attack prevention (nonce-based) - ✅ Rate limiting (token bucket) - ✅ Structured audit logging - ✅ RBAC authorization - ✅ Defense-in-depth architecture

Use for: Production template, security pattern reference

🎓 Learning Paths¶

For Beginners (4-6 hours)¶

Goal: Understand A2A protocol and basic security

1. ✅ A2A Overview - Get the big picture (30 min)
2. ✅ Core Concepts - Learn fundamentals (45 min)
3. ✅ Agent Identity - Understand identity (30 min)
4. ✅ Agent Cards - Discovery mechanism (30 min)
5. ✅ Protocol Messages - Message structure (30 min)
6. ✅ Example 1 README - See basic implementation (1 hour)
7. ✅ Example 1 Security Analysis - Learn vulnerabilities (1 hour)

Outcome: Understand A2A basics and common security mistakes

For Security-Focused Developers (2-3 days)¶

Goal: Master secure A2A implementation

Day 1: Foundation & Threats 1. ✅ Authentication Overview - Trust models (2 hours) 2. ✅ Threat Model - Attack vectors (2 hours) 3. ✅ Example 1 Security Analysis - Vulnerability study (1 hour)

Day 2: Evolution & Patterns 4. ✅ Code Walkthrough Comparison - See progression (3 hours) 5. ✅ Example 2 Security Analysis - Incremental improvements (1 hour) 6. ✅ Authentication Tags - Technical details (1 hour)

Day 3: Production Implementation 7. ✅ Example 3 Security Analysis - Production patterns (2 hours) 8. 💻 Study Example 3 code - Implementation review (2 hours) 9. 🎯 Practice: Implement security module for your project (2+ hours)

Outcome: Able to implement production-grade secure A2A systems

For Protocol Implementers (1 week)¶

Goal: Build complete A2A implementation

Phase 1: Understanding (2 days) - All fundamentals documents - All discovery documents - All communication documents

Phase 2: Security Design (2 days) - All security documents - Compare all three examples - Design security architecture

Phase 3: Implementation (2 days) - Use Example 3 as template - Implement core protocol - Add security controls

Phase 4: Testing & Hardening (1 day) - Security testing - Performance testing - Documentation

Outcome: Complete, secure A2A implementation ready for production

For Security Auditors (Red Team) (1-2 days)¶

Goal: Audit A2A implementations for vulnerabilities

Phase 1: Reconnaissance 1. ✅ Threat Model - Know attack vectors (1 hour) 2. ✅ Authentication Overview - Understand defenses (1 hour)

Phase 2: Vulnerability Identification 3. 🔍 Audit Example 1 independently - Find flaws (2 hours) 4. ✅ Compare with Security Analysis 1 - Validate findings (30 min)

Phase 3: Bypass Techniques 5. 🔍 Attempt to exploit Example 2 - Test defenses (2 hours) 6. ✅ Compare with Security Analysis 2 - Learn bypasses (30 min)

Phase 4: Defense Review 7. 🔍 Test Example 3 defenses - Find weaknesses (3 hours) 8. ✅ Review Security Analysis 3 - Best practices (1 hour)

Outcome: Comprehensive security audit methodology for A2A systems

📊 Documentation Status¶

Completion Tracker¶

Recent Additions ✨¶

November 2025 - Security Documentation Sprint: - ✨ Authentication Overview - Trust models & authentication methods - ✨ Threat Model - STRIDE framework & 8 threats - ✨ Agent Identity - Identity fundamentals - ✨ Code Walkthrough Comparison - Side-by-side evolution - ✨ Security Analysis (Example 1) - Vulnerability breakdown - ✨ Security Analysis (Example 2) - Incremental improvements - ✨ Security Analysis (Example 3) - Production patterns

Impact: Security documentation now 80% complete with comprehensive coverage

🔗 Quick Links by Topic¶

Security Topics¶

• 🔐 Authentication
• 🎯 Threats
• 🛡️ Security Evolution
• 🏷️ Identity Tags

Protocol Topics¶

• 🆔 Agent Identity
• 📇 Agent Cards
• 📋 Registry
• 💬 Messages

Code Examples¶

• ❌ Example 1: Vulnerable
• ⚠️ Example 2: Improved
• ✅ Example 3: Secure

📖 Documentation Conventions¶

Status Indicators¶

• ✅ Complete - Fully written and reviewed
• 🟢 In Progress - Currently being written
• 📝 Planned - Outlined, not yet started
• ✨ New - Recently added

Difficulty Levels¶

• 🔰 Beginner - No prerequisites
• 📚 Intermediate - Requires fundamentals
• 🎓 Advanced - Requires security knowledge

Security Ratings¶

• ❌ 0-3/10 - Vulnerable
• ⚠️ 4-6/10 - Partially secure
• ✅ 7-10/10 - Production-ready

🎯 Navigation Tips¶

Linear Learning¶

Follow the phases in order: Fundamentals → Discovery → Security → Communication

Topic-Based Learning¶

Jump to specific topics using the quick links above

Problem-Based Learning¶

Start with a problem (e.g., "How do I prevent replay attacks?") and search the security docs

Example-Based Learning¶

Start with Example 1, understand issues, progress through Example 2 and 3

🔄 Keep Updated¶

This index is updated as new documentation is added. Check back regularly for: - New security topics - Additional examples - Advanced patterns - Case studies

Last Updated: November 2025
Next Update: Q1 2025 (Advanced security topics)

📬 Feedback¶

Found something unclear? Have suggestions? - Issues or questions → Contact project maintainer - Documentation gaps → Note in project issues - Success stories → Share your experience!

🚀 Ready to Start?¶

Beginners: Start → A2A Overview
Security Focus: Start → Threat Model
Implementers: Start → Example 3 README

Happy Learning! 🎓🔐

Legend: - ✅ Complete - 📝 Planned
- ✨ New - 🔰 Beginner - 📚 Intermediate - 🎓 Advanced - ❌ Vulnerable - ⚠️ Partially Secure - ✅ Secure