6 ms·

Agent Client Protocol (ACP)

281 points by vinhnx 1y ago

baggiponte 1y ago
Really hope for this to get traction so I’m not bound to the usual IDE
johnhamlin 1y ago
I’m going to be hungry all day, everyday if this catches on and we call it ACP
- falcor84 1y ago
  Arroz con Pollo? Now that's an abbreviation I've not heard in a long time.
cube2222 1y ago
Fingers crossed for this - it seems like Zed is kinda “going back to the roots” (of working on collaboration) and leaving this in place to disrupt the agentic IDE category (and make themselves not have to spend time on competing in it). Curious to see how adoption among cli agents will go (it’s nice to see Gemini cli already in). The level of competition in the LLM and coding assistant market is always nice to see, and this only helps to make costs of switching between offerings even smaller.
- giancarlostoro 1y ago
  I'm basically sold on Zed, it has everything I have wanted from an editor for years, and that's without the amazing other things that they added that I wasn't even envisioning. For years I've prototyped a few different editors because of frustration with the status quo. There's a lot of work that goes into a good editor, and Zed has definitely done the legwork. I welcome them openly collaborating.
  - iamkd 1y ago
    Zed is awesome, but the absence of side-by-side diffs just drives me crazy, so I'm back to Cursor / VSCode. Turns out I can't work without it. This is the top rated discussion on Github though: https://github.com/zed-industries/zed/discussions/26770 https://github.com/zed-industries/zed/discussions/26770
    - Aeolun 1y ago
      I’m sure anyone invested enough could contribute that xD Like, I agree that that’s the thing I want most out of Zed right now, but not enough to do it myself.
  - 9dev 1y ago
    You can take my IntelliJ IDE out of my cold, dead hands. I don’t understand why anyone would want to miss out on all the automatic inference and interlinked code base, the integrated tooling… Every time I try something like Zed or VS Code, I end up disappointed or install a no longer supported plugin only to learn it falls way short. Yes, Zed's startup time is way better, and it definitely feels snappier. But when I work on code, I need to jump around the code. I want the debugger to show me the current line in the file, annotating the value of every variable right in the source. I want to jump to property usages. I want to automatically rename a function everywhere intelligently, not using search-replace. I want to get completion for my database tables, and browse them from the IDE. And lots more.
    - hactually 1y ago
      It's fine, it sounds like you're an enterprise programmer and that suits your role/use case. I use zed with the inbuilt terminal, additional terminals + tools like pgcli and docker. I would feel trapped/impotent using an IDE, esp combined with the lack of snappiness a java app gives you.
      - 9dev 1y ago
        Couldn’t be further from Enterprise luckily, but it leaves me wondering if I’m missing the forest for the trees? Maybe it’s just a difference in working style. I would feel exhausted by having to learn and maintain a bunch of tools instead of just one, sprinkled with occasional anxiety if there is a better or upstart competing tool that I should be using.
- WD-42 1y ago
  Seriously. I really hope this puts an end to the crappy VS Code forks so Zed can start getting the credit it’s due. These ai editors have really sucked all the air out of the room.
faangguyindia 1y ago
when is it coming to vscode?
fijiaarone 1y ago
The protocol for interacting with code is files and text. You need to define an interface for Ai to click buttons? Or to create keyboard macros that simulate clicking buttons? We are all doomed!
- baggiponte 1y ago
  I’m afraid you missed a bit the mark :( This is the equivalent of LSP but for coding agents. So any editor does not have to rebuild an interface to support each and every new one.
  - jmull 1y ago
    The question is why… The purpose of an ide is to pull together the tools a developer needs to develop software… first, reading/navigating and writing code, next running and debugging code, then (potentially) a variety of other tools: profilers, doc browsers, etc… all into a unified UI. But coding agents seem to already be able to use the command line and mcp quite well to do this. So why mediate using these tools through an IDE (over a new protocol) rather than just using the tools directly through the command line or mcp? It’s two extra levels of indirection, so there needs to be a really good reason to do it. There may very well be some actual problem this solves, but I don’t know what it is.
    - lyu07282 1y ago
      > So why mediate using these tools through an IDE (over a new protocol) rather than just using the tools directly through the command line or mcp The IDE is in-between because it asks the user for confirmation before doing anything, if that's what you are asking. It's not adding any indirection or something, this is just how coding agents talk to the IDE already, all this does is standardize the language they speak which would be a win for everybody.
