Claude Code Adds Native AGENTS.md Support
Claude CodeClaude Code now reads AGENTS.md as its project-instructions file whenever a project has no CLAUDE.md, closing a long-requested gap with the cross-tool convention already used by Codex, GitHub Copilot, and Gemini CLI. The behavior is a fallback, not a merge: CLAUDE.md still takes priority wherever it already exists, so no existing setup changes. The toggle lives under "Project instructions" in /config, and the feature is not yet available on Bedrock, Vertex, or Foundry deployments.
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Key Takeaways
- AGENTS.md is now a genuine fallback, read automatically whenever a project has no CLAUDE.md.
- CLAUDE.md still wins, so existing Claude Code projects with a CLAUDE.md file see no behavior change at all.
- The toggle lives in
/config, under "Project instructions," letting teams turn the fallback off if they want CLAUDE.md-only behavior. - Enterprise platforms lag behind: Bedrock, Vertex AI, and Foundry deployments do not get AGENTS.md support in this release.
- The move formally aligns Claude Code with the cross-tool convention already used by Codex, GitHub Copilot, and Gemini CLI, reducing the need to maintain duplicate instruction files.
- The announcement generated one of the larger Hacker News threads of the week (609 points), reflecting how widely developers had wanted this specific gap closed.
Sources & Mentions
4 external resources covering this update
What changed
Version 2.1.277, released September 18, 2026, added AGENTS.md support to Claude Code. In a project that has no CLAUDE.md file, Claude Code now reads AGENTS.md instead of falling back to no project instructions at all. The setting can be changed under "Project instructions" in /config. The feature is not yet available on Amazon Bedrock, Google Vertex AI, or Microsoft Foundry deployments.
Why it matters
AGENTS.md has emerged as a cross-tool convention for briefing AI coding agents on project context, conventions, and operating rules, already supported by OpenAI Codex, GitHub Copilot, and Gemini CLI, among others. Teams that use more than one coding agent previously had to maintain Claude Code's proprietary CLAUDE.md alongside a separate AGENTS.md, or resort to symlinks and manual imports to keep both in sync. With this release, a single AGENTS.md file can serve as the baseline instruction set for Claude Code as well, as long as no CLAUDE.md is already present in that project.
How it behaves
The support is additive, not a replacement: CLAUDE.md keeps priority in any repository that already has one, so nothing changes for existing Claude Code setups. AGENTS.md is only consulted as a fallback in projects with no CLAUDE.md. Developers can toggle the behavior from the "Project instructions" section of /config.
Reception
The change drew a large Hacker News discussion (609 points), with much of the community welcoming the move as overdue standardization, while some commenters noted how long the request had been open before Anthropic implemented it.