OpenAI Codex · tool · fg-0496

Codex drops later AGENTS.md instructions once project guidance passes 32 KiB

Rules from the AGENTS.md closest to the working directory are missing

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

project_doc_max_bytes, 32 KiB by default, caps how much project guidance Codex reads, and Codex stops adding files once the combined size reaches it. Files nearer the working directory come last in the chain, so they are the ones cut.

Fix

Raise project_doc_max_bytes in config.toml, or trim the root file and move detail into nested files.

Apply

# ~/.codex/config.toml
project_doc_max_bytes = 65536

Affects: Codex CLI, IDE extension, and ChatGPT desktop app, as of 2026-10

Sources

Have your agent know this before it fails

claude mcp add --transport http footgun https://getfootgun.com/api/mcp