# Get Custom Metadata Schema

Retrieve the schema of custom metadata fields that have been used in events for a given use case. This is useful for discovering what metadata fields are available for filtering in [query requests](/developer/rest-api/vision-events/query-vision-events.md).

**Required scope:** `vision-events:read` or `device:read`

{% openapi src="/files/XCSsl1XUH9tiFJObaN6D" path="/vision-events/custom-metadata-schema/{useCaseId}" method="get" %}
[openapi.yaml](https://1284666567-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fe5GEiPeDoFksvZv1vH3A%2Fuploads%2Fgit-blob-d74beeed17fc5b3f8e39dcc93a9e9adaa7837101%2Fopenapi.yaml?alt=media)
{% endopenapi %}

### Path Parameters

* **`:useCaseId`** (string, required): The use case ID.

### Example Request

```bash
curl "https://api.roboflow.com/vision-events/custom-metadata-schema/a1b3c8e1" \
  -H "Authorization: Bearer YOUR_API_KEY"
```

### Example Response

{% tabs %}
{% tab title="200" %}

```json
{
  "fields": {
    "production_line": {
      "types": ["string"]
    },
    "temperature": {
      "types": ["number"]
    },
    "is_overtime": {
      "types": ["boolean"]
    }
  }
}
```

Each field in the `fields` object includes:

* **`types`** (array of strings): The data types observed for this field, each one of `string`, `number`, or `boolean`. A field may have multiple types if different events used different types for the same key.
  {% endtab %}

{% tab title="403" %}

```json
{
  "error": "Insufficient permissions for this resource."
}
```

{% endtab %}
{% endtabs %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.roboflow.com/developer/rest-api/vision-events/get-custom-metadata-schema.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.