#Codex Rules & Hooks

Rules and hooks give teams stronger control over what Codex may do and how workflows are checked.

#1. Rules

Rules are policy checks, often written with Starlark-style prefix rules, that allow, block, or require approval for command patterns.

#What They Solve

Rules help prevent destructive commands, unsafe network usage, credential exposure, or unreviewed production changes.

#Format: Starlark prefix_rule()

Rules usually match command prefixes and define what action should happen.

#Compound Commands

Be careful with compound commands. A safe prefix can become unsafe if chained with another shell command.

#Sources And Enterprise Enforcement

Rules may come from user config, project config, or managed enterprise policy. Managed rules should be treated as non-bypassable.

#2. Hooks

Hooks run scripts at lifecycle events.

#What They Solve

Hooks can enforce formatting, run checks, collect diagnostics, or integrate with internal systems.

#Lifecycle Events

Events may include pre-command, post-command, session start, or task completion depending on the surface and configuration.

#Configuration Format

Keep hook configuration explicit and version controlled when it affects team workflows.

#Script Input And Output

Hooks should receive structured input and return structured output when possible.

#Common Uses

• Block unsafe commands.
• Run linters before handoff.
• Attach audit metadata.
• Notify internal systems.

#Trust Model

Hooks execute code. Treat them as trusted project or organization infrastructure.

#Rules vs Hooks vs AGENTS.md

• Rules enforce command policy.
• Hooks run lifecycle automation.
• AGENTS.md communicates coding and workflow instructions.

#Next Steps

Continue with Computer Use.