Running Claude Code next to Codex? Claude skips AGENTS.md when a CLAUDE.md exists, so import it with @AGENTS.md

#What changed

Claude Code (v2.1.277 and later) can read a repo's AGENTS.md, the instruction file Codex uses, as its project instructions. Anthropic's docs say the default is either/or: if a CLAUDE.md, .claude/CLAUDE.md, or CLAUDE.local.md exists in your working directory or above it, Claude reads those and skips AGENTS.md. @torfinpd reports that in 161 of 283 popular repos that ship an AGENTS.md, a CLAUDE.md also exists, so Claude never opens the shared file there. @LewisTenders adds that Claude still doesn't read the .agents/skills folder Codex uses.

#Who is affected

Anyone running Claude Code and Codex on the same repo, especially repos that have both files. Adding a CLAUDE.local.md for personal notes also counts and quietly turns AGENTS.md off.

#What to do now

1. Keep AGENTS.md as the single source. Put @AGENTS.md on the first line of CLAUDE.md, then add any Claude-only notes below it.
2. Or, to have Claude read both files automatically, run /config and set Project instructions to claude-md-and-agents-md. An AGENTS.md you already import isn't loaded twice.
3. If your CLAUDE.md only says "read AGENTS.md" in words, replace that sentence with the @AGENTS.md import. Otherwise Claude sees the file only if it decides to open it.
4. If anyone on the team uses Windows, use the import rather than symlinking CLAUDE.md to AGENTS.md.
5. Start a new session, run /context, and confirm your instruction files show under Memory files.

#What is not confirmed

The 161-of-283 repo count is @torfinpd's own scan and hasn't been independently checked. Claude Code's docs say it doesn't read anything under .agents/, so Codex skills kept in .agents/skills need to be shared with Claude another way.