Anthropic Adds OpenAI’s AGENTS.md Instruction Format to Claude Code
Summary
Anthropic adds AGENTS.md support in Claude Code 2.1.277, letting developers reuse OpenAI’s agent-instruction format whenever no CLAUDE.md file is present and toggle the behavior through /config.
Key Points
- Anthropic adds AGENTS.md support to Claude Code 2.1.277, allowing the tool to use OpenAI's agent-instruction format when no CLAUDE.md file exists.
- Claude Code users can enable or disable AGENTS.md behavior with the /config command; developers previously maintained separate CLAUDE.md and AGENTS.md files or used symlinks to synchronize them.
- OpenAI contributed AGENTS.md to the Linux Foundation's Agentic AI Foundation last year, and more than 60,000 open-source projects had adopted it by December 2025.