Once I asked, puckishly, Claude Code to “follow the instructions in this directory” when there was only an AGENTS.md there.
In the manner of someone finding a dead mouse and holding it up for examination CC said it could find no instructions but perhaps it should check this AGENTS.md file.
Had a silly exchange with Codex: I had an AGENTS.md file in a directory that was a symlink to an already-created CLAUDE.md. On my first prompt to Codex, it decided to point to me that my AGENTS.md specifically calls out directions to Claude, and that it would generously re-interpret them as directions to itself, and that maybe I should fix my AGENTS.md to reference the correct agent.
fwiw, i am with thariq https://x.com/trq212/status/2092302273099796842 in that prompts should be tuned for models and in fact blindly applying agents.md is probably an antipattern unless you want all models to basically converge to some common ill defined of instruction following - good local minima, bad global minima for model diversity and exploration of intelligence.
aka, sometimes it really is too early to force a standard
If you want this it's trivial to add an AGENTS.md that simply says "if you're Claude read CLAUDE.md, if you're Astra read ASTRA.md". A common entry point is good regardless.
depends what you're doing. if you've got a specialized agent deployed in prod, of course your evals and prompts will be targeted towards 1 specific version of a model.
on the other hand if it's just a local coding/"use my computer" agent, i highly doubt the effort in maintaining different prompts is worth any gain in performance
No thanks, I'm not tuning a bunch of files just for things to break when I switch models or a new one comes out.
I'll just use my one-size-fits-all AGENTS.md file and tweak it when the one of the clankers screw up. I don't have time for such busywork.
Actually, I will append extra rules to CLAUDE.md (which imports AGENTS.md) since there is a hook there, and Claude has its own foibles. So I'll backpedal a bit there.
In a "one LLM only" environment, your instructions are by default tuned for said LLM.
In a multi-LLM environment, roughly nobody will keep separate sets of instructions for each. It's not a realistic take.
On top of that: If your LLM is so bad at reading that it can't follow a set of instructions that wasn't specifically written just for that one single precious LLM, I sure wonder what that says about your employers repeated statements that ASI is definitely right around the corner.
I'm honestly not sure if this is tongue in cheek and the "finally" is in the silly way it is often used, but the claude.md variant existed first. Indeed, the agents.md thing was pretty clearly a "that's neat, let's do that with a different name".
I recently had Claude Fable set up a new project for me and I pointed it at some existing projects to use as a guide on how I like to structure things. It created, unprompted, an AGENTS.md file and a CLAUDE.md symlink to AGENTS.md
I didn't even have that symlink in any other project - it just did it. I think it saw that one of the projects I already had was set up by Codex and that project had an AGENTS.md so perhaps it inferred that I was using both Claude and Codex, so it was politely covering both? Or maybe a recent change made this behavior default?
I was surprised and I hope they continue to seek standards.
Seems agents understand their own bugs now. https://github.com/openai/codex/issues/9252 has 88 thumbs up and a workaround (switch to raw mode with Alt+R) found in a comment. Codex suggested the workaround to me today when I complained about its multi-line bash command being corrupted on paste because of the two-space indent in Codex's code blocks.
> “I’m thinking about banning Claude Code at Shopify until they change their mind and read AGENTS.md and .agents/skills etc.,” Lütke posted Tuesday on X.
finally!
Now this might sound sorta off-topic but i really wonder how people feel about skills.md, skill.md, skills.sh domains...
the fact that they're owned by different companies (ok vercel is a little less random) still leaves me with a sour taste in my mouth when thinking about the fact that they should all point to 1 place about how to create and find skills for ai agents?!
Remember they didn't do this because they wanted to help community, they did it because community was angry and they were losing users to other harnesses.
Doesn't look like Anthropic care about dev community
yep, all i want is freedom to make a workflow where i don't feel tied to one provider, CC is exactly what i don't wanna get trapped in. I'll happily use claude MODELS, but if it means i have to keep learning two harnesses side by side to keep using one particular provider, then the second i can easily replace it, i am going to(even if its a small drop in performance).
This project uses `AGENTS.md` as its agent instruction file (kept provider-agnostic).
Treat any `AGENTS.md` file exactly as you would a `CLAUDE.md` file — at the root level and in any subdirectory you are working in.
