> For the complete documentation index, see [llms.txt](https://docs.datasaur.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.datasaur.ai/advanced/extensions/metadata.md).

# Metadata

The **Metadata** extension allows you to view metadata attached to cells or lines in a project. Metadata can be embedded in input formats that support `metadata`, such as [JSON Advanced](/compatibility-and-updates/supported-formats.md#json_advanced), [Datasaur Schema](/compatibility-and-updates/supported-formats.md#datasaur-schema-format), or by using the [Import File Transformer](/workspace-management/file-transformer/import-transformer.md).

Metadata is supported in:

* **Span labeling projects**: Metadata is attached per line.

  <figure><img src="/files/3cW5vuaj9MqZLeOH77LD" alt=""><figcaption></figcaption></figure>
* **Row labeling projects**: Metadata is attached per cell.

  <figure><img src="/files/0edqlYQtqV8IKrOqxEQl" alt=""><figcaption></figcaption></figure>

## Structure

The structure for <mark style="color:red;">`CellMetadata`</mark> is defined as follows:

<pre class="language-json"><code class="lang-json">CellMetadata {
<strong>    key: string;
</strong>    value: string;
    type?: string;
    pinned?: boolean;
    config?: {
        backgroundColor: string;
        color: string;
        borderColor: string;
    }
}
</code></pre>

**Metadata object structure**:

* **key**: Identifier for the metadata item, represented as a string. Example: `"author"` .
* **value**: Content or data of the metadata item, represented as a string. Example: `"John Doe"` .
* **type** (optional): [MIME type](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types) used to display the metadata.
  * **Default**: `text/plain`
  * **Supported types**:
    * `text/plain`**:** Displays metadata as plain text.
    * `text/html`: Displays metadata as HTML content.
    * `image/*`**:** Displays metadata as an image. Supported image formats depend on [browser support](https://en.wikipedia.org/wiki/Comparison_of_browser_engines_\(graphics_support\)).
    * `audio/*`**:** Displays metadata as an audio player. Supported audio formats depend on [browser support](https://en.wikipedia.org/wiki/HTML5_audio#Supported_audio_coding_formats).
* **pinned** (optional): If `true`, the metadata appears at the top of the cell. Otherwise, it is available in the Metadata extension panel.
* **config** (optional): Customizes the appearance of `text/plain` metadata. All color fields support standard HTML color names and color codes.
  * **color:** Determines the text color of the metadata.
  * **backgroundColor:** Determines the background color of the metadata.
  * **borderColor:** Determines the border color of the metadata.

## Sample files

Below are sample files for span labeling and row labeling projects that include metadata.

{% file src="/files/JCAwZPTSMLA8a1dqXBmZ" %}

{% file src="/files/Bs72ZclTPFs3wngJ6uo0" %}