Use --init-only to Run Setup Hooks Without Starting a Session

The --init-only flag runs your initialization hooks and then exits immediately, without starting an interactive session or processing any prompt. This is useful for CI pipelines and setup scripts where you need Claude's hooks to prepare the environment but do not need a conversation.

claude --init-only

If you have SessionStart hooks configured in your settings, they will fire as normal. For example, you might have a hook that loads environment variables, validates tool versions, or syncs configuration:

{
  "hooks": {
    "SessionStart": [
      {
        "hooks": [
          {
            "type": "command",
            "command": ".claude/hooks/setup-env.sh"
          }
        ]
      }
    ]
  }
}

Running claude --init-only triggers that hook, runs the script, and exits with the appropriate status code. This lets you reuse your Claude Code hook infrastructure for general setup tasks.

There is also --init (without the -only suffix), which runs initialization hooks and then starts interactive mode. Use --init when you want to ensure hooks run before a normal session. Use --init-only when you only need the hooks.

# Run hooks then start interactive mode
claude --init

# Run hooks then exit
claude --init-only

Reuse your Claude Code hooks as a lightweight task runner, no session required.

via Claude Code CLI Reference