> ## Documentation Index
> Fetch the complete documentation index at: https://elementary-ele-2784-fix-alerts-configuration-links-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# JSON schema

`elementary.json_schema`

Allows validating that a string column matches a given JSON schema. The test expects a JSON schema as input,
defined according to the [JSON schema standard](https://json-schema.org/), defined in YAML format (see an example below).

This test along with the relevant JSON schema can be auto-generated (see details below).

<Info>
  This test relies on our [Python tests capability](/data-tests/python-tests), and is currently only supported for
  Snowflake and BigQuery data warehouses.
</Info>

### Auto-generate JSON schema tests

Elementary provides the `generate_json_schema_test` macro in order to auto-generate the JSON schema for a given
column using existing data.

Example usage:

```shell
dbt run-operation elementary.generate_json_schema_test --args '{"node_name": "login_events", "column_name": "raw_event_data"}'
```

Will print:

```shell
Please add the following test to your model configuration:
----------------------------------------------------------

columns:
  - name: raw_event_data
    tests:
      - elementary.json_schema:
          type: object
          properties:
            event_id:
              type: integer
            event_name:
              type: string
            event_args:
              type: array
              items:
                type: string
          required:
            - event_id
            - event_name
```

*Note: The `generate_json_schema_test` macro relies on a 3rd-party python library called `genson`. If you are using
BigQuery, you will need to pre-install this library in your Dataproc cluster (See [dbt's documentation on Python models](https://docs.getdbt.com/docs/building-a-dbt-project/building-models/python-models#specific-data-platforms)
for more details)*

<RequestExample>
  ```yml Models
  version: 2

  models:
    - name: < model name >
      columns:
        - name: < column name >
          tests:
            - elementary.json_schema: <json schema parameters>
  ```

  ```yml Models example
  version: 2

  models:
    - name: login_events
      columns:
        - name: raw_event_data
          tests:
            - elementary.json_schema:
                type: object
                properties:
                  event_id:
                    type: integer
                  event_name:
                    type: string
                  event_args:
                    type: array
                    items:
                      type: string
                required:
                  - event_id
                  - event_name
  ```
</RequestExample>