GraphQL

One major difference between GraphQL and REST APIs is how they handle errors. In a REST API, different HTTP status codes indicate the outcome of a request. For example, a 200 status code means the request was successful, while a 400 status code means there was a client error.

In contrast, GraphQL always returns a 200 status code, even if there are errors in the response body. The GraphQL spec suggests that servers respond with a structured errors field. This makes errors machine-readable but drops the semantic meaning of HTTP status codes. Everyone knows what a 404 status code means but a GraphQL server will instead return a 200 with application-specific errors in the errors field in the response. This means that to effectively debug GraphQL, you typically have to comb through every single request to identify errors.

That's why we've built special error handling support for GraphQL.

We added extra logic to the dev tools section to mark GraphQL requests as errors even if they return an HTTP 200 code, if they have an errors object inside the response body.

Here's a Jam of Jam, the GraphQL requests are red for "error" even though they return 200.