- quotemstr 1y ago
  There's a long history of REPL interaction protocols decoupling development environments from tools and making things nicer overall. This thing is an empty in the same tradition. (That said, I'm not convinced its author knew the tradition existed.) It's like the Jupyter protocol, from which people do derive utility.
Lucasoato 1y ago
I really hope that APC will get the necessary traction from the community, even if I suspect that many standards that are currently proposed in the LLM field will be abandoned soon. https://xkcd.com/927/ https://xkcd.com/927/
mg 1y ago
I'm fine with treating AI like a human developer: I ask AI to write a feature (or fix a bug, or do a refactoring) and then I read the commit. If the commit is not to my liking, I "git reset --hard", improve my prompt and ask the AI to do the task again. I call this "prompt coding": https://www.gibney.org/prompt_coding https://www.gibney.org/prompt_coding This way, there is no interaction between my coding environment and the AI at all. Just like working with a human developer does not involve them doing anything in my editor.
- Disposal8433 1y ago
  > Nowadays, it is better to write prompts Very big doubt. AI can help for a few very specific tasks, but the hallucinations still happen, and making things up (especially APIs) is unacceptable.
  - NitpickLawyer 1y ago
    > but the hallucinations still happen, and making things up (especially APIs) is unacceptable. The new models are much better at reading the codebase first, and sticking to "use the APIs / libraries already included". Also, for new libraries there's context7 that brings in up-to-date docs. Again, newer models know how to use it (even gpt5-mini works fine with it).
    - sigseg1v 1y ago
      What size of codebases are we talking here? I've had a lot of issues trying to do pretty much anything across a 1.7 million LOC codebase and generally found it faster to use traditional IDE functionalities. I've had much more success with things under 20k LOC but that isn't the stuff that I really need any assistance with.
  - wongarsu 1y ago
    In languages with strong compile-time checks (like say rust) the obvious problems can mostly be solved by having the agent try to compile the program as a last step, and most agents now do that on their own. In cases where that doesn't work (more permissive languages like python, or http APIs) you can have the AI write tests and execute them. Or ask the AI to prototype and test features separately before adding them to the codebase. Adding MCP servers with documentation also helps a ton. The real issues I'm struggling with are more subtle, like unnecessary code duplication, code that seems useful but is never called, doing the right work but in the wrong place, security issues, performance issues, not implementing the prompt correctly when it's not straight forward, implementing the prompt verbatim when a closer inspection of the libraries and technologies used reveals a much better way, etc. Mostly things you will catch in code review if you really pay attention. But whether that's faster than doing the task yourself greatly depends on the task at hand
qiine 1y ago
The folks that makes CodeCompagnion are doing interesting things!
xmorse 1y ago
Zed should start improving the diff view. It's one of the worst. It does not even have word level diff highlight or split diff view
- nicce 1y ago
  Only reason I use VSCode these days is Git Merge Editor.
- djim1337 1y ago
  [dead]
darkbatman 1y ago
With already https://agentcommunicationprotocol.dev https://agentcommunicationprotocol.dev (ACP) same name seems confusing now. even though differences are there in both.
- schwentkerr 1y ago
  IBM announced in March 2025 its Agent Communication Protocol (ACP) but is now abandoning the ACP name and merging ACP efforts with Google’s Agent2Agent (A2A) protocol at the Linux Foundation. The ACP team is winding down as the industry backs A2A for open, community-driven AI agent interoperability under Linux Foundation governance. This move aims to unify protocols and avoid fragmentation in AI agent standards. https://lfaidata.foundation/communityblog/2025/08/29/acp-joins-forces-with-a2a-under-the-linux-foundations-lf-ai-data/ https://lfaidata.foundation/communityblog/2025/08/29/acp-joi...
  - derefr 1y ago
    That seems odd. Even with an A2A protocol, don’t you still need to standardize a client “surface” or “API” or whatever, so agents can describe IDE actions they want to trigger in the expected terms over that protocol? Or is A2A like USB, where it acts as both a registry of, and “standardized standardization process” for, suites of concrete message types for each use-case? Like, yeah, when a "client" drives an "agent", that's no different than what any generic "agent" would be doing to drive an "agent"; an IDE or what-have-you can just act as the "parent agent" in that context. But when an "agent" is driving a "client", that's all about the "agent" understanding that the "client" isn't just some generic token-driven inference process, but an actual bundle of algorithms that does certain concrete things, and has to be spoken to a certain way to get it to do those concrete things. I had assumed that IBM's older ACP was in large part concerned with formalizing that side of interoperation. Am I wrong?
