What this does

Infers GraphQL schema definition language (SDL) types from a JSON sample. Nested objects become separate type declarations named after their field (a field calledorders holding objects produces type Order), and arrays become lists.

Example

Input

{
  "id": 42,
  "name": "Ada",
  "verified": true,
  "tags": [
    "admin",
    "dev"
  ],
  "orders": [
    {
      "sku": "A1",
      "qty": 2
    },
    {
      "sku": "B2",
      "qty": 1,
      "note": "gift"
    }
  ]
}

Output with default options

type Root {
  id: ID!
  name: String!
  verified: Boolean!
  tags: [String!]!
  orders: [Order!]!
}

type Order {
  sku: String!
  qty: Int!
  note: String
}

Inference rules

Scalars: strings are String, booleans Boolean. Numbers are Int only if every value is an integer within GraphQL's 32-bit range; otherwise Float.
ID: fields named id holding strings or integers become ID (switch off if you do not want that).
Nullability: a field present in every object and never null gets !. When an array holds several objects, a key missing from any of them, or null in any of them, stays nullable. Turn the option off to leave everything nullable.
Lists: elements of all arrays at the same position are merged, so [Order!]! reflects the union of the objects.
Unknowns: null-only values, empty arrays, empty objects, and mixed-type values use a custom scalar JSON, which the tool declares and flags for you.
Keys that are not valid GraphQL names are renamed with underscores and listed in a note. The root must be an object or an array of objects.

Things to know

The output only contains type definitions, not Query or Mutation roots, since those depend on how you expose the data. Inference is only as good as the sample, so paste several records for realistic nullability.

Privacy

The conversion runs in your browser. The JSON is never uploaded.

JSON to GraphQL Types Converter