# Metafield definition validation types

> The catalog of validation rule types a metafield definition can use.

A **Metafield definition validation type** is one kind of validation rule - `min_length`, `max_length`, `min_value`, `max_value`, `max_precision`, `json_schema`, and so on. This is a **read-only reference** resource: list the types to discover the valid values for a [validation](/api/product-management/metafield-definition-validations/)'s `name`.

Which types apply to a given definition depends on its data type - the authoritative per-type list is the `allowedValidations` field on [Metafield definition types](/api/product-management/metafield-definition-types/).

## The Metafield definition validation type object

## Conventions

All requests require an OAuth 2.0 bearer token and the organization scope header:

```
Authorization: Bearer <token>
X-Flowkiwi-Organization-Id: <organization-id>
```

This resource is read-only - it has no create, update or delete operations.