Anthropic Fixes Claude Code's Silent AGENTS.md Gate

Claude Code stopped silently skipping a project's AGENTS.md file on Wednesday, when Anthropic shipped version 2.1.281 five days after developers on GitHub and Hacker News worked out why the tool's newest feature was not doing anything for them.

Anthropic added AGENTS.md support to Claude Code 2.1.277 on Sept. 18. Thariq Shihipar, a member of technical staff at Anthropic working on Claude Code, said the tool would check for an AGENTS.md file whenever a working directory had no CLAUDE.md of its own, letting a project keep one instruction file for several coding agents instead of duplicating it. DevOps.com reported that the AGENTS.md format was already used across more than 60,000 open-source projects and more than 30 compatible tools before Claude Code added support.

The feature ships with four settings reachable through /config: claude-md-or-agents-md, the default, which falls back to AGENTS.md only where no CLAUDE.md exists; claude-md-and-agents-md, which loads both; claude-md, which ignores AGENTS.md entirely; and managed-only, which drops project-level instruction files altogether, according to the README Anthropic published alongside the change.

Where the check silently failed

Developer Przemek Szypowicz, who writes at blog.szypowi.cz, found that Claude Code's AGENTS.md loader depended on a Statsig remote flag named tengu_agents_md_mod, which defaults to false and needs a live connection to Anthropic's servers to resolve. He tested it with a canary phrase placed in an AGENTS.md file and confirmed the file went unread whenever that connection was unavailable, with no warning printed to the terminal.

Setting or environment	AGENTS.md loads?
Default install, telemetry on	Yes
CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1 set	No
Telemetry disabled by any method	No
Bedrock, Vertex or Foundry	No
First session after install or upgrade	No

A GitHub user who filed issue 95690 against the anthropics/claude-code repository on Sept. 20 wrote that Claude had modified files without being told the instructions in AGENTS.md existed, since the tool gave no indication the file had been skipped. A second developer, GitHub user mmailhos, confirmed in the same thread that AGENTS.md was skipped on version 2.1.278 both in the first session after a fresh install and in every later session where feature-flag fetching was disabled.

What Anthropic said once developers noticed

A commenter posting as mpoteat, who described having built AGENTS.md support through a new Claude Code plugin system called Mods, replied on the Hacker News thread about the issue: "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." In a follow-up comment the same day, mpoteat added, "this was a fully human error on my part - I should've found a better way to launch with a kill-switch."

As of Wednesday afternoon, Claude Code's own public changelog file still topped out at version 2.1.280 and made no mention of the AGENTS.md flag or its fix, leaving the Hacker News comment as the only place Anthropic had put the explanation on the record. Mods, the plugin system mpoteat credited with making AGENTS.md support possible, has not shipped publicly yet; a cache-key requirement OpenAI dropped from GPT-6 this month shows the same kind of default behavior change landing with no advance notice to developers who depend on it.

The episode is the second time this month Anthropic has walked back a shipped feature within days, after the company pulled Claude for Financial Advisors a week after launch. Anthropic has not said whether the Mods system that produced the AGENTS.md gate will get a public release date before more features ship behind it.