JSON to GraphQL Schema Generator

Currently the tool generates data type definitions only (e.g., type User { ... }). You need to manually add Query and Mutation types that reference the generated types. For example: type Query { user(id: ID!): User, users: [User!]! }. This is intentional because query and mutation design depends on your API requirements.

Fields named "id" or ending with "Id" or "_id" (e.g., userId, product_id) are mapped to the GraphQL ID scalar type. All other string fields use String. You can manually change any field's type in the generated SDL if the auto-detection doesn't match your needs.

By default, all fields are generated as non-nullable (e.g., name: String). JSON null values are mapped to String type. In GraphQL, you make fields nullable by removing the ! suffix (our output doesn't add !, so fields are nullable by default in GraphQL semantics). Add ! to fields that should be non-nullable.

Nested JSON objects are extracted into separate GraphQL type definitions. For example, {"user": {"address": {"city": "NYC"}}} generates type Address { city: String } and type User { address: Address }, maintaining clean type separation.

Yes. The generated SDL works with any GraphQL server implementation — Apollo Server, GraphQL Yoga, Mercurius, Express GraphQL, or any library that accepts GraphQL SDL strings. Just import the generated types into your schema definition.

The generator uses standard GraphQL scalars (String, Int, Float, Boolean, ID). Date strings remain as String type and nested objects become separate types. For custom scalars like DateTime or JSON, manually replace the generated types after generation.

GraphQL lists require a single element type. The first array element's type is used. For polymorphic arrays, consider using a GraphQL union type (union Result = User | Product) which you would define manually after generation.