# operation-known-types

Source: https://apigenie.pl/docs/linter/graphql/rules/operation-known-types

This rule checks that the types of variables and the type conditions of fragments are types of the schema.

## Rule Details

Unknown types are rejected by the server.

## Configuration

This rule has no options.

```yaml
version: "1.0"
commands:
  lint:
    graphql:
      rules:
        operation-known-types: warning
```

The rule can be disabled for a node and everything nested in it with an `# apigenie-lint-disable operation-known-types` comment on the node, or for a whole file with the comment at the top of the file, separated from the first definition by a blank line. It applies to operations and fragments.

## Examples

**Good**.

```graphql
query Users($kind: Kind) { users(kind: $kind) { id } }
```

**Bad**. The linter reports `Unknown type "UserKind".`.

```graphql
query Users($kind: UserKind) { users(kind: $kind) { id } }
```

## Compatibility

The rule checks operations against the schema files named by the `schema` property of the configuration, or against the type system of their own document. It reports nothing without a schema.