Codex CLI AGENTS.md 32 KiB Default Cap and How to Raise It

Codex CLI stops loading AGENTS.md instructions once the combined size of the files it found reaches project_doc_max_bytes, which is 32 KiB (32,768 bytes) by default, per OpenAI's AGENTS.md guide. The guide documents no warning when the cap is reached. Keep AGENTS.md concise, split large files across nested directories, or raise the cap in ~/.codex/config.toml. The example below doubles it to 64 KiB (65,536 bytes) and adds fallback filenames, which Codex reads in a directory that has no AGENTS.md.

# ~/.codex/config.toml
project_doc_max_bytes = 65536
project_doc_fallback_filenames = [
  "TEAM_GUIDE.md",
  ".agents.md",
]

Keep these keys above any [table] header in the file, and restart Codex or run a new command so the change loads.

Source: OpenAI Codex docs, Custom instructions with AGENTS.md.