On many filesystems, a lot of data about a file is not attached to the content of the file, but stored in a master filename and metadata table graph tree of some sort, and the address offset within that metadata used to retrieve the contents on disk can be a duplicate of another entry, without that situation instantly leading to a filesystem driver crash. Some filesystems officially support such duplicates as well as equivalents of HTTP 3xx, some you can just do as a matter of fact and fsck would have some words about it.
Default filesystems for all Unix, Linux, WinNT, all do.
Forcing their own proprietary filename was clearly a business decision (it's free advertising, along with commit co-authorship). I wonder what made them go back on it.
Claude also checks your settings.json first, and if it sees a default there it then prefers that over anything in CLAUDE.md. This is particularly nefarious as they ship logic to presume a default if a setting is not there in settings.json, even if there are instructions in CLAUDE.md for exactly that.
For instance, say you added "do not add 'Made with Claude Code' in any issues, pull requests or wiki entries" in your CLAUDE.md. So far, so good.
Well the latest update now looks for something in your settings.json. Since you don't know about it, it is not set. Claude then says "not explicitly set, so now it is true by default". It completely ignores your CLAUDE.md.
Wait, what?
You shouldn't be shipping logic that arbitrarily redefines the behavior of the program, especially if your new logic actually ignores your own configuration or directives.
Windows does actually have symlinks but I don't think I've ever seen anything actually use them, and I don't myself because it smells of interop issues with other windows apps.
Even to this day Windows has all kinds of problems around long file paths in its ecosystem.
> Even to this day Windows has all kinds of problems around long file paths in its ecosystem.
To this day I don't know if it's a Windows problem or a Python problem, because I never encountered this - and never realized this problem exists - except for some random Python code whose docs tell me to set some registry value because of "long paths issue".
Windows supports it but git disables creating symlinks by default.
> Short version: there is no exact equivalent for POSIX symlinks on Windows, and the closest thing is unavailable for non-admins by default unless Developer Mode is enabled and a relatively recent Windows 10 version is used. Therefore, symlink emulation support is only turned on by default when that scenario is detected. Support can be enabled by the user, via the core.symlinks=true config setting.
Can it read copilot.md if neither of the other files are present?
Also: agents should be the standard, or we need to invoke the XKCD for "one more standard to rule them all"?
Still don't understand the point of the markdown files.
Isn't it literally all just more text you're adding to the prompt. How can you even be sure it isn't just clouding context with nonsense for whatever you're asking for?
You know it because you write the content of AGENTS.md. And if you are smart, you keep it brief and cover only the important things that anyone (human OR LLM) would want to know if working in this directory.
In my experience telling it what I want is not a reliable process at all whatsoever if what I'm asking for is sufficiently complex, no matter what context I provide. So instead I break tasks down into very small parts, ask for solutions to those that I can reasonably quickly assess and then put them together myself. Asking it to do the architectural or deep algorithmic legwork IME wastes so much time and is often just wrong.
There's a balance to be found here, that's unfortunately very hard to find at times.
In my experience, there are two classes of tasks: some are very "in-distribution", and for those LLMs can near-flawlessly perform the "architectural or deep algorithmic legwork", with maybe a single second round to fix the mistakes. For others, I have to break the tasks down myself, and often it's a "death through thousand papercuts", because the size of a task that I can quickly verify and the LLM will not screw up with > 50% probability is small enough that it's sometimes net negative time spent relative to doing it myself (and using LLMs only as glorified search engine and article summarizer).
I like to tell myself that I'm getting better at recognizing these two classes up front, but I'm still frequently surprised when "type 1" turns out to be "type 2".
But circling back to the main topic: with "type 2", agent instructions are paramount, if only to enforce the "small steps, pre-commit to scope and methodology, verification at the end, user doesn't even want to know about anything in between" rules, as agents naturally want to run ahead faster than I can keep up with.
Once I asked, puckishly, Claude Code to “follow the instructions in this directory” when there was only an AGENTS.md there.
In the manner of someone finding a dead mouse and holding it up for examination CC said it could find no instructions but perhaps it should check this AGENTS.md file.
