> For the complete documentation index, see [llms.txt](https://emotiv.gitbook.io/cortex-api/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://emotiv.gitbook.io/cortex-api/markers/marker-object.md).

# Marker object

A marker object includes these fields:

| Name          | Type                     | Description                                                                                                                                                                                                 |
| ------------- | ------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| uuid          | `string`                 | The id of the marker.                                                                                                                                                                                       |
| type          | `string`                 | Can be "interval" or "instance".                                                                                                                                                                            |
| value         | `string or number`       | The value you set in [injectMarker](/cortex-api/markers/injectmarker.md).                                                                                                                                   |
| label         | `string`                 | The label of the marker.                                                                                                                                                                                    |
| port          | `string`                 | <p>The port of the marker, ie where the marker comes from.<br>Examples: "Software", "Serial", etc...</p>                                                                                                    |
| startDatetime | `string (ISO date time)` | The timestamp you set in [injectMarker](/cortex-api/markers/injectmarker.md).                                                                                                                               |
| endDatetime   | `string (ISO date time)` | <p>The timestamp you set in <a href="/pages/-LfwRU1ckxkSAmoAOnNp">updateMarker</a>.</p><p>If you didn't call this method, then <strong>endDatetime</strong> is equal to <strong>startDatetime</strong>.</p> |
| extras        | `object`                 | Can be any extra information you want to associate with this marker.                                                                                                                                        |

## Examples

An instance marker:

```javascript
{
    "extras": {},
    "label": "test2",
    "port": "Cortex Example",
    "startDatetime": "2019-06-06T15:57:41.529661+07:00",
    "endDatetime":   "2019-06-06T15:57:41.529661+07:00",
    "type": "instance",
    "uuid": "26fccfd8-e487-4623-910a-1ba8591fcdcf",
    "value": 42
}
```

An interval marker:

```javascript
{
    "extras": {},
    "label": "test2",
    "port": "Cortex Example",
    "startDatetime": "2019-06-06T15:57:41.529661+07:00",
    "endDatetime":   "2019-06-06T15:57:49.530743+07:00",
    "type": "interval",
    "uuid": "26fccfd8-e487-4623-910a-1ba8591fcdcf",
    "value": 42
}
```