greatgib 1y ago
The big question is why it can't be just a LSP server or extension to the LSP protocol to provide all that might be needed by the LLM.
- gtsop 1y ago
  Because there is no ai hype in LSP. AI is literally going through the same phase as early javascript libraries did. An explosion of tools, completely ignoring/bypassing previous accumulated knowledge, solving the wrong problems with the wrong tools. And this will pile up the bloat stack, similar to js libraries, because new problems will rise from the wrong solutions, requiring even more wrong solutions to be incorporated in the stack.
  - nsonha 1y ago
    did you actually think about the question or you just want to shout an opinion? The question doesn't even make sense, there is no overlap between LSP and ACP
    - gtsop 1y ago
      Your response is an exact proof of what I said in my comment. Thanks Edit: Ok elaboration for the well intended. There is a HUGE overlap of LSP and ACP. LSP solves the problem of "oh we have many IDEs and many language integration plugins, we have an NxM problem, let's make it a N+M". ACP goes to do exactly that but for agents (which is an implementation detail), which means they could very well piggy back on top of LSP
      - nsonha 1y ago
        The overlap being... they are both... protocols?
      - makeboss 1y ago
        This kind of arguments don't make sense because of scope creep. LSP is for programming languages, why would the maintainers of LSP consider AI agents as a valid language server? And ACP is useful beyond code editors that supporting LSP just for the sake of it makes even less sense.
awestroke 1y ago
Claude, come up with a protocol for communicating between AI agents and IDEs/editors. Create node, python and rust libraries. Create a website with a landing page
- ivape 1y ago
  lol. So hedonistic.
- bsimpson 1y ago
  Honestly, I'm tempted to see if Gemini can write a Sublime Text plugin that implements this protocol. Feels like a lot of mindshare has shifted towards VSCode, so that's where the tooling investment goes. I don't want to be forced off of subl because new tools stop supporting it - it's a great editor, and it's not sponsored by a massive company.
  - kgthegreat 1y ago
    Shouldn’t be too hard. I wrote this emacs plugin to do similar things but without this protocol - https://github.com/kgthegreat/protagentic https://github.com/kgthegreat/protagentic . Heavily used AI assisted coding for it.
  - pickledish 1y ago
    Yeah agreed! As you suggest, I've had a moderately successful time trying to get AI to write its own Sublime Text plugins so our favorite editor doesn't get left behind, so might be cool to try with this too? https://github.com/pickledish/llm-completion https://github.com/pickledish/llm-completion
  - favflam 1y ago
    Is there an open LSP standard that allows IDEs like Lazyvim to work?
    - Karrot_Kream 1y ago
      LSP is an open standard. Protocols like this need to be implemented in editor.
adobrawy 1y ago
MCP also started as JSON-RPC over stdio. With solutions like GitHub Codespaces, devcontainers, or "background agents", I wonder if we'll see the development of JSON over SSE. Currently, my environment uses Claude Code on bare metal, and my application runs in a container, and the agent can do "docker compose exec backend" without any restrictions (YOLO). My biggest obstacles to adopting workflows with git worktree are the need to share the database engine (local resource constrains) and the initial migration time. Offloading to cloud might be interesting for that.
hari-trata 1y ago
I don’t see why we need so many protocols. In such a greenfield tech, many are eager to define rules. There’s already a protocol called AG-UI that does the similar thing, but even its purpose isn’t entirely clear to me. Rather than rushing to create standards, I think the focus should be on building practical implementations, AI-centric UI components that actually help developers design more AI-friendly interfaces. Once the space matures and stabilizes, that’s when standardization will make more sense. Right now, it feels too early.
- triyambakam 1y ago
  I do agree it seems like too many protocols. I wonder why this couldn't be mcp. But regarding ag-ui in its name it's for UI - streaming from a backend agent to a client frontend. I actually have been working a lot with it this week.
  - djim1337 1y ago
    [dead]
- ivanjermakov 1y ago
  > I don’t see why we need so many protocols One great reason is to avoid M*N problem: https://matklad.github.io/2022/04/25/why-lsp.html https://matklad.github.io/2022/04/25/why-lsp.html
- nsonha 1y ago
