A2A
Agent-to-Agent Protocol
Google's open protocol for AI agent interoperability. How agents from different platforms discover each other and collaborate — without speaking the same "language."
What is A2A?
If MCP is how agents talk to tools, A2A is how agents talk to each other. It lets an agent built on MeetLoyd collaborate with an agent built on LangChain, AutoGen, or any other platform — as long as both speak A2A.
A2A was created by Google, released as v1.0 RC in January 2026, and is supported by 50+ partners including Anthropic, Microsoft, Salesforce, SAP, and the Linux Foundation.
The Agent Card
Every A2A-compatible agent publishes a JSON file at /.well-known/agent.json — its "business card." This tells other agents: who I am, what I can do, and how to reach me.
{
"name": "Compliance Reviewer",
"description": "GDPR compliance analysis",
"url": "https://agents.acme.com/compliance",
"capabilities": {
"streaming": true,
"pushNotifications": true
},
"skills": [
{ "name": "Contract Review", "tags": ["gdpr", "legal"] }
]
}
The protocol stack
A2A doesn't work alone. It's one layer in a complete protocol stack for the Internet of Agents:
MeetLoyd is the only platform that implements all four layers in production.
How MeetLoyd implements A2A
Every MeetLoyd agent automatically gets an Agent Card. A2A is used for:
- Cross-team handoffs — Agent in Sales team delegates to agent in Legal team, both on MeetLoyd
- External collaboration — Your MeetLoyd agent discovers an agent on another platform via Agent Card
- SLIM federation — For cross-organization collaboration, A2A is wrapped in SLIM for trust verification
Unlike raw A2A (which has no governance), MeetLoyd adds SPIFFE identity, permission checks, spending controls, and audit trails to every A2A interaction.
A2A vs MCP
A common confusion:
- MCP = agent talks to a tool (CRM, database, API). One-directional: agent calls, tool responds.
- A2A = agent talks to another agent. Bidirectional: both can initiate, negotiate, stream results.
You need both. MCP gives agents hands (tools). A2A gives agents colleagues (other agents).