Add support for `AGENTS.md` file

[OskarStark]

Description

Currently, Claude Code does not support the AGENTS.md file format, while other AI coding assistants like GitHub Copilot have already implemented support for this standard. The AGENTS.md file allows developers to provide custom instructions specific to AI agents working on their codebase.

Context

AGENTS.md is becoming a standard way to provide repository-specific instructions to AI coding assistants. It allows developers to:

• Define project-specific coding standards and conventions
• Specify testing requirements and patterns
• Document architectural decisions that AI assistants should follow
• Provide context about the codebase structure and patterns

References

• AGENTS.md Specification
• Blog post about AGENTS.md
• GitHub Copilot Support Announcement

Current Behavior

Claude Code currently only supports:

• CLAUDE.md files (both global ~/.claude/CLAUDE.md and project-specific)
• No support for the standardized AGENTS.md format yet

Expected Behavior

Claude Code should:

1. Check for and read AGENTS.md file in the project root
2. Apply the instructions from AGENTS.md alongside or instead of CLAUDE.md
3. Follow the AGENTS.md specification for parsing and applying instructions

Benefits

• Interoperability: Projects using AGENTS.md would work seamlessly with Claude Code without needing duplicate configuration files
• Standardization: Following the emerging standard would benefit the entire AI coding assistant ecosystem
• Developer Experience: Developers wouldn't need to maintain multiple instruction files for different AI assistants

Proposed Implementation

Consider supporting both AGENTS.md and CLAUDE.md with a precedence order:

1. Check for AGENTS.md first (standard format)
2. Fall back to CLAUDE.md if AGENTS.md is not present
3. Potentially merge instructions if both files exist

[aszenz]

Maybe claude.md can be a sym link to agents.md

[OskarStark]

Read about this, but this will not work if other files are imported inside the CLAUDE.md file, so better wait. IMHO Claude will soon support AGENTS.md