Sorry folks, this is a rollout artifact, we needed a way to turn this off remotely via feature flags if it broke something, and with telemetry off you don't get those. It's already been fixed as part of v2.1.281 releasing today.
The AGENTS.md support was implemented via our new extensibility system for CC, called Mods, which is launching soon-ish. A mod is a plugin with a new type of hook, which we call a function hook.
The only difference between CLAUDE.md and AGENTS.md is the filename. Do you really need a whole plugin system to support that use case? Feels like this could have been a one line change.
Don't you run bizantine ralph loops on remote environments with codex security checks, coupled with jev, grok, open router and a fully independent openclaw (on a maxed out mac mini inside a caveau in an undisclosed location, with open telegram) to change constants? You're going to be left behind.
The plugin system itself was probably already in the making, and they just chose to implement this tiny feature as a plugin to try it out.
As for the only difference being the file name, that's an untested assumption. Up until now, Claude hadn't supported AGENTS.md, and it's a simple application of Hyrum's Law that somebody, somewhere, was taking advantage of that to give one set of instructions to Claude, and a different set of instructions to some other provider. The correct behaviour in the presence of both files is not obvious, either.
Having a kill switch for the change is a perfectly reasonable safety measure in case something goes horribly wrong.
> somebody, somewhere, was taking advantage of that to give one set of instructions to Claude, and a different set of instructions to some other provider.
I'm this person! I am actively doing this! I have some instructions which the Claude models need and OpenAI models do automatically (and if the OpenAI models see the Claude instructions, they will go way overboard which I don't want).
Mind, the change does not affect me at all, because when both instructions are present Claude continues to read CLAUDE.md and Codex continues to read AGENTS.md.
> Having a kill switch for the change is a perfectly reasonable safety measure in case something goes horribly wrong.
What, exactly, is going to go horribly wrong here ...? The worst case you're proposing is that an Anthropic model acts on AGENTS.md rather than CLAUDE.md. It's not going to be the end of the world; at worst it'll be `git reset --hard HEAD` time. But this wouldn't happen, because:
> The correct behaviour in the presence of both files is not obvious, either.
It seems extremely obvious to me: the non-breaking change is the right change here. If both exist, Anthropic models continue to use CLAUDE.md and ignore AGENTS.md. This is not rocket science. Why are we overthinking this?
How, exactly, would the proposed solution (combined with a setting to disable it) break, and how would implementing it the way Anthropic did address that? Be specific.
Some people might have a different CLAUDE.md and AGENTS.md because they use Claude to do one thing and $other_agent to do another thing. Or because Claude does XYZ by default, and other agents do ABC, and they want to give the correct guidance to both.
This is, to me, a completely reasonable and believable use case that could break if you implement this fix without "overengineering" it.
A setting to disable what? Be specific. See? Not so simple...
> The only difference between CLAUDE.md and AGENTS.md is the filename. Do you really need a whole plugin system to support that use case? Feels like this could have been a one line change.
I don't think this is a reasonable assumption. The document format in CLAUDE.md is whatever Anthropic specifies, where AGENTS.md is a common ground format that is expected to be supported by any agent, be it from Anthropic or not.
I think you're giving these files too much credit. There are no specs, they are freeform text. In this sense they are the same. The expectation of what could be in it by each vendor means nothing unless it's enforced.
There is no "specification", it's literally just a text file that gets loaded into context. You don't even need to write markdown. It's not that hard man.
Really loved this Tibo-level responsiveness, if Anthropic can keep it up with this level of service, I am pretty sure a lot of people will just ditch their ChatGPT subscription and just move to Claude.
On the other hand, if Anthropic is to follow the industry standards, this would never have happened in the first place. It's not like the feature gates are the frontier of software development.
What we need is a low level but constant drumbeat against openai in general. In general the AI situation is overleveraged and underpoliced, with the occasional hints of AI gone wild. If openai were to just be left to die, we could let that financial mess unroll and bail out the leftovers, I don't like bailouts anymore than the next guy but with this administration its almost a guarantee if things go south because this adminstration can charge administrative fees of maybe $20-30 billion (which goes to trump), get Sam Altman to serve one or two years in a cushy resort type fed place for the hugging face hacking and put openai's processes on github as a premium feature, say $10000 a month to access (which again goes to trump).
