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
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.
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.
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).
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.
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.
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"?
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.
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.
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.
Very sassy, Codex!
aka, sometimes it really is too early to force a standard
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
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.
ln was the only thing that worked for me
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.
Time to delete the symlinks
> “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.
Doesn't look like Anthropic care about dev community
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.
I was using my claude.md file as a pointer to my agents.md file
# 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
Does your tech do that?
Anyway, the joke is on me I guess, because it might not work reliably.
Default filesystems for all Unix, Linux, WinNT, all do.
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".
> 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
Congrats.
“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.
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?
https://x.com/trq212/status/2101009392611278961
AGENTS.md implementation is open sourced as well: https://github.com/anthropics/claude-code/tree/main/mods/age...
Why? This is why. [0]
[0] https://news.ycombinator.com/item?id=49750694
Why are people still putting up with this kind of attitude, especially when there are so many good alternatives available?