Had a silly exchange with Codex: I had an AGENTS.md file in a directory that was a symlink to an already-created CLAUDE.md. On my first prompt to Codex, it decided to point to me that my AGENTS.md specifically calls out directions to Claude, and that it would generously re-interpret them as directions to itself, and that maybe I should fix my AGENTS.md to reference the correct agent.
Very sassy, Codex!
That’s pretty funny.
Also: did it suggest instructions for the “correct” agent, or an ambiguous agent?
One has marketing implications, the other one is generally decent advice.
But if you said that you were migrating from another platform to Claude, my guess is that it would have happily found and converted AGENTS.md
Finally doing something standards-compliant instead of forcing users into a proprietary workflow.
fwiw, i am with thariq https://x.com/trq212/status/2092302273099796842 in that prompts should be tuned for models and in fact blindly applying agents.md is probably an antipattern unless you want all models to basically converge to some common ill defined of instruction following - good local minima, bad global minima for model diversity and exploration of intelligence.
aka, sometimes it really is too early to force a standard
If you want this it's trivial to add an AGENTS.md that simply says "if you're Claude read CLAUDE.md, if you're Astra read ASTRA.md". A common entry point is good regardless.
I have had very little luck with agents.md. What has worked well for me is a ./docs folder. They seem to just create and update stuff on their own.
Try naming the file "not_for_claude.md"
By this logic you'd probably be wise to tier your claude.md by model (sonnet/opus) as well as effort level too, considering the varying failure modes
depends what you're doing. if you've got a specialized agent deployed in prod, of course your evals and prompts will be targeted towards 1 specific version of a model.
on the other hand if it's just a local coding/"use my computer" agent, i highly doubt the effort in maintaining different prompts is worth any gain in performance
No thanks, I'm not tuning a bunch of files just for things to break when I switch models or a new one comes out.
I'll just use my one-size-fits-all AGENTS.md file and tweak it when the one of the clankers screw up. I don't have time for such busywork.
Actually, I will append extra rules to CLAUDE.md (which imports AGENTS.md) since there is a hook there, and Claude has its own foibles. So I'll backpedal a bit there.
Yeah but are models good enough to review these files and say “i would work better if you worded it this way?”
That's of course rather nonsensical.
In a "one LLM only" environment, your instructions are by default tuned for said LLM.
In a multi-LLM environment, roughly nobody will keep separate sets of instructions for each. It's not a realistic take.
On top of that: If your LLM is so bad at reading that it can't follow a set of instructions that wasn't specifically written just for that one single precious LLM, I sure wonder what that says about your employers repeated statements that ASI is definitely right around the corner.
CLAUDE.md: @AGENTS.md
Why not hardlink - so it wouldn't even know?
Wake up babe, new recursive self learning technique just dropped.
I tried that before, it doesn’t work. Claude will not prioritize AGENTS instructions the same way it did for CLAUDE.
ln was the only thing that worked for me
I'm honestly not sure if this is tongue in cheek and the "finally" is in the silly way it is often used, but the claude.md variant existed first. Indeed, the agents.md thing was pretty clearly a "that's neat, let's do that with a different name".
There’s also that whole MCP thing.
I recently had Claude Fable set up a new project for me and I pointed it at some existing projects to use as a guide on how I like to structure things. It created, unprompted, an AGENTS.md file and a CLAUDE.md symlink to AGENTS.md
I didn't even have that symlink in any other project - it just did it. I think it saw that one of the projects I already had was set up by Codex and that project had an AGENTS.md so perhaps it inferred that I was using both Claude and Codex, so it was politely covering both? Or maybe a recent change made this behavior default?
I was surprised and I hope they continue to seek standards.
Seems agents understand their own bugs now. https://github.com/openai/codex/issues/9252 has 88 thumbs up and a workaround (switch to raw mode with Alt+R) found in a comment. Codex suggested the workaround to me today when I complained about its multi-line bash command being corrupted on paste because of the two-space indent in Codex's code blocks.
Justba prompt change.
Caught myself about to praise this, but it's the absolute bare minimum.
Time to delete the symlinks
LOL https://thenewstack.io/shopify-claude-code-agentsmd/
> “I’m thinking about banning Claude Code at Shopify until they change their mind and read AGENTS.md and .agents/skills etc.,” Lütke posted Tuesday on X.
Don’t get too excited, Claude code still won’t detect skills on .agents/skills.
