Claude Code 2.1.277 added native support for repository instructions in AGENTS.md. The feature has a consequential limit: Anthropic's current documentation says sessions that cannot fetch feature flags, including sessions with telemetry disabled and many third-party-provider setups, load CLAUDE.md only.

The released agents-md plugin separates file loading from its optional telemetry rows. Those rows contain counts and fixed choices and omit paths and file text. The dependency sits one layer earlier, where a remote flag decides whether the built-in loader is available.

The big change

  • What changed: A local instruction file now crosses a remote rollout boundary: feature-flag access determines whether Claude Code's built-in AGENTS.md reader is available.
  • Why it matters: Two developers on the same commit can receive different project instructions because their version, provider or privacy settings differ, making agent behavior harder to reproduce across a team.
  • What to watch: Teams using several providers or locked-down environments can treat instruction loading as a runtime dependency, verify it in each setup and keep a CLAUDE.md import as the portable path.

What the release and report establish

Anthropic's 2.1.277 release notes, dated September 18, say Claude Code reads AGENTS.md when a project has no CLAUDE.md. The notes also exclude Bedrock, Vertex and Foundry from that release.

The current project-memory documentation also excludes the first session after installing or upgrading to a supporting version, and sessions with the built-in plugin disabled.

Przemek Szypowski's triggering report describes a canary test on 2.1.280. He reports that DISABLE_TELEMETRY and CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC prevented his AGENTS.md from loading, while an adjacent CLAUDE.md import worked. BIG CHANGE did not reproduce that paid model test. Anthropic's documentation now independently states the same availability conditions.

Feature availability and telemetry logging are separate

Anthropic's environment-variable documentation says any non-empty DISABLE_TELEMETRY value, including 0 or false, opts out of telemetry and disables feature-flag fetching. DO_NOT_TRACK, DISABLE_GROWTHBOOK and CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC can also stop that fetch. Third-party-provider sessions are excluded unless an embedding host sets CLAUDE_CODE_PROVIDER_MANAGED_BY_HOST; Claude apps gateway sessions are also excluded.

The released plugin README says missing telemetry calls are dropped without changing the plugin's other work. The repository's mods overview identifies telemetry and agents-md as separate built-ins.

The source describes an operating loader; the product documentation describes whether a session gets that loader. Optional logging inside the module does not remove the availability condition outside it.

On September 23, BIG CHANGE fetched the agents-md README and registration module from both main and the 2.1.280 tag, released September 22; each pair was byte-identical.

When Claude Code loads the file

For an available, enabled plugin, the default mode follows this precedence:

Instruction files

Default result

AGENTS.md, no project Claude instruction file

AGENTS.md loads

Project CLAUDE.md, .claude/CLAUDE.md or CLAUDE.local.md in the working directory or above

Direct AGENTS.md loading yields to those files

User or managed CLAUDE.md, or .claude/rules/

These do not displace AGENTS.md

Change Project instructions in /config to load both file types. Its JSON option belongs in user, --settings or managed settings; project and local settings files are ignored.

The fallback is one explicit import

For sessions without direct support, Anthropic recommends a CLAUDE.md beside the shared file containing:

@AGENTS.md

The import includes the file; prose asking Claude to read it leaves that choice to the model.

Check claude --version and Project instructions in /config. In 2.1.280, /memory or /context can list a directly loaded AGENTS.md; earlier supporting versions did not list it there.