# Custom Validators

Extend the built-in [validate()](../reference/validate.md#gdtest_sec_index_hero.validate) with custom rules.

``` python
from gdtest_sec_index_hero import validate

def validate_positive(record):
    base_ok = validate({'value': int}, record)
    return base_ok and record['value'] > 0

assert validate_positive({'value': 42})
assert not validate_positive({'value': -1})
```