They have AGI, but they don't have $20 of token budget to add a so basic functionality.
They probably have an explicit instruction in their own CLAUDE.md to not implement that support.
Its the only explanation. I mean, they are not living under a rock...
As evidence that they actually are living under a rock, there's still no proper way to mv a workspace and have it retain all its history and config.
A post-checkout git hook can handle this unfortunate situation.
Don't worry, it's on the roadmap for Q4 2029.
I wonder when they'll finally fix the VS Code plugin to not constantly dump your current file into the context.
finally! Now this might sound sorta off-topic but i really wonder how people feel about skills.md, skill.md, skills.sh domains...
the fact that they're owned by different companies (ok vercel is a little less random) still leaves me with a sour taste in my mouth when thinking about the fact that they should all point to 1 place about how to create and find skills for ai agents?!
Finally, I can delete `sync-agent-docs.sh`, which recursively symlinked AGENTS.md to GEMINI.md and CLAUDE.md...
Remember they didn't do this because they wanted to help community, they did it because community was angry and they were losing users to other harnesses.
Doesn't look like Anthropic care about dev community
Sanity prevails
This just be a recession indicator
Still can't read what their models vomit at me.
The madlads finally did it, now if only I could use my Claude sub in other harnesses without risking getting banned.
yep, all i want is freedom to make a workflow where i don't feel tied to one provider, CC is exactly what i don't wanna get trapped in. I'll happily use claude MODELS, but if it means i have to keep learning two harnesses side by side to keep using one particular provider, then the second i can easily replace it, i am going to(even if its a small drop in performance).
My claude.md:
# CLAUDE.md
This project uses `AGENTS.md` as its agent instruction file (kept provider-agnostic). Treat any `AGENTS.md` file exactly as you would a `CLAUDE.md` file — at the root level and in any subdirectory you are working in.
@AGENTS.md
If only there was a technology that existed to link files together… /s
You mean symbolically?
Good one
The idea was to have it automatically detect nested AGENTS.md
Does your tech do that?
Anyway, the joke is on me I guess, because it might not work reliably.
On many filesystems, a lot of data about a file is not attached to the content of the file, but stored in a master filename and metadata table graph tree of some sort, and the address offset within that metadata used to retrieve the contents on disk can be a duplicate of another entry, without that situation instantly leading to a filesystem driver crash. Some filesystems officially support such duplicates as well as equivalents of HTTP 3xx, some you can just do as a matter of fact and fsck would have some words about it.
Default filesystems for all Unix, Linux, WinNT, all do.
Forcing their own proprietary filename was clearly a business decision (it's free advertising, along with commit co-authorship). I wonder what made them go back on it.
AGENTS.md is the new autoexec.bat.-
Claude also checks your settings.json first, and if it sees a default there it then prefers that over anything in CLAUDE.md. This is particularly nefarious as they ship logic to presume a default if a setting is not there in settings.json, even if there are instructions in CLAUDE.md for exactly that.
For instance, say you added "do not add 'Made with Claude Code' in any issues, pull requests or wiki entries" in your CLAUDE.md. So far, so good.
Well the latest update now looks for something in your settings.json. Since you don't know about it, it is not set. Claude then says "not explicitly set, so now it is true by default". It completely ignores your CLAUDE.md.
Wait, what?
You shouldn't be shipping logic that arbitrarily redefines the behavior of the program, especially if your new logic actually ignores your own configuration or directives.
Thanks guys, you did the right thing.
Hell froze over?
This is not a news to celebrate, they must follow standards
great, one less step for me.
I was using my claude.md file as a pointer to my agents.md file
Wow..... Progress and technical innovation right here!!!
This allows us to remove our one line Claude.md files that just say "AGENTS.MD"
ln -s AGENTS.md CLAUDE.md
Fine if you don't need to git checkout the repo on Windows :)
Just .gitignore CLAUDE.md and handle it locally. Checking in a symlink would be weird.
Wow, still not there yet. After all these years.
Windows does actually have symlinks but I don't think I've ever seen anything actually use them, and I don't myself because it smells of interop issues with other windows apps.
Even to this day Windows has all kinds of problems around long file paths in its ecosystem.
> Even to this day Windows has all kinds of problems around long file paths in its ecosystem.
