Ask HN: Is anyone using the A2A protocol?

[asim]

The A2A protocol is an agent to agent protocol from Google. I was looking at it 6 months back but it didn't feel like I really understood how to use it at that point. Probably because we were all still trying to figure out agents and then the MCP protocol became quite a big deal. But now I'm starting to think that once an agent has tools and services and data and then contacts. Actually, the point of interaction becomes the agent itself and then if you build other agents you would want them to interact because they have the most relevant context and ability to answer whatever queries. So I was just curious to know if anyone is using this yet?

https://github.com/a2aproject/A2A

[techwizrd]

I'm using it at work as well. It's quite challenging to manage.

[calny]

Not to great effect, AFAIK. Laurie Voss (creator of npm) had a good presentation a few months back on all the different agent interaction protocols, and was skeptical whether they (including A2A) added much value. https://youtu.be/kqB_xML1SfA?si=lxehX1-_z_dBoZtQ

[lazharichir]

I am using A2A at work. It's a bit like the "microservices architecture" for agents... Allows you or teams to develop agents independently and have them interact as and when they need to. No major hurdles so far.

[dang]

Related. Others?

The Agent2Agent Protocol (A2A) - https://news.ycombinator.com/item?id=43631381 - April 2025 (280 comments)

[reactordev]

Yes. My agent speaks A2A with itself and others. But my agent is built in layers like an organization.

[bckr]

We set up something with a registry of AgentCards and a messaging system with SSE streaming—then we realized we didn’t need an agent on the other side so now we have this weird hybrid pattern.

So, no.

[nyellin]

No, it was designed on paper by someone with no understanding of prompt caching and no consideration of latency or token costs

[code51]

You mean Google doesn't understand prompt caching, latency or token costs?

Or Google teams fail to communicate for such things?

[baroiall]

enterprises are, its the future for them. Take a look: https://www.tigera.io/blog/why-we-built-lynx-bringing-contro...