---
title: 'Level 21: Extend the Lightning CLI'
description: Extend the functionality of the Lightning CLI.
canonical: 'https://lightning.ai/docs/pytorch/stable/level-up/expert/expert_level_22'
---
# Level 21: Extend the Lightning CLI {#level-21-extend-the-lightning-cli}

Extend the functionality of the Lightning CLI.

- [Customize configs for complex projects](/docs/pytorch/2.6.6/reference/cli/lightning_cli_advanced_3.md) — Learn how to connect complex projects with each Registry.

- [Extend the Lightning CLI](/docs/pytorch/2.6.6/reference/cli/lightning_cli_expert.md) — Customize the Lightning CLI

---

**Navigation**

- Parent: [Expert skills](/docs/pytorch/2.6.6/level-up/expert.md)