---
title: "Agent2Agent: what it is | Agent MCP Directory"
description: "Agent2Agent: A protocol for agents to discover each other through an Agent Card and exchange tasks and messages. Read 4 November 2026 with sources."
canonical: https://agentmcpdirectory.com/standards/a2a
site: "Agent MCP Directory"
last_updated: 2026-11-04
section: "Standards"
---

# Agent2Agent: what it is | Agent MCP Directory

> Agent2Agent: A protocol for agents to discover each other through an Agent Card and exchange tasks and messages. Read 4 November 2026 with sources.

Source: https://agentmcpdirectory.com/standards/a2a
Site: Agent MCP Directory
Last reviewed: 2026-11-04

# Agent2Agent

Agent2Agent, maintained by A2A project, Growth Stage project at the Agentic AI Foundation (Linux Foundation-directed). A protocol for agents to discover each other through an Agent Card and exchange tasks and messages. Status: Specification 1.0.0 is the latest release; joined the Agentic AI Foundation on 27 Aug 2026.

## Fact sheet

| Name | Agent2Agent (A2A) |
| --- | --- |
| Maintainer | A2A project, Growth Stage project at the Agentic AI Foundation (Linux Foundation-directed) |
| What it is | A protocol for agents to discover each other through an Agent Card and exchange tasks and messages. |
| Status and version | Specification 1.0.0 is the latest release; joined the Agentic AI Foundation on 27 Aug 2026. |
| What it does not do | Does not define how an agent calls a plain API or a web page; it covers agent-to-agent tasks, not tool access. |

## Dated facts

-   A2A 1.0.0 defines three protocol bindings: JSON-RPC, gRPC and HTTP+JSON/REST, and allows custom bindings. ([a2a-protocol.org](https://a2a-protocol.org/latest/specification/), read 4 November 2026)
-   The Agent Card is served at /.well-known/agent-card.json and registered as a well-known URI in section 14.3. ([a2a-protocol.org](https://a2a-protocol.org/latest/specification/), read 4 November 2026)
-   A2A was accepted as a Growth Stage project at the Agentic AI Foundation on 27 Aug 2026, alongside MCP, goose and AGENTS.md. ([a2a-protocol.org](https://a2a-protocol.org/latest/blog/2026/08/27/a-new-chapter-for-a2a-joining-the-agentic-ai-foundation/), dated 27 August 2026, read 4 November 2026)
-   The spec page footer reads Copyright 2026 The Linux Foundation, Apache License 2.0. ([a2a-protocol.org](https://a2a-protocol.org/latest/specification/), read 4 November 2026)
-   Kong AI Gateway emits OpenTelemetry metrics for A2A traffic alongside MCP. ([developer.konghq.com](https://developer.konghq.com/ai-gateway/), read 4 November 2026)

## Seen in the shared crawl

| Path | Top 10,000 found | Ora leaderboard found |
| --- | --- | --- |
| /.well-known/agent-card.json | 10 of 7,470 (0.13%) | 48 of 3,368 (1.43%) |
| /.well-known/agent.json | 6 of 7,461 (0.08%) | 14 of 3,366 (0.42%) |

A path counts only when the answer is the right kind of document. Many sites answer these paths with an ordinary web page, which is not counted. See [the census](https://agentmcpdirectory.com/census/).

## Compared with

-   [MCP vs A2A](https://agentmcpdirectory.com/compare/mcp-vs-a2a/)

Edition

4 November 2026

Method

[How rows are verified](https://agentmcpdirectory.com/method/)

Data

[CSV and JSON](https://agentmcpdirectory.com/data/)

Markdown

[This page as markdown](https://agentmcpdirectory.com/standards/a2a/index.md)

## Sources

-   [Agent2Agent specification or home](https://a2a-protocol.org/latest/specification/), read 4 November 2026
-   [Agent2Agent: a2a-protocol.org/latest/blog/2026/08/27/a-new-chapter-for-a2a-joining-the-agentic-ai-foundation](https://a2a-protocol.org/latest/blog/2026/08/27/a-new-chapter-for-a2a-joining-the-agentic-ai-foundation/), read 4 November 2026
-   [Agent2Agent: developer.konghq.com/ai-gateway](https://developer.konghq.com/ai-gateway/), read 4 November 2026

Last reviewed 4 November 2026