Are nullable fields marked with ! in GraphQL?

Fields always present in the sample are marked non-null (!); fields sometimes absent are nullable.

How are JSON arrays mapped in GraphQL types?

Arrays become GraphQL list types (e.g., [String]) with nullability based on observed data.

A basic Query type with a single field returning the root type is optionally generated as a starter schema.

Yes. The SDL output can be passed directly to the typeDefs option in Apollo Server.

Paste JSON and get a GraphQL type definition with fields and scalar types inferred.

JSON Input

Code Output

Paste JSON and get a GraphQL type definition with fields and scalar types inferred.

Last updated: 2026-06-09 · Reviewed by Nham Vu