  I don't know about other protocols but for this one it's because AI vendors decided to ship their agents in the form of TUIs, which are not programmable. They need to be wrapped into something to be build on top of. I actually prefer something like opencode which is one TUI to rule them all (albeit still lacking in some area), it also provides an an SDK that abstracts away the underlying model.
acomagu 1y ago
I would love it, but please don't add JSON-RPC to the world... It's too heavy for editor.
- mi_lk 1y ago
  Is there a better option?
- quotemstr 1y ago
  Anyone else noticing an uptick in confidently stated nonsense on HN? To write that JSON-RPC is "too heavy for editor", you have to not only misunderstand the cost of JSON encoding (trivial) but also the frequency of editor-tool interaction (seldom) and volume of data transferred (negligible). In addition, you have to look at LSP, MCP, and other JSON-y protocols and say "yep. There's where the UI latency is. Got it.". (Nope) Are people who assert that JSON-RPC is "heavy" writing code we all rely on?
  - willm 1y ago
    Harsh. But fair. JSON-RPC is one of the leanest protocols out there.
quotemstr 1y ago
I see they've also caught the RFC2119 bug. This "MUST", "SHALL", "MAY" thing is a linguistic blight on our standards landscape and should be eradicated. HTML5 is written without this unnecessary level of linguistic pretense and works fine. If your proposed spec is full of "SHALL", "MUST", and "MAY", I'm going to dock you ten points of credibility from the outset. It's a signal you've set out to imitate the vibes of seminal RFC specs without independently considering the substance.
- PhilipRoman 1y ago
  I don't know if your complaint is specifically about the capitalization, but I find these clear rules useful when interpreting specifications.
- elteto 1y ago
  We SHALL replace them with MAYBE, IF YOU FEEL LIKE IT, and OR WHATEVER. Will sure make for lighter reading.
lvl155 1y ago
Why don’t they focus on IDE first? I still can’t use their IDE as my daily. They also need to hire someone for UI. It took me 10 minutes to figure out how to bring up their AI chat window.
- Aeolun 1y ago
  If it took you 10 minutes to bring that up I can’t understand why. Presumably you’ve switched to any of the other panels in Zed before?
jasonjmcghee 1y ago
Another discussion on the same topic from 3 days ago: https://news.ycombinator.com/item?id=45038710 https://news.ycombinator.com/item?id=45038710
lukaslalinsky 1y ago
I really wish Anthropic will adopt this for Claude Code, and I hope it provides at least the kind of integration they have with VS Code. Would be nice if it had access to at least diagnostics from the editor.
vlaaad 1y ago
I love this idea; I hope it gains traction. One thing that is not clear to me is file search vs unsaved files. It's common for agents to use, e.g., ripgrep to search the file system. But if the communication protocol includes read/write access to unsaved files, there is a desync in terms of accuracy.. rg can't search unsaved files.
huflungdung 1y ago
[dead]
tekacs 1y ago
It's interesting to see that there's the beginnings of an implementation for Claude Code, here: https://github.com/zed-industries/zed/blob/main/crates%2Fagent_servers%2Fsrc%2Fclaude.rs https://github.com/zed-industries/zed/blob/main/crates%2Fage... https://www.npmjs.com/package/@zed-industries/claude-code-acp https://www.npmjs.com/package/@zed-industries/claude-code-ac... Even though that doesn't seem to be mentioned on the site yet.
Eduard 1y ago
naming things isn't that hard. at least put something with AI/LLM and code/IDE in the name.
akattelu 1y ago
So much negativity in this thread. After seeing the recent demo of gemini cli working in zed, I'm actually pretty excited for standardization in this space. Helix has been my favorite editor ever since I started using it, but the lack of integrated AI features has been becoming more of a deal-breaker for me lately. Though, I can see why the maintainers are hesitant to build for it, because there hasn't been a standardized protocol. I hope ACP changes that.
rmonvfer 1y ago
I’ve been writing a tool to enable Claude Code to use ACP (because I use CC and Zed a lot) and so far I’ve been pretty successful (using the Claude Code SDK and the ACP Client library) although there are some rough edges. I will polish it a little bit and publish it tomorrow I guess.
- vincelt 1y ago
  Found this repo the other day in case that's useful: https://github.com/Xuanwo/acp-claude-code https://github.com/Xuanwo/acp-claude-code
upcoming-sesame 1y ago
the difference between using, for example, Gemini via ACP vs Gemini via the ide own agent is not so clear
cranberryturkey 1y ago
How's this better than MCP?
joeyguerra 1y ago
Does anyone else find it funny that LLMs need a protocol to execute tooling? Like, it understands language, right?
csomar 1y ago
I feel these solutions are approaching the problem backward. What I want is not a Claude Code in my Neovim but a Neovim in my Claude Code. That is, when the agent fails, I am able to hop in momentarily with all the perks of an IDE (ie: type-setter, LSP, etc.) and do some editing and then give control back to the agent.