I know I know, why are we giving money to trump? Its because he's going to take it anyways so can't we at least apply some window dressing?
I don't think "bug" is the correct term. They put a feature behind a feature flag, and feature flags don't work if you turn them off (via telemetry). That's "Working As Designed™".
It's clearly an unintended interaction. Nobody intended for the telemetry switch to control whether it reads AGENTS.md. Whether you consider that to be a "bug" or not really wasn't the point of my message.
Based on my experience with these tools so far, this seems exactly the kind of subtle but extremely severe bug that sneaks in when you start piling up layers of AI generated patches to a codebase without caring too much about the code.
"extremely severe" - aren't we laying it on a bit thick here? The whole impact seems to be that users who have telemetry turned off got this feature ~2 days later, when the bug was noticed.
a "feature" that every user has asked for - which is the equivalent of changing claude.md to agents.md - and the release isn't even smooth because the telemetry isn't wired up quite right.
for an organization that is being used as a model for new agentic software development practices.... and every software exec on earth is trying to reshape their organizations after - its a pretty stupid bug for a feature that should've been straightforward in the first place + took forever for them to get around to.
its just kind of emblamatic of the rough edges that exist EVEN FOR SIMPLE THINGS whenever human judgement is totally removed the equation.
Yep, especially with long contexts (and moreso if the last thing you were working on in the same context involved telemetry too). AI sneaks in weird conditions like this and then does the entire "You're absolutely right" thing if you're paying enough attention to catch it.
I used to actively use Msty for local models because it just worked and had a lot of nice advanced features. A few months ago they released their beta version of a Claw-like UI and mentioned using a version of it to develop Msty itself. Well, that was around the time I stopped using Msty because every update started breaking things and two updates in a row included bugs which wiped all my configs, chats, and history.
> It seems to be exactly the opposite, a "fully human error"
"LLMize the succeses, humanize the failures." is the PR strategy at play here. Anything goes well it's because AI did it, anything goes bad it's because a human didn't catch it.
It's been like this at least months. I turned telemetry off a few months ago and it basically prevented all stages rollouts of new features from working.
Anthropic commonly gates behind feature flags that require telemetry until they're "promoted" and defaulted on.
A little bit annoying you can't manually control the flags without telemetry but I think the title is a bit click bait.
Claude Code also doesn't read AGENTS.md by default if there's a CLAUDE.md it can read instead. This isn't limited to your repo, e.g. if you have a ~/CLAUDE.md then no AGENTS.md will be read.
To always read both, you have to switch the 'Project instructions' setting to the non-default `claude-md-and-agents-md`.
Just in case anyone is wondering why their AGENTS.md still isn't being read.
This in some way sounds like VSCode's bug of always adding Copilot as a co-author of git commit regardless of user settings.
If people only glance over the code agents generate for them and don't bother to spend even half a minute thinking through what's actually happening, this is inevitable.
Certainly this kind of things happened before LLMs existed. But I'm not optimistic about the direction of how things are going.
I like to give my graces to people and the companies who are typically not trillions of dollars. Have an incredible amount of resources that many countries would like to have, with fewer of the obligations. I'm going to chalk this up to its intended
I use cursor and claude, its kinda annoying having to have the same skills in both so I made a ~/.agents/skills folder then ln both cursor and claude skills to point to that folder.
which works except that claude uses .skills/synced which is uses to sync changes to skills from claude servers into the skills folder.
every other agent I have used just directly syncs into .skills so it ends up duplicating skills
Even if this was an honest rollout mistake, the design is indefensible. Reading a local file should never depend on a remote feature flag, and silently skipping it with no warning is worse. I've tried to give Claude Code the benefit of the doubt, but this crosses a line.
