> ## Documentation Index
> Fetch the complete documentation index at: https://developers.notion.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Place custom blocks with markdown

> Place an instance of an existing custom block definition on a Notion page.

<Warning>
  Custom blocks are in private alpha:

  * Do not discuss publicly or share with anyone outside your workspace.
  * Access must be enabled per workspace. Installing the SDK does not grant access.
  * These APIs may experience breaking changes without notice.
</Warning>

## Place a custom block

Use a self-closing tag on its own line to place a custom block. Replace the example UUID with a definition ID for a custom block deployed to your workspace.

```markdown theme={null}
Text before the custom block.

<custom-block definition-id="11111111-1111-4111-8111-111111111111" />

Text after the custom block.
```