Hook Development for Codex Plugins

Overview

Hooks are event-driven automation scripts that execute in response to Codex events. Use hooks to validate operations, enforce policies, add context, and integrate external tools into workflows.

Key capabilities:

• Validate tool calls before execution (PreToolUse)
• React to tool results (PostToolUse)
• Enforce completion standards (Stop, SubagentStop)
• Load project context (SessionStart)
• Automate workflows across the development lifecycle

Hook Types

Prompt-Based Hooks (Recommended)

Use LLM-driven decision making for context-aware validation: