---
title: "Agent2Agent (A2A) · Context Atlas"
description: "Agent2Agent (A2A) (Agent protocol) for coding agents: 3 sources, including an llms.txt and docs, and the files that show a project uses it."
canonical: "https://contextatlas.dev/topics/a2a"
updatedAt: "2026-10-23"
---

# Agent2Agent (A2A) · Context Atlas

> The sources Agent2Agent (A2A) publishes for coding agents. Fetch the llms.txt or Rules source first; fetch Full text sources only to search them, they are often several megabytes. Full catalog and instructions: https://contextatlas.dev/llms.txt

Last updated: 2026-10-23

### Agent2Agent (A2A)
Role: Agent protocol
Signals: @a2a-js/sdk dependency, a2a-sdk Python dependency, /.well-known/agent-card.json
- [A2A llms.txt](https://a2a-protocol.org/llms.txt): llms.txt
- [A2A protocol specification](https://a2a-protocol.org/latest/specification/): Docs
- [a2aproject/A2A](https://github.com/a2aproject/A2A): Docs

Related topics:

- [skills CLI](https://contextatlas.dev/topics/skills-cli): Agent tooling
- [MCP Inspector](https://contextatlas.dev/topics/mcp-inspector): Agent tooling
- [Coding agent CLIs](https://contextatlas.dev/topics/coding-agents): Agent tooling
- [Agent Skills](https://contextatlas.dev/topics/agent-skills): Instructions
- [Model Context Protocol](https://contextatlas.dev/topics/mcp): Tools
- [AGENTS.md](https://contextatlas.dev/topics/agents-md): Instructions