> For the complete documentation index, see [llms.txt](https://docs.sparkframework.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sparkframework.dev/documentation/developer-guide/plugins/spellbooks/extensions.md).

# Extensions

Extension data types provided by the Spellbooks plugin that add fields to other plugins' entries.

| Extension               | Extends      | Description                  |
| ----------------------- | ------------ | ---------------------------- |
| Classes Extension       | `ClassEntry` | Spellbooks granted per class |
| Quest Rewards Extension | `QuestEntry` | Spellbook as quest reward    |

See [Extensions](/documentation/developer-guide/core-systems/extensions.md) for how to create custom extensions.


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