To this day I don't know if it's a Windows problem or a Python problem, because I never encountered this - and never realized this problem exists - except for some random Python code whose docs tell me to set some registry value because of "long paths issue".
The worst offenders I've found are powershell and .Net related stuff.
You can have all the right flags enabled, then unexpectedly you'll run some commandlet and get a path too long error.
Now if your on W11/W25 and the lastest PS it might all work, but W16 and PS versions between now and then had all kinds of things pop up.
I'm surprised Git and/or Windows don't support symlinks?
Windows supports it but git disables creating symlinks by default.
> Short version: there is no exact equivalent for POSIX symlinks on Windows, and the closest thing is unavailable for non-admins by default unless Developer Mode is enabled and a relatively recent Windows 10 version is used. Therefore, symlink emulation support is only turned on by default when that scenario is detected. Support can be enabled by the user, via the core.symlinks=true config setting.
See: https://gitforwindows.org/symbolic-links.html
Windows does mklink. Not surprised with git.
are you though?
oh god. sorry.
Only took them a year and a half of everyone complaining to finally do the right thing.
Congrats.
Truly incredible innovation.
Can it read copilot.md if neither of the other files are present? Also: agents should be the standard, or we need to invoke the XKCD for "one more standard to rule them all"?
Ah yes, the peak of technology.
First feature to borrow after peaking into openai repos? ))
There goes their moat...
Hi, September 2026, meet September 2025
Thank you Tobi Lutke.
Context
“I’m thinking about banning Claude Code at Shopify until they change their mind and read AGENTS.md and .agents/skills etc.,”
- Tobi Lütke on X.
About time!
why did it take so long?
Still don't understand the point of the markdown files.
Isn't it literally all just more text you're adding to the prompt. How can you even be sure it isn't just clouding context with nonsense for whatever you're asking for?
You know it because you write the content of AGENTS.md. And if you are smart, you keep it brief and cover only the important things that anyone (human OR LLM) would want to know if working in this directory.
As far as I understand even adding relevant information still eventually clouds context
You still need to define assumptions somehow. What you want and what the model wants will not match up by default.
In my experience telling it what I want is not a reliable process at all whatsoever if what I'm asking for is sufficiently complex, no matter what context I provide. So instead I break tasks down into very small parts, ask for solutions to those that I can reasonably quickly assess and then put them together myself. Asking it to do the architectural or deep algorithmic legwork IME wastes so much time and is often just wrong.
There's a balance to be found here, that's unfortunately very hard to find at times.
In my experience, there are two classes of tasks: some are very "in-distribution", and for those LLMs can near-flawlessly perform the "architectural or deep algorithmic legwork", with maybe a single second round to fix the mistakes. For others, I have to break the tasks down myself, and often it's a "death through thousand papercuts", because the size of a task that I can quickly verify and the LLM will not screw up with > 50% probability is small enough that it's sometimes net negative time spent relative to doing it myself (and using LLMs only as glorified search engine and article summarizer).
I like to tell myself that I'm getting better at recognizing these two classes up front, but I'm still frequently surprised when "type 1" turns out to be "type 2".
But circling back to the main topic: with "type 2", agent instructions are paramount, if only to enforce the "small steps, pre-commit to scope and methodology, verification at the end, user doesn't even want to know about anything in between" rules, as agents naturally want to run ahead faster than I can keep up with.
do you just manually type out your important instructions every time instead of being smart and putting a few lines in a text file?
Great, now I have to redo my scaffold harness. I guess this agent.md awareness is part of the system prompt?
nope! they're releasing something called "Claude Code mods", toted as their "upcoming way to customize the Claude Code harness"
https://x.com/trq212/status/2101009392611278961
AGENTS.md implementation is open sourced as well: https://github.com/anthropics/claude-code/tree/main/mods/age...
Nice. Thanks!
Forced to do something for the users...
They have achieved AGI/RSI internally and it told them "common, let's sort this s..t out, it's embarrasing".
Great, now please standardize the skills folder and the MCP config.
A reminder that needs to be said: Don't use a closed-source harness.
Why? This is why. [0]
[0] https://news.ycombinator.com/item?id=49750694
yay! /s
Why are people still putting up with this kind of attitude, especially when there are so many good alternatives available?