In the past 1 year, I think I've moved from MCP to A2A to Agent <> MCP back again. I have agents still talking to other Agents via A2A for some use cases, but for the most part, it's back to Agent <> MCP now; couple that with tool search/code mode (whatever you want to call it) in your Agentic AI harness, MCPs seem to be the way to go for now.
I work for a very large it department and have direct insight about any ai use - nope, not a single use case i witnessed used a2a outside a throwaway test. I still don't get a2a but you probably have to work at Google or something to see this as the solution to something.
(Based off 2-3 month-old recollection, take with a grain of salt)
I had wanted to use it for my agent "network". A2A didn't fit the use case of "trusted agent, and was bloated due to "what if rogue actor". Of course, I could have used it, with all of its roughness, but chose to just vibe my own (before Claude Teams, though I haven't really used that, I think). In the process of creating a server to handle this (I already set up a Scala webserver to administrate/orchestrate hooks). Would love to hear others' suggestions for this.
I've changed my mind a few times on this, but given how substantial the adoption for MCP has been (Claude and OpenAI both use it for their native integrations) its only a matter of time before consolidation happens.
There's a way higher incentive to build an MCP server than an A2A one, and unless Google makes their default AI search a native A2A client it doesn't feel like it will get the momentum it needs to take off.
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
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.
This was my assumption. Agents will supersede services. There will be many companies way ahead of the curve and the rest of the industry will take 5-10 years to catch up.
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.
A2A is a very high level protocol that's meant to be an entry point for the actual network protocols that allow agents to communicate with others like HTTP, gRPC, and others. The promise of no-code means the concept has to exist as an abstraction.
There's a Kaggle course going on where Google discusses A2A and their thoughts on it. If you're a pure vibe coder who doesn't know how to code, A2A is for you. If you know the basics of programming and could even do some web crawling, there are many accessible options.
Google and the industry is honing in on these vibe coders who will look at 10 million tokens consumed to make a checklist application and think nothing of it. The agent to agent (A2A) protocol is for them. Personally, I think it's useful to describe what I'm already doing to people who aren't experts.
In the past 1 year, I think I've moved from MCP to A2A to Agent <> MCP back again. I have agents still talking to other Agents via A2A for some use cases, but for the most part, it's back to Agent <> MCP now; couple that with tool search/code mode (whatever you want to call it) in your Agentic AI harness, MCPs seem to be the way to go for now.
I work for a very large it department and have direct insight about any ai use - nope, not a single use case i witnessed used a2a outside a throwaway test. I still don't get a2a but you probably have to work at Google or something to see this as the solution to something.
(Based off 2-3 month-old recollection, take with a grain of salt)
I had wanted to use it for my agent "network". A2A didn't fit the use case of "trusted agent, and was bloated due to "what if rogue actor". Of course, I could have used it, with all of its roughness, but chose to just vibe my own (before Claude Teams, though I haven't really used that, I think). In the process of creating a server to handle this (I already set up a Scala webserver to administrate/orchestrate hooks). Would love to hear others' suggestions for this.
I've changed my mind a few times on this, but given how substantial the adoption for MCP has been (Claude and OpenAI both use it for their native integrations) its only a matter of time before consolidation happens.
There's a way higher incentive to build an MCP server than an A2A one, and unless Google makes their default AI search a native A2A client it doesn't feel like it will get the momentum it needs to take off.
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
I'm using it at work as well. It's quite challenging to manage.
Seems like over engineering just build an API in front of your agent, give the other agent the spec in a markdown file.
why dropbox when you can just rsync
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.
This was my assumption. Agents will supersede services. There will be many companies way ahead of the curve and the rest of the industry will take 5-10 years to catch up.
Related. Others?
The Agent2Agent Protocol (A2A) - https://news.ycombinator.com/item?id=43631381 - April 2025 (280 comments)
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.
Yes. My agent speaks A2A with itself and others. But my agent is built in layers like an organization.
No, it was designed on paper by someone with no understanding of prompt caching and no consideration of latency or token costs
You mean Google doesn't understand prompt caching, latency or token costs?
Or Google teams fail to communicate for such things?
A2A is a very high level protocol that's meant to be an entry point for the actual network protocols that allow agents to communicate with others like HTTP, gRPC, and others. The promise of no-code means the concept has to exist as an abstraction.
There's a Kaggle course going on where Google discusses A2A and their thoughts on it. If you're a pure vibe coder who doesn't know how to code, A2A is for you. If you know the basics of programming and could even do some web crawling, there are many accessible options.
Google and the industry is honing in on these vibe coders who will look at 10 million tokens consumed to make a checklist application and think nothing of it. The agent to agent (A2A) protocol is for them. Personally, I think it's useful to describe what I'm already doing to people who aren't experts.
I uh…still use tmux send-keys. I’ll change as soon as I find a use-case it doesn’t solve. ¯\_(ツ)_/¯
enterprises are, its the future for them. Take a look: https://www.tigera.io/blog/why-we-built-lynx-bringing-contro...