Validation

In order to prevent errors happening during request processing or sending invalid queries to the upstream Tyk supports the validation of GraphQL queries and schemas.

Query Validation

Tyk’s native GraphQL engine supports validating GraphQL queries based on the GraphQL Specification.

Both the GraphQL engine in front of your existing GraphQL API as well as any Universal Data Graph you build gets protected with a validation middleware.

This means, no invalid request will be forwarded to your upstream. The Gateway will catch the error and return it to the client.

Schema Validation

A broken schema can lead to undesired behaviors of the API including queries not being processed by the GraphQL middleware. As the search for the root cause for such a malfunction can be tedious, Tyk provides schema validation.

The schema validation will prevent you from saving or updating an API with a broken schema. This includes schemas breaking the following rules:

• No duplicated operation types (Query, Mutation, Subscription)
• No duplicated type names
• No duplicated field names
• No duplicated enum values
• No usage of unknown types

When using the Dashboard API the response for a broken schema will be a 400 Bad Request with a body containing the validation errors. For example:

{
  "Status": "Error",
  "Message": "Invalid GraphQL schema",
  "Meta":null,
  "Errors": [
    "field 'Query.foo' can only be defined once"
  ]
}