Anthropic adds AGENTS.md support to Claude Code
Claude now reads AGENTS.md files to customize code assistant behavior, rolling out in version 2.1.277.
What to know
- Claude Code now supports AGENTS.md files for customizing code assistant behavior, rolling out in version 2.1.277.
- The feature builds on Claude Code mods, a new framework for creating custom modifications to the code harness.
- Users can toggle AGENTS.md support in /config settings.
“AGENTS.md support is built off of Claude Code mods, our upcoming way to customize the Claude Code harness.”
Thariq Shihipar, Anthropic engineer · Simon Willison blog ↗ · Sep 17
Thariq Shihipar Anthropic engineerAnthropic AI company
How it unfolded 0 developments, newest first · click a bar or a number to jump
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background
Anthropic rolls out AGENTS.md support in Claude Code 2.1.277 — Claude Code now includes support for AGENTS.md files as a fallback when CLAUDE.md is not present in a folder. The feature is built on Claude Code mods, an upcoming customization system for the code assistant harness. Users can toggle the behavior in /config.
What people are saying 23 voices from 3 sites · best of 61 · verbatim
- Yesterday
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Hey, it seems you work there. I had a tangential question. Did any Anthropic exec threaten to do something unsavoury if any engineer ever tried to not name the claude cli binary as the version number itself? Because if they did, I'd understand. Or if you dare change it all the vibe-coded ts/react/etc dominoes will go for a fall in unison? I'd…
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I can understand honest mistakes, but like, usually when I develop anything with agents (which I assume is what you're doing internally at Anthropic), they're almost too enthusiastic about trying to add test cases to the point where they sometimes try to glue together things in ways that are structurally impossible in the actual code in order to…
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I don’t understand why people are confused about the use of a launch flag, for this and for anything.It’s a simple distributed systems problem. Separate the deployment of a new software feature (to umpteen hosts) from the triggering of that software with a lightweight switch.If someone think that reading AGENTS.md is always benign, because they…
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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…
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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.If folks play around with it, I would love feedback on the relevant issue: https://github.com/anthropics/claude-code/issues/91870Mods allow quite a bit…
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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…
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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 mod is source available here: https://github.com/anthropics/claude-code/tree/main/mods/age...Apologies again folks…
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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…
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Isn't that how they just release all features? So they can do progressive roll outs and telemetry on issues with 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…
- Sep 19
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I couldn't care less what the filename is, I do care however that Claude still forgets about 14 times per week that -r with ripgrep means replace (and not recursive, like with grep). Even though it's literally spelled out in my CLAUDE.md. Claude code, even with the most advanced models, forgets or disregards very simple and clear instructions from…
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I switched to oh-my-py and never looked back. I guess having an incentive to maximize (expensive) token usage, and LLMs degrading with higher context, isn't aligned with a user's best interest.Oh-my-py unlocks max capabilities at the smartest token usage, and you can change AI company and providers while still getting things done. Roles, advisor…
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Claude Code wraps both the AGENTS.md and CLAUDE.md in a system-reminder with this disclaimer at the bottom:IMPORTANT: this context may or may not be relevant to your tasks. You should not respond to this context unless it is highly relevant to your task.Codex follows the AGENTS.md far better. CC seems to have nudged people away from taking the…
- Sep 18
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W
Long live AGENTS.md. I guess. https:// code.claude.com/docs/en/change log
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I suppose it’s reflective of where the industry is. Claude is just that ubiquitous.Reminds me of when you’d see posts for React 16.0.3 or whatever. Absolutely minor news, but multiply that by the number of users…Now I just need to figure out which one makes me feel worse.
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Meanwhile, I just setup codex for the first time (to try Astra) and it offered to load my Claude and Cursor conversations and claims to even do it in a way where it says in sync if you use both. The only reason to use Claude Code is the 20x usage of the 200$ plan is ridiculous value if you have the need for that volume.
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Gotta say, it is hilarious that this is the current top HN post. I feel like it's gotta say something about our current AI zeitgeist, that there is such vigorous attention on a seemingly-minor change. Feels like something is on the tip of my tongue but I can't name it at the moment.If anyone wants to write/link a much better-thought-out post, I'm…
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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…
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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.
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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…
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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.
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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.
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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.mdI didn't even have that symlink in any other project - it just did it. I think it saw that one of the projects I…
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We're adding support for AGENTS.md to Claude Code. Starting today in version 2.1.277, if there is no CLAUDE.md in a folder, Claude will check for and use AGENTS.md. You can toggle this behavior in /config.