coordinationcomplexemerging

A2A Protocol Pattern

Cross-vendor agent interoperability and standardized communication

Overview

The Challenge

Agents from different frameworks and vendors cannot reliably communicate or exchange capabilities, creating vendor lock-in and preventing cross-platform collaboration.

The Solution

Implement standardized agent-to-agent communication using the A2A Protocol, where agents advertise capabilities via Agent Cards, communicate via HTTP/JSON-RPC, and follow standardized task lifecycle states.

When to Use
  • Multi-vendor agent environments
  • Building agent marketplaces or platforms
  • Enterprise systems requiring interoperability
  • Cross-cloud agent orchestration
When NOT to Use
  • Single-vendor, closed ecosystems
  • Simple single-agent applications
  • When proprietary protocols provide critical features

Trade-offs

Advantages
  • +Vendor-agnostic interoperability
  • +Standardized capability discovery
  • +Enterprise-grade security built-in
  • +Supported by 100+ companies
Considerations
  • −Implementation overhead for simple use cases
  • −Standard still evolving
  • −Requires infrastructure investment
  • −May not support all proprietary features
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Deep Dive

Overview

The A2A (Agent-to-Agent) Protocol is an open standard for agent interoperability, backed by Google and 100+ enterprise partners including AWS, Microsoft, Salesforce, and SAP.

Key Components

Agent Cards

Standardized JSON documents that describe an agent's capabilities, endpoints, and authentication requirements. Published at .well-known/agent.json.

Communication Model

  • Client Agent: Initiates requests to remote agents
  • Remote Agent: Provides services and responds to requests
  • Task Lifecycle: Standardized states (pending, running, completed, failed)

Security

  • OAuth 2.0 / OpenID Connect authentication
  • Capability-based authorization
  • Rate limiting and quotas

Implementation

  1. Define your Agent Card with capabilities
  2. Implement the A2A server endpoints
  3. Register for capability discovery
  4. Handle task lifecycle events

References

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Considerations

A2A is an emerging standard - monitor for protocol updates and ensure backward compatibility.

PreviousConsensus-Based Decision Pattern
NextHandoff Pattern
Dimension Scores
Safety
4/5
Accuracy
4/5
Cost
3/5
Speed
3/5
Implementation
Complexitycomplex
Implementation Checklist
HTTP/JSON-RPC infrastructure
Agent Card schema
Authentication system
0/3 complete
Tags
interoperabilityprotocolstandardizationenterprisemulti-agent

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