// Use when the user asks about Codex Rules behavior, injected project rules, supported rule file locations, matching, or environment configuration.
| name | rules |
| description | Use when the user asks about Codex Rules behavior, injected project rules, supported rule file locations, matching, or environment configuration. |
Codex Rules is automatic once the plugin is enabled. It injects:
SessionStart and UserPromptSubmitapply_patch by defaultDynamic PostToolUse output is injected as additional context and is deduplicated per plugin data session. Codex Rules does not rewrite tool output.
Supported project sources:
AGENTS.mdCLAUDE.mdCONTEXT.md.sisyphus/rules/**/*.md.claude/rules/**/*.md.cursor/rules/**/*.md.github/instructions/**/*.md.github/copilot-instructions.mdSupported environment knobs:
CODEX_RULES_DISABLED=1CODEX_RULES_MODE=both|static|dynamic|offCODEX_RULES_MAX_RULE_CHARS=<number>CODEX_RULES_MAX_RESULT_CHARS=<number>CODEX_RULES_ENABLED_SOURCES=AGENTS.md,.sisyphus/rulesThe legacy PI_RULES_* variables are accepted as fallbacks for users migrating from pi-rules.