# Agent2Agent (A2A) Protocol

Open protocol for agents from different vendors to discover and talk to each other. Agent2Agent (A2A) Protocol is free, with no paid plan attached, at github.com.

## Facts

- **Pricing tier:** Free
- **Works on:** Self-hosted, API
- **Works in browser:** No

## Capabilities

- Open protocol for agents from different vendors to discover and talk to each other
- SDKs in Python, JS, Java, .NET and Go
- Now hosted by the Linux Foundation
- Complements MCP for agent-to-agent communication

## FAQ

### What is Agent2Agent (A2A) Protocol?

Agent2Agent (A2A) Protocol is listed under MCP Ecosystem, in the AI Agents & Automation category on Flocci AI Tools. Open protocol for agents from different vendors to discover and talk to each other. It is free, with no paid plan attached, and it lives at github.com.

### Is Agent2Agent (A2A) Protocol free?

Agent2Agent (A2A) Protocol is listed as fully free — there is no paid tier attached to it in the catalog. That makes it one of the 397 entries on Flocci AI Tools with no upgrade path built in.

### Can I use Agent2Agent (A2A) Protocol in a browser, or is there an app?

Agent2Agent (A2A) Protocol needs to be installed or self-hosted — it doesn't run in a browser tab. It is available on self-hosting and an API.

### What can Agent2Agent (A2A) Protocol do?

Agent2Agent (A2A) Protocol does 4 things the catalog singles out: Open protocol for agents from different vendors to discover and talk to each other; sdks in python, js, java, .net and go; now hosted by the linux foundation; complements mcp for agent-to-agent communication.

### What is the best free alternative to Agent2Agent (A2A) Protocol?

MCP Registry (Official) is the closest free alternative: it sits in the same MCP Ecosystem sub-category and is free. FastMCP, GitHub MCP Server and MCP Inspector also start free. The full list is on the alternatives page.

## Related

- [Agent2Agent (A2A) Protocol alternatives](https://aitools.flocci.in/alternatives/agent2agent-a2a-protocol)
- [MCP Ecosystem](https://aitools.flocci.in/category/ai-agents-automation/mcp-ecosystem)
- [Best free MCP servers, registries and toolkits](https://aitools.flocci.in/best/best-mcp-ecosystem)
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Source: Flocci AI Tools — https://aitools.flocci.in/tool/agent2agent-a2a-protocol

Facts last verified: October 2026