The news

Primaries: Claude Code CHANGELOG entry for 2.1.277, and How Claude remembers your project.

Changelog line: "Added AGENTS.md support: in a project with no CLAUDE.md, Claude Code reads AGENTS.md instead; change it under "Project instructions" in /config (not yet on Bedrock, Vertex or Foundry)."

Docs add the operator detail: by default Claude reads AGENTS.md only when no CLAUDE.md, .claude/CLAUDE.md, or CLAUDE.local.md sits in the working directory or above it. User-level and managed CLAUDE.md files do not block AGENTS.md. /config can set claude-md-and-agents-md, claude-md, or managed-only.

Why it matters

Repos that standardized on AGENTS.md for Codex, Cursor, Copilot, Gemini CLI, and others no longer need a second instruction file solely for Claude Code on supported sessions. CLAUDE.md remains the native format and still wins when present.

What to do now

  • On 2.1.277+: run /config → Project instructions if you want both files loaded.
  • If you keep a personal CLAUDE.local.md in an AGENTS.md-only repo, know it suppresses AGENTS.md under the default. Switch to claude-md-and-agents-md or import @AGENTS.md from CLAUDE.md.
  • Bedrock, Vertex, Foundry, or telemetry-disabled sessions: treat direct AGENTS.md load as unavailable; keep an @AGENTS.md import in CLAUDE.md.
  • Confirm with the startup line AGENTS.md loaded: … or by asking the session what project instructions it has. Direct AGENTS.md loads do not appear in /memory the way CLAUDE.md does.

Caveats

First session after upgrade may not load AGENTS.md until the next session, per docs. disableAllHooks / managed-hooks-only / disabling the built-in agents-md plugin also removes support.