Claude/Code/Hook

• Hooks – Claude Code

  • Claude/Code's implementation of AI/Agent/Hook: commands the host runs at named lifecycle events, configured under the hooks key of a settings file — ~/.claude/settings.json, .claude/settings.json, .claude/settings.local.json, managed policy settings, a plugin's hooks/hooks.json, or skill and agent frontmatter.
  • Event names are PascalCase and the documented set runs past thirty, from SessionStart and UserPromptSubmit through PreToolUse, PostToolUse, SubagentStart, SubagentStop, PreCompact, and SessionEnd.
  • A PreToolUse hook can block the call it wraps, either by exiting with code 2 or by returning permissionDecision: "deny" with a reason.
  • Plugin hooks receive CLAUDE_PLUGIN_ROOT and CLAUDE_PLUGIN_DATA. Codex/Hook passes the same two variable names as a legacy alias, which is the narrow sense in which Codex is "Claude-compatible" on hooks.

  • Events with their own pages

    • Claude/Code/Hook/SessionStart
    • Claude/Code/Hook/PreCompact