I'm not the person you replied to, but your response misses their point: rollout issue aside, the approach is flawed by design. The feature author didn't address that at all.
Nice find, though I'd rather read the prompt that was used to write this article. It is about ten times longer than it needs to and is quite painful to read.
Uhm I turned off everything there is to turn off in my Pro plan, and Claude just read my agents.md with no issue? So... What telemetry am I missing? Or did they JUST update? (I updated my docker image 40 minutes ago to get Opus 5.5, am on version 2.1.280, so not the mentioned 2.1.277, so it's fixed?)
The number of people raw-dogging software that executes arbitrary instructions on their machine coming from a 3rd party server just absolutely baffles me.
The same people who've spent years of their career making sure that never happens.
Forgive me if I'm missing something really obvious, we'll blame it on lack of sleep... but is that actually the full source to Claude Code? I'm looking at the repository and I only see source for plugins, mods and scripts. When I get to the readme, it says:
"This repository includes several Claude Code plugins that extend functionality with custom commands and agents. See the plugins directory for detailed documentation on available plugins."
But I'm not a TypeScript guy, so I concede I might be missing something incredibly obvious. I remember there was a leak of the Claude Code source code at one point, and people vibe coding conversions to other languages from the leak, but I don't think the Claude Code harness itself is open source or even source available.
It's not open source. It's more "source available", since it's published, but you legally can't do anything with it. Other than maybe build it yourself, for yourself, I guess.
The mod is source available here: https://github.com/anthropics/claude-code/tree/main/mods/age...
Apologies again folks, this was a fully human error on my part - I should've found a better way to launch with a kill-switch.
If folks play around with it, I would love feedback on the relevant issue: https://github.com/anthropics/claude-code/issues/91870
Mods allow quite a bit more customizability and control. I really believe in the idea.
As for the only difference being the file name, that's an untested assumption. Up until now, Claude hadn't supported AGENTS.md, and it's a simple application of Hyrum's Law that somebody, somewhere, was taking advantage of that to give one set of instructions to Claude, and a different set of instructions to some other provider. The correct behaviour in the presence of both files is not obvious, either.
Having a kill switch for the change is a perfectly reasonable safety measure in case something goes horribly wrong.
I'm this person! I am actively doing this! I have some instructions which the Claude models need and OpenAI models do automatically (and if the OpenAI models see the Claude instructions, they will go way overboard which I don't want).
Mind, the change does not affect me at all, because when both instructions are present Claude continues to read CLAUDE.md and Codex continues to read AGENTS.md.
What, exactly, is going to go horribly wrong here ...? The worst case you're proposing is that an Anthropic model acts on AGENTS.md rather than CLAUDE.md. It's not going to be the end of the world; at worst it'll be `git reset --hard HEAD` time. But this wouldn't happen, because:
> The correct behaviour in the presence of both files is not obvious, either.
It seems extremely obvious to me: the non-breaking change is the right change here. If both exist, Anthropic models continue to use CLAUDE.md and ignore AGENTS.md. This is not rocket science. Why are we overthinking this?
Read CLAUDE.md if it doesn't exist read AGENTS.md you don't need to overthink it so much.
And I say this as someone that loves the Unix philosophy dearly.
This is, to me, a completely reasonable and believable use case that could break if you implement this fix without "overengineering" it.
A setting to disable what? Be specific. See? Not so simple...
Vibe-coding gotta vibe-code.
I don't think this is a reasonable assumption. The document format in CLAUDE.md is whatever Anthropic specifies, where AGENTS.md is a common ground format that is expected to be supported by any agent, be it from Anthropic or not.
https://agents.md/
You might argue that differences are small or negligible, but that is just an expectation.
There is no rhyme or reason to the structure of this file, just like with most things in AI. It's best effort human language.
Q: Do Anthropic actually specify a document format?
Blink twice if you need help
Does that apply to WSL? I would assume everyone develops on WSL these days if they have to use Windows, at least...
I know I know, why are we giving money to trump? Its because he's going to take it anyways so can't we at least apply some window dressing?
At least make an argument for switching vendors based on the quality or price of their service.
After the last month or so in the Codex app, I was pleased with the Claude app.
It might be a case of the grass always being greener on the other side, but this is what stands out:
After 3-4 hours of usage, the weekly usage limit moved by only 1%.
Compared to Astra where I can watch the limit draining live, this is a great improvement.
I'd estimate it 3x cheaper, and that's with a 450k context limit instead of the 258k in Codex.
So far Opus 5.5 appears less prone to stopping for no apparent reason at checkpoints in the middle of a longer task.
It doesn't open an internal browser with a useless comparison page, where it then proceeds to add notes despite no one having asked for it.
It is a breath of fresh air: I get the response in the chat, while the Codex app recently loves randomly opening artifacts instead.
Opus 5.5 xhigh made great progress on the task, more so than Astra High, but that could be random chance.
Oh, and the 'Auto' mode actually works and does not force me to instead run 'Full access' like in the Codex app, lest it blocks even 'git push'.
I've had to send such messages, but internally at work, not on HN!
Have a great day, human.
Would be interesting to know how much time you/your team spent on that design decision
for an organization that is being used as a model for new agentic software development practices.... and every software exec on earth is trying to reshape their organizations after - its a pretty stupid bug for a feature that should've been straightforward in the first place + took forever for them to get around to.
its just kind of emblamatic of the rough edges that exist EVEN FOR SIMPLE THINGS whenever human judgement is totally removed the equation.
https://news.ycombinator.com/item?id=49815363
Nothing to do with AI patches at all, nor was it a bug. It was intentional human behavior, a temporary rollout setting, that seems to have made sense.
But I guess that doesn't fit the "narrative".
"LLMize the succeses, humanize the failures." is the PR strategy at play here. Anything goes well it's because AI did it, anything goes bad it's because a human didn't catch it.
No matter what happens to be the truth, HNers have a cynical narrative to fit it.
Not sure if they later move the code from inside the flag check to the main code or that they keep the flag check.
But if they would keep all features behind a flag that would not make most sense as you then would have not many features without telemetry.
> Added AGENTS.md support: in a project with no CLAUDE.md, Claude Code reads AGENTS.md instead
My dumb brain tells me none of this is rolled out progressively (as of that version). You either have it or not.
Anthropic commonly gates behind feature flags that require telemetry until they're "promoted" and defaulted on.
A little bit annoying you can't manually control the flags without telemetry but I think the title is a bit click bait.
To always read both, you have to switch the 'Project instructions' setting to the non-default `claude-md-and-agents-md`.
Just in case anyone is wondering why their AGENTS.md still isn't being read.
If people only glance over the code agents generate for them and don't bother to spend even half a minute thinking through what's actually happening, this is inevitable.
Certainly this kind of things happened before LLMs existed. But I'm not optimistic about the direction of how things are going.
Not sure what y’all are thinking with these unwritten conspiracy theories that begin and end with “it’s intentional”
https://www.thatprivacyguy.com/blog/anthropic-spyware/
+ not letting users change their email, or remove their payment methods, etc.
which works except that claude uses .skills/synced which is uses to sync changes to skills from claude servers into the skills folder.
every other agent I have used just directly syncs into .skills so it ends up duplicating skills
@agents.md
The same people who've spent years of their career making sure that never happens.
[0] https://news.ycombinator.com/item?id=49760449
So I am unsure if it is fitting to call it a "closed source" harness.
[0] https://github.com/anthropics/claude-code
"This repository includes several Claude Code plugins that extend functionality with custom commands and agents. See the plugins directory for detailed documentation on available plugins."
But I'm not a TypeScript guy, so I concede I might be missing something incredibly obvious. I remember there was a leak of the Claude Code source code at one point, and people vibe coding conversions to other languages from the leak, but I don't think the Claude Code harness itself is open source or even source available.
AGI was reached like 2 weeks ago, latest claude 5.x models rule supreme and oftware engineering is solved?
claude-md-or-agents-md
claude-md-and-agents-md