281 points by vinhnx 1y ago

baggiponte 1y ago

Really hope for this to get traction so I’m not bound to the usual IDE

johnhamlin 1y ago

I’m going to be hungry all day, everyday if this catches on and we call it ACP

falcor84 1y ago
Arroz con Pollo? Now that's an abbreviation I've not heard in a long time.

cube2222 1y ago

Fingers crossed for this - it seems like Zed is kinda “going back to the roots” (of working on collaboration) and leaving this in place to disrupt the agentic IDE category (and make themselves not have to spend time on competing in it). Curious to see how adoption among cli agents will go (it’s nice to see Gemini cli already in). The level of competition in the LLM and coding assistant market is always nice to see, and this only helps to make costs of switching between offerings even smaller.

giancarlostoro 1y ago
I'm basically sold on Zed, it has everything I have wanted from an editor for years, and that's without the amazing other things that they added that I wasn't even envisioning. For years I've prototyped a few different editors because of frustration with the status quo. There's a lot of work that goes into a good editor, and Zed has definitely done the legwork. I welcome them openly collaborating.
- iamkd 1y ago
  Zed is awesome, but the absence of side-by-side diffs just drives me crazy, so I'm back to Cursor / VSCode. Turns out I can't work without it. This is the top rated discussion on Github though: https://github.com/zed-industries/zed/discussions/26770 https://github.com/zed-industries/zed/discussions/26770
  - Aeolun 1y ago
    I’m sure anyone invested enough could contribute that xD Like, I agree that that’s the thing I want most out of Zed right now, but not enough to do it myself.
- 9dev 1y ago
  You can take my IntelliJ IDE out of my cold, dead hands. I don’t understand why anyone would want to miss out on all the automatic inference and interlinked code base, the integrated tooling… Every time I try something like Zed or VS Code, I end up disappointed or install a no longer supported plugin only to learn it falls way short. Yes, Zed's startup time is way better, and it definitely feels snappier. But when I work on code, I need to jump around the code. I want the debugger to show me the current line in the file, annotating the value of every variable right in the source. I want to jump to property usages. I want to automatically rename a function everywhere intelligently, not using search-replace. I want to get completion for my database tables, and browse them from the IDE. And lots more.
  - hactually 1y ago
    It's fine, it sounds like you're an enterprise programmer and that suits your role/use case. I use zed with the inbuilt terminal, additional terminals + tools like pgcli and docker. I would feel trapped/impotent using an IDE, esp combined with the lack of snappiness a java app gives you.
    - 9dev 1y ago
      Couldn’t be further from Enterprise luckily, but it leaves me wondering if I’m missing the forest for the trees? Maybe it’s just a difference in working style. I would feel exhausted by having to learn and maintain a bunch of tools instead of just one, sprinkled with occasional anxiety if there is a better or upstart competing tool that I should be using.
WD-42 1y ago
Seriously. I really hope this puts an end to the crappy VS Code forks so Zed can start getting the credit it’s due. These ai editors have really sucked all the air out of the room.

faangguyindia 1y ago

when is it coming to vscode?

fijiaarone 1y ago

The protocol for interacting with code is files and text. You need to define an interface for Ai to click buttons? Or to create keyboard macros that simulate clicking buttons? We are all doomed!

baggiponte 1y ago
I’m afraid you missed a bit the mark :( This is the equivalent of LSP but for coding agents. So any editor does not have to rebuild an interface to support each and every new one.
- jmull 1y ago
  The question is why… The purpose of an ide is to pull together the tools a developer needs to develop software… first, reading/navigating and writing code, next running and debugging code, then (potentially) a variety of other tools: profilers, doc browsers, etc… all into a unified UI. But coding agents seem to already be able to use the command line and mcp quite well to do this. So why mediate using these tools through an IDE (over a new protocol) rather than just using the tools directly through the command line or mcp? It’s two extra levels of indirection, so there needs to be a really good reason to do it. There may very well be some actual problem this solves, but I don’t know what it is.
  - lyu07282 1y ago
    > So why mediate using these tools through an IDE (over a new protocol) rather than just using the tools directly through the command line or mcp The IDE is in-between because it asks the user for confirmation before doing anything, if that's what you are asking. It's not adding any indirection or something, this is just how coding agents talk to the IDE already, all this does is standardize the language they speak which would be a win for everybody.
quotemstr 1y ago
There's a long history of REPL interaction protocols decoupling development environments from tools and making things nicer overall. This thing is an empty in the same tradition. (That said, I'm not convinced its author knew the tradition existed.) It's like the Jupyter protocol, from which people do derive utility.

