# Get Custom Metadata Schema

Discover the custom metadata fields that have been used in events for a given use case. This is useful for building queries with `customMetadataFilters`.

```python
import roboflow

roboflow.login()

rf = roboflow.Roboflow()
ws = rf.workspace()

schema = ws.get_vision_event_metadata_schema("a1b3c8e1")

for field, info in schema["fields"].items():
    print(f"{field}: {info['types']}")
```

The response contains a `fields` dict mapping each discovered field name to its observed types (e.g., `["string"]`, `["number"]`). You can use this information to construct typed filters when [querying events](https://docs.roboflow.com/developer/python-sdk/vision-events/query-vision-events):

```python
page = ws.query_vision_events(
    "a1b3c8e1",
    customMetadataFilters=[
        {"field": "temperature", "operator": "gt", "value": 70, "type": "number"}
    ],
)
```

For more details, see the [REST API reference](https://docs.roboflow.com/developer/rest-api/vision-events/get-custom-metadata-schema).