Error handling with dynamic clients

System-level errors

If the service returns a system-level error (which means the response body doesn't contain a valid GraphQL response document), the client invocation will (instead of returning a io.smallrye.graphql.client.Response) throw a io.smallrye.graphql.client.InvalidResponseException whose message contains information about the received status code, status message, and body contents.

Application-level errors

If the service returns one or more application-level errors (which means that there is valid GraphQL response in the body that has a non-empty errors entry), the client invocation will return a io.smallrye.graphql.client.Response as normal, and that object will contain information about the errors. Errors are represented as io.smallrye.graphql.client.GraphQLError objects and can be inspected after retrieving a list of all errors using response.getErrors().

[NOTE] An error response is considered application-level regardless of the HTTP status code as long as it contains a valid GraphQL response. We define a GraphQL response as a well-formed JSON document that contains at least one of errors, data and extensions entries, and no other entries beyond that.

It is also possible to convert a response's errors into a io.smallrye.graphql.client.GraphQLClientException by calling throwExceptionIfErrors() - the response has to be cast to ResponseImpl for this as of now. This method will, if there are any errors in the response, convert the errors into a GraphQLClientException and throw it.

If you need to access the HTTP response code and message pertaining to a response that contained application-level errors, refer to Accessing HTTP headers and response codes.