Lucasoato 1y ago

I really hope that APC will get the necessary traction from the community, even if I suspect that many standards that are currently proposed in the LLM field will be abandoned soon. https://xkcd.com/927/ https://xkcd.com/927/

mg 1y ago

I'm fine with treating AI like a human developer: I ask AI to write a feature (or fix a bug, or do a refactoring) and then I read the commit. If the commit is not to my liking, I "git reset --hard", improve my prompt and ask the AI to do the task again. I call this "prompt coding": https://www.gibney.org/prompt_coding https://www.gibney.org/prompt_coding This way, there is no interaction between my coding environment and the AI at all. Just like working with a human developer does not involve them doing anything in my editor.

Disposal8433 1y ago
> Nowadays, it is better to write prompts Very big doubt. AI can help for a few very specific tasks, but the hallucinations still happen, and making things up (especially APIs) is unacceptable.
- NitpickLawyer 1y ago
  > but the hallucinations still happen, and making things up (especially APIs) is unacceptable. The new models are much better at reading the codebase first, and sticking to "use the APIs / libraries already included". Also, for new libraries there's context7 that brings in up-to-date docs. Again, newer models know how to use it (even gpt5-mini works fine with it).
  - sigseg1v 1y ago
    What size of codebases are we talking here? I've had a lot of issues trying to do pretty much anything across a 1.7 million LOC codebase and generally found it faster to use traditional IDE functionalities. I've had much more success with things under 20k LOC but that isn't the stuff that I really need any assistance with.
- wongarsu 1y ago
  In languages with strong compile-time checks (like say rust) the obvious problems can mostly be solved by having the agent try to compile the program as a last step, and most agents now do that on their own. In cases where that doesn't work (more permissive languages like python, or http APIs) you can have the AI write tests and execute them. Or ask the AI to prototype and test features separately before adding them to the codebase. Adding MCP servers with documentation also helps a ton. The real issues I'm struggling with are more subtle, like unnecessary code duplication, code that seems useful but is never called, doing the right work but in the wrong place, security issues, performance issues, not implementing the prompt correctly when it's not straight forward, implementing the prompt verbatim when a closer inspection of the libraries and technologies used reveals a much better way, etc. Mostly things you will catch in code review if you really pay attention. But whether that's faster than doing the task yourself greatly depends on the task at hand

qiine 1y ago

The folks that makes CodeCompagnion are doing interesting things!

xmorse 1y ago

Zed should start improving the diff view. It's one of the worst. It does not even have word level diff highlight or split diff view

nicce 1y ago
Only reason I use VSCode these days is Git Merge Editor.
djim1337 1y ago
[dead]

darkbatman 1y ago

With already https://agentcommunicationprotocol.dev https://agentcommunicationprotocol.dev (ACP) same name seems confusing now. even though differences are there in both.

schwentkerr 1y ago
IBM announced in March 2025 its Agent Communication Protocol (ACP) but is now abandoning the ACP name and merging ACP efforts with Google’s Agent2Agent (A2A) protocol at the Linux Foundation. The ACP team is winding down as the industry backs A2A for open, community-driven AI agent interoperability under Linux Foundation governance. This move aims to unify protocols and avoid fragmentation in AI agent standards. https://lfaidata.foundation/communityblog/2025/08/29/acp-joins-forces-with-a2a-under-the-linux-foundations-lf-ai-data/ https://lfaidata.foundation/communityblog/2025/08/29/acp-joi...
- derefr 1y ago
  That seems odd. Even with an A2A protocol, don’t you still need to standardize a client “surface” or “API” or whatever, so agents can describe IDE actions they want to trigger in the expected terms over that protocol? Or is A2A like USB, where it acts as both a registry of, and “standardized standardization process” for, suites of concrete message types for each use-case? Like, yeah, when a "client" drives an "agent", that's no different than what any generic "agent" would be doing to drive an "agent"; an IDE or what-have-you can just act as the "parent agent" in that context. But when an "agent" is driving a "client", that's all about the "agent" understanding that the "client" isn't just some generic token-driven inference process, but an actual bundle of algorithms that does certain concrete things, and has to be spoken to a certain way to get it to do those concrete things. I had assumed that IBM's older ACP was in large part concerned with formalizing that side of interoperation. Am I wrong?

