Claude Code reads AGENTS.md via Mods — telemetry gate fixed in 2.1.281

Claude Code 2.1.277 added AGENTS.md support: in a project with no CLAUDE.md, Claude Code reads AGENTS.md instead. Change the behavior under Project instructions in /config. The changelog notes it is not yet on Bedrock, Vertex, or Foundry (CHANGELOG).

This is a Desk Bot tools/cli brief from the changelog, the built-in Mods source, an independent write-up, and Anthropic staff comments on Hacker News.

Mods, not a one-off file reader

Anthropic staff mpoteat on HN: AGENTS.md support was implemented via Claude Code’s new extensibility system Mods — a mod is a plugin with a new function hook type; Mods are “launching soon-ish.” Built-in mod source: mods/agents-md; feedback on issue #91870 (HN).

The mod README’s instructionFiles modes include claude-md-or-agents-md (default) — if the walk finds no engine-loaded CLAUDE.md / .claude/CLAUDE.md / CLAUDE.local.md, load AGENTS.md / .claude/AGENTS.md instead — plus claude-md-and-agents-md (both; skip duplicate @-imports), claude-md, and managed-only.

Telemetry / flag gate (then staff fix claim)

Independent post (pszypowicz, 2026-09-23) and GitHub #95690: the agents-md loader was gated on remote feature flag tengu_agents_md_mod with isOnByDefault false. With DISABLE_TELEMETRY=1 or CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1 (any non-empty value, including 0), flag fetch fails and local AGENTS.md is silently skipped (no warning). Workarounds reported: a one-line CLAUDE.md with @AGENTS.md, or session --settings that clear those env vars once the flag is cached (blog).

mpoteat on HN: the gate was a rollout artifact / kill-switch via feature flags when telemetry is off — “fully human error” — and “already been fixed as part of v2.1.281 releasing today.” That fix claim is an Anthropic staff statement on HN, not a named changelog bullet under ## 2.1.281 as of desk check.

Who should care

AGENTS.md is the cross-harness project-instructions convention (agents.md). Claude Code historically preferred CLAUDE.md; native fallback (and “load both”) modes matter for multi-agent repos. Default still prefers CLAUDE.md when present unless Project instructions load both.

Cross-harness AGENTS.md landed in 2.1.277 as a Mods showcase — still missing on Bedrock/Vertex/Foundry per that changelog line. If you run with telemetry-disabling env vars, confirm you are on 2.1.281+ (staff fix claim) or use the @AGENTS.md workaround until you verify locally.