> ## 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.

# Comment attachment

> The Comment Attachment object represents [files](/reference/file-object) that have been attached to a [Comment](/reference/comment-object).

<Note>
  Comments can currently support up to 3 attachments.
</Note>

## Request format (input)

### Object properties

After following the [Working with files and media](/guides/data-apis/working-with-files-and-media) guide, provide an array of objects under the `attachments` parameter in the [Create comment](/reference/create-a-comment) API, each containing the following properties:

| Parameter | Type | Description | Example value |
| :- | :- | :- | :- |
| `file_upload_id` | `string` (UUID) | ID of a [File Upload](/reference/file-upload) with a status of `"uploaded"` | `"2e2cdb8b-9897-4a6c-a935-82922b1cfb87"` |
| `type` | `string` (optional) | Possible type values are:`"file_upload"` | `"file_upload"` |

Example Create Comment request:

<CodeGroup>
  ```json API request theme={null}
  {
    "parent": {
      "page_id": "d0a1ffaf-a4d8-4acf-a1ed-abae6e110418"
    },
    "rich_text": [
      {
        "text": {"content": "Thanks for the helpful page!"}
      },
    ],
    "attachments": {
      "file_upload_id": "2e2cdb8b-9897-4a6c-a935-82922b1cfb87"
    }
  }
  ```
</CodeGroup>

In the Notion app, when viewing a comment uploaded using the API, the user experience is automatically customized based on the detected category of the file upload. For example, uploading a `.png` file displays your attachment as an inline image instead of a regular file download block.

## Response format (output)

### Object properties

The response of Comment APIs like [Create comment](/reference/create-a-comment) contains `attachments` with the following fields:

| Field | Type | Description | Example value |
| :- | :- | :- | :- |
| `category` | `string` (enum) | The category of this attachment. Possible type values are: `"audio"`, `"image"`, `"pdf"`, `"productivity"`, and `"video"` | `"audio"` |
| `file` | `object` | A [file object](/reference/file-object#notion-hosted-files-type-file) containing type-specific configuration. | `{"url": "<https://s3.us-west-2.amazonaws.com/...">, "expiry_time": "2025-06-10T21:26:03.070Z"}` |

Example attachment object in Create Comment response:

<CodeGroup>
  ```json Comment Attachment Response theme={null}
  {
    "category": "video",
    "file": {
      "url": "https://s3.us-west-2.amazonaws.com/...",
      "expiry_time": "2025-06-10T21:26:03.070Z"
    }
  }
  ```
</CodeGroup>

The `file.url` is a temporary download link generated at the time of retrieving a comment. See the guide on [Retrieving existing files](/guides/data-apis/retrieving-files) to learn more about accessing the files you upload.

## Attachments that are still uploading

When someone attaches a file to a comment in the Notion app, Notion saves the comment before the file finishes uploading. Until the upload finishes, the file isn't listed in `attachments`, and the comment's `has_pending_attachments` field is `true`.

When the upload finishes, Notion sends a `comment.updated` [webhook event](/reference/webhooks-events-delivery) for the comment. Retrieve the comment again to get the file. If the upload fails, the file is removed from the comment, and Notion sends `comment.updated`, or `comment.deleted` if the comment has no text.

Comments created with the API aren't affected, because the [Create comment](/reference/create-a-comment) API only accepts files that have finished uploading.