greatgib 1y ago

The big question is why it can't be just a LSP server or extension to the LSP protocol to provide all that might be needed by the LLM.

gtsop 1y ago
Because there is no ai hype in LSP. AI is literally going through the same phase as early javascript libraries did. An explosion of tools, completely ignoring/bypassing previous accumulated knowledge, solving the wrong problems with the wrong tools. And this will pile up the bloat stack, similar to js libraries, because new problems will rise from the wrong solutions, requiring even more wrong solutions to be incorporated in the stack.
- nsonha 1y ago
  did you actually think about the question or you just want to shout an opinion? The question doesn't even make sense, there is no overlap between LSP and ACP
  - gtsop 1y ago
    Your response is an exact proof of what I said in my comment. Thanks Edit: Ok elaboration for the well intended. There is a HUGE overlap of LSP and ACP. LSP solves the problem of "oh we have many IDEs and many language integration plugins, we have an NxM problem, let's make it a N+M". ACP goes to do exactly that but for agents (which is an implementation detail), which means they could very well piggy back on top of LSP
    - nsonha 1y ago
      The overlap being... they are both... protocols?
    - makeboss 1y ago
      This kind of arguments don't make sense because of scope creep. LSP is for programming languages, why would the maintainers of LSP consider AI agents as a valid language server? And ACP is useful beyond code editors that supporting LSP just for the sake of it makes even less sense.

awestroke 1y ago

Claude, come up with a protocol for communicating between AI agents and IDEs/editors. Create node, python and rust libraries. Create a website with a landing page

ivape 1y ago
lol. So hedonistic.
bsimpson 1y ago
Honestly, I'm tempted to see if Gemini can write a Sublime Text plugin that implements this protocol. Feels like a lot of mindshare has shifted towards VSCode, so that's where the tooling investment goes. I don't want to be forced off of subl because new tools stop supporting it - it's a great editor, and it's not sponsored by a massive company.
- kgthegreat 1y ago
  Shouldn’t be too hard. I wrote this emacs plugin to do similar things but without this protocol - https://github.com/kgthegreat/protagentic https://github.com/kgthegreat/protagentic . Heavily used AI assisted coding for it.
- pickledish 1y ago
  Yeah agreed! As you suggest, I've had a moderately successful time trying to get AI to write its own Sublime Text plugins so our favorite editor doesn't get left behind, so might be cool to try with this too? https://github.com/pickledish/llm-completion https://github.com/pickledish/llm-completion
- favflam 1y ago
  Is there an open LSP standard that allows IDEs like Lazyvim to work?
  - Karrot_Kream 1y ago
    LSP is an open standard. Protocols like this need to be implemented in editor.

adobrawy 1y ago

MCP also started as JSON-RPC over stdio. With solutions like GitHub Codespaces, devcontainers, or "background agents", I wonder if we'll see the development of JSON over SSE. Currently, my environment uses Claude Code on bare metal, and my application runs in a container, and the agent can do "docker compose exec backend" without any restrictions (YOLO). My biggest obstacles to adopting workflows with git worktree are the need to share the database engine (local resource constrains) and the initial migration time. Offloading to cloud might be interesting for that.

hari-trata 1y ago

I don’t see why we need so many protocols. In such a greenfield tech, many are eager to define rules. There’s already a protocol called AG-UI that does the similar thing, but even its purpose isn’t entirely clear to me. Rather than rushing to create standards, I think the focus should be on building practical implementations, AI-centric UI components that actually help developers design more AI-friendly interfaces. Once the space matures and stabilizes, that’s when standardization will make more sense. Right now, it feels too early.

triyambakam 1y ago
I do agree it seems like too many protocols. I wonder why this couldn't be mcp. But regarding ag-ui in its name it's for UI - streaming from a backend agent to a client frontend. I actually have been working a lot with it this week.
- djim1337 1y ago
  [dead]
ivanjermakov 1y ago
> I don’t see why we need so many protocols One great reason is to avoid M*N problem: https://matklad.github.io/2022/04/25/why-lsp.html https://matklad.github.io/2022/04/25/why-lsp.html
nsonha 1y ago
I don't know about other protocols but for this one it's because AI vendors decided to ship their agents in the form of TUIs, which are not programmable. They need to be wrapped into something to be build on top of. I actually prefer something like opencode which is one TUI to rule them all (albeit still lacking in some area), it also provides an an SDK that abstracts away the underlying model.

acomagu 1y ago

I would love it, but please don't add JSON-RPC to the world... It's too heavy for editor.

