Hook Handler Has Type

Each hook handler object in .claude/settings.json MUST contain a "type" field set to "command", "http", "mcp_tool", "prompt", or "agent". Without a type field, Claude Code cannot dispatch the handler and the hook silently does nothing.

Antipatterns

• Missing type field. Defining a handler with only "command" or "prompt" but no "type" key. Claude Code cannot infer the handler type from its other fields.
• Invalid type value. Setting "type": "shell" or "type": "script" instead of the recognized values "command", "http", "mcp_tool", "prompt", or "agent".
• Type on the event, not the handler. Placing the "type" field at the event level ("PreToolUse": { "type": "command" }) instead of inside each handler object in the array.

Pass / Fail

Pass

{
  "hooks": {
    "PreToolUse": [
      { "type": "command", "command": "npm run lint" },
      { "type": "prompt", "prompt": "Check for security issues" }
    ]
  }
}

Fail

{
  "hooks": {
    "PreToolUse": [
      { "command": "npm run lint" }
    ]
  }
}

Limitations

Checks that at least one handler has a valid type field. Does not verify every handler individually when multiple handlers are defined for the same event.