Codex — Rules
- File format
- Markdown
- Discovery path
-
AGENTS.md - Global install path
-
~/.codex - Syllago install method
- Symlink, Direct copy
- Symlink support
- Yes
Features
How each feature converts to syllago's canonical format. See format conversion for what these statuses mean.
Fields
Native frontmatter or config fields this provider exposes. The first column is the provider's own field name; the canonical key column links to syllago's cross-provider equivalent.
| Provider field | Conversion | Canonical key | Summary |
|---|---|---|---|
project_doc_fallback_filenames | Translated Conversion type: Translated Actively mapped to the target provider’s equivalent field during conversion. Learn more → | — | Native rules filename is AGENTS.md, with configurable fallback list via config.toml project_doc_fallback_filenames. |
project_doc_max_bytes | Dropped Conversion type: Dropped Can’t be meaningfully preserved. Removed from the output with a portability warning. Learn more → | — | Configurable byte cap on AGENTS.md reads via config.toml project_doc_max_bytes; prevents oversized rules files from blowing the context window. |
features.child_agents_md | Not portable Conversion type: Not portable Unique to this provider — can’t be carried across providers. Learn more → | — | When features.child_agents_md is enabled, Codex emits scope/precedence guidance and combines AGENTS.md files across a directory hierarchy. |
Other features
Behaviors, conventions, and capabilities that aren't tied to a single named field — things like path-based activation, discovery rules, and lifecycle behavior.
| Feature | Conversion | Summary |
|---|---|---|
cross_provider_recognition | Translated Conversion type: Translated Actively mapped to the target provider’s equivalent field during conversion. Learn more → | agents_md_filename: Codex reads AGENTS.md files using the standard filename used by multiple providers |
hierarchical_loading | Translated Conversion type: Translated Actively mapped to the target provider’s equivalent field during conversion. Learn more → | hierarchical_agents_md: Codex loads AGENTS.md from subdirectories with defined precedence (deeper overrides higher) |
Sources
| Source |
|---|
| https://raw.githubusercontent.com/openai/codex/main/docs/agents_md.md |
| https://raw.githubusercontent.com/openai/codex/main/AGENTS.md |