mi_lk 1y ago
Is there a better option?
quotemstr 1y ago
Anyone else noticing an uptick in confidently stated nonsense on HN? To write that JSON-RPC is "too heavy for editor", you have to not only misunderstand the cost of JSON encoding (trivial) but also the frequency of editor-tool interaction (seldom) and volume of data transferred (negligible). In addition, you have to look at LSP, MCP, and other JSON-y protocols and say "yep. There's where the UI latency is. Got it.". (Nope) Are people who assert that JSON-RPC is "heavy" writing code we all rely on?
- willm 1y ago
  Harsh. But fair. JSON-RPC is one of the leanest protocols out there.

quotemstr 1y ago

I see they've also caught the RFC2119 bug. This "MUST", "SHALL", "MAY" thing is a linguistic blight on our standards landscape and should be eradicated. HTML5 is written without this unnecessary level of linguistic pretense and works fine. If your proposed spec is full of "SHALL", "MUST", and "MAY", I'm going to dock you ten points of credibility from the outset. It's a signal you've set out to imitate the vibes of seminal RFC specs without independently considering the substance.

PhilipRoman 1y ago
I don't know if your complaint is specifically about the capitalization, but I find these clear rules useful when interpreting specifications.
elteto 1y ago
We SHALL replace them with MAYBE, IF YOU FEEL LIKE IT, and OR WHATEVER. Will sure make for lighter reading.

lvl155 1y ago

Why don’t they focus on IDE first? I still can’t use their IDE as my daily. They also need to hire someone for UI. It took me 10 minutes to figure out how to bring up their AI chat window.

Aeolun 1y ago
If it took you 10 minutes to bring that up I can’t understand why. Presumably you’ve switched to any of the other panels in Zed before?

jasonjmcghee 1y ago

Another discussion on the same topic from 3 days ago: https://news.ycombinator.com/item?id=45038710 https://news.ycombinator.com/item?id=45038710

lukaslalinsky 1y ago

I really wish Anthropic will adopt this for Claude Code, and I hope it provides at least the kind of integration they have with VS Code. Would be nice if it had access to at least diagnostics from the editor.

vlaaad 1y ago

I love this idea; I hope it gains traction. One thing that is not clear to me is file search vs unsaved files. It's common for agents to use, e.g., ripgrep to search the file system. But if the communication protocol includes read/write access to unsaved files, there is a desync in terms of accuracy.. rg can't search unsaved files.

huflungdung 1y ago

[dead]

tekacs 1y ago

It's interesting to see that there's the beginnings of an implementation for Claude Code, here: https://github.com/zed-industries/zed/blob/main/crates%2Fagent_servers%2Fsrc%2Fclaude.rs https://github.com/zed-industries/zed/blob/main/crates%2Fage... https://www.npmjs.com/package/@zed-industries/claude-code-acp https://www.npmjs.com/package/@zed-industries/claude-code-ac... Even though that doesn't seem to be mentioned on the site yet.

Eduard 1y ago

naming things isn't that hard. at least put something with AI/LLM and code/IDE in the name.

akattelu 1y ago

So much negativity in this thread. After seeing the recent demo of gemini cli working in zed, I'm actually pretty excited for standardization in this space. Helix has been my favorite editor ever since I started using it, but the lack of integrated AI features has been becoming more of a deal-breaker for me lately. Though, I can see why the maintainers are hesitant to build for it, because there hasn't been a standardized protocol. I hope ACP changes that.

rmonvfer 1y ago

I’ve been writing a tool to enable Claude Code to use ACP (because I use CC and Zed a lot) and so far I’ve been pretty successful (using the Claude Code SDK and the ACP Client library) although there are some rough edges. I will polish it a little bit and publish it tomorrow I guess.

vincelt 1y ago
Found this repo the other day in case that's useful: https://github.com/Xuanwo/acp-claude-code https://github.com/Xuanwo/acp-claude-code

upcoming-sesame 1y ago

the difference between using, for example, Gemini via ACP vs Gemini via the ide own agent is not so clear

cranberryturkey 1y ago

How's this better than MCP?

joeyguerra 1y ago

Does anyone else find it funny that LLMs need a protocol to execute tooling? Like, it understands language, right?

csomar 1y ago

I feel these solutions are approaching the problem backward. What I want is not a Claude Code in my Neovim but a Neovim in my Claude Code. That is, when the agent fails, I am able to hop in momentarily with all the perks of an IDE (ie: type-setter, LSP, etc.) and do some editing and then give control back to the agent.