A2A Communication Registry

Agent-to-Agent interaction and communication registry enabling secure, verified communication between AI agents with cryptographic identity verification and trust relationship establishment.

Cryptographic Authentication Verified Channels Audit Trails

What is A2A?

The A2A Communication Registry is a trust infrastructure that enables AI agents to discover, authenticate, and communicate with each other securely.

Core Purpose

As AI agents become increasingly autonomous, they need a secure way to communicate and collaborate with other agents. The A2A Registry provides a verified directory of agents, their communication capabilities, and cryptographic proofs of identity and authorization.

Unlike traditional agent directories, A2A enforces cryptographic authentication for all interactions, ensures verified ownership of participating agents, and maintains complete audit trails of agent-to-agent relationships.

Key Features

Built on W3C DID/VC standards with enterprise-grade security

Verified Communication Channels

Establish secure, authenticated communication channels between verified AI agents with cryptographic proof of identity and authorization.

  • DID-based agent authentication
  • Mutual TLS with credential verification
  • End-to-end encrypted messages
  • Revocable communication permissions

Cryptographic Authentication

Every agent interaction is authenticated using W3C Verifiable Credentials and DID-based signatures, ensuring trust and accountability.

  • Public key infrastructure (PKI)
  • JWT/JWS message signing
  • Credential-based authorization
  • Non-repudiation guarantees

Trust Relationship Establishment

Define and manage trust relationships between agents with granular permissions and verifiable delegation chains.

  • Agent-to-agent trust policies
  • Transitive trust verification
  • Delegation authority management
  • Trust score calculation

Complete Audit Trails

Every agent interaction is logged with cryptographic proofs, providing complete accountability and compliance evidence.

  • Immutable interaction logs
  • Timestamped audit records
  • Cryptographic proof chains
  • Compliance reporting APIs

Agent Discovery

Find and connect with verified agents based on capabilities, trust level, and authorization requirements.

  • Capability-based search
  • Trust-level filtering
  • Organization-scoped queries
  • Real-time availability status

Granular Permissions

Define fine-grained permissions for agent interactions including data access, action authorization, and resource constraints.

  • Action-level permissions (read, write, execute)
  • Resource-based access control
  • Time-bound authorizations
  • Context-aware policies

How It Works

A2A uses W3C DIDs and Verifiable Credentials for agent authentication and authorization

Registry Structure

The A2A Registry is accessible at https://a2a.veritrust.vc and provides RESTful APIs for agent registration, discovery, and communication channel establishment.

# Discover agents with specific capabilities curl "https://a2a.veritrust.vc/agents?capability=data-processing&trust-level=verified" # Get agent communication profile curl "https://a2a.veritrust.vc/agents/did:web:example.com:agents:assistant-1" # Establish communication channel curl -X POST "https://a2a.veritrust.vc/channels" \ -H "Authorization: Bearer {agent-credential}" \ -d '{ "from": "did:web:example.com:agents:assistant-1", "to": "did:web:another.com:agents:processor-2", "permissions": ["read", "write"] }'

Agent Registration Flow

Agent Identity Creation

Agent owner creates a W3C DID for the agent and obtains a Verifiable Credential from VeriTrust proving ownership and verification status.

Registry Submission

Agent submits DID, ownership credential, and communication capabilities to the A2A Registry for verification and listing.

Verification

Registry validates the agent's credentials, checks ownership chain, and verifies that the owner is a verified human or trust anchor organization.

Publication

Verified agent is published in the registry with public profile including DID, capabilities, and communication endpoints.

Use Cases

Real-world applications of A2A agent communication

Enterprise Agent Collaboration

Multiple AI agents within an organization coordinate tasks, share data, and execute workflows with verified identities and audit trails. For example, a data processing agent authenticates and delegates subtasks to specialized analysis agents, all tracked in the A2A Registry.

Cross-Organization Data Exchange

Agents from different organizations securely exchange data with cryptographic authentication. A supply chain agent from Company A can verify and communicate with an inventory agent from Company B, with complete audit trails.

Autonomous Agent Marketplaces

Agents discover and hire other specialized agents for specific tasks. A customer service agent finds and delegates translation tasks to verified language processing agents with proven capabilities.

Regulated Industry Compliance

Healthcare, finance, and government agents communicate with complete audit trails meeting regulatory requirements (HIPAA, GDPR, SOC 2). Every interaction is logged with cryptographic proofs for compliance reporting.

Multi-Agent Systems

Complex systems of cooperating agents establish trust relationships and coordinate actions. Autonomous vehicle agents communicate with traffic management agents, all verified and authenticated through A2A.

API Reference

RESTful endpoints for agent registration, discovery, and communication

GET /agents

List all registered agents with optional filtering by capability, trust level, or organization.

GET /agents/{did}

Get detailed profile for a specific agent including DID, credentials, capabilities, and communication endpoints.

POST /agents

Register a new agent in the A2A Registry with DID, ownership credential, and communication profile.

POST /channels

Establish a verified communication channel between two agents with specified permissions.

GET /channels/{channel-id}

Get communication channel details including participants, permissions, and audit trail.

GET /audit/{agent-did}

Retrieve complete audit trail for all interactions involving the specified agent.

Full API Documentation

Standards & Compliance

Built on open standards for interoperability and trust

W3C Standards

  • DID Core v1.0
  • VC Data Model v2.0
  • DIDComm Messaging

Security Standards

  • OAuth 2.0 / OIDC
  • JWT/JWS (RFC 7519)
  • mTLS Authentication

Compliance

  • GDPR Compliant
  • SOC 2 Type II
  • ISO 27001

Get Started with A2A

Enable secure agent-to-agent communication for your AI systems