JSON → GraphQL SDL
GraphQL & API Architecture

JSON to GraphQL SDL Schema Generator (Types, Queries & Inputs)

Generate GraphQL schema definition language (SDL) object types, input types, and query schemas from JSON objects.

100% Client-Side Privacy
Zero Server Transmission
Presets:
GraphQL Schema Compiler Options & Scalar Mapping
Root: OrderCheckout•smart•
Input json label
"""
GraphQL Schema Definition Language (SDL)
Generated from JSON payload via ToolsAA Engine
Timestamp: 2026-10-16T17:04:31.669Z
"""

# Custom Scalar Directives
scalar DateTime

type Customer {
  id: Int!
  fullName: String!
  email: String!
  verified: Boolean!
  lastLoginEpoch: Int!
}

type Item {
  sku: String!
  quantity: Int!
  unitPrice: Float!
  discountCode: String!
}

type ShippingAddress {
  street: String!
  city: String!
  stateCode: String!
  postalCode: String!
  country: String!
}

type OrderCheckout {
  orderId: ID!
  uuid: ID!
  createdAt: DateTime!
  status: String!
  customer: Customer
  items: [Item!]!
  shippingAddress: ShippingAddress
  subtotal: Float!
  taxAmount: Float!
  total: Float!
  isGift: Boolean!
  trackingNumber: String
}

# Input Types for Mutations & Filters
input CustomerInput {
  id: Int
  fullName: String
  email: String
  verified: Boolean
  lastLoginEpoch: Int
}

input ItemInput {
  sku: String
  quantity: Int
  unitPrice: Float
  discountCode: String
}

input ShippingAddressInput {
  street: String
  city: String
  stateCode: String
  postalCode: String
  country: String
}

input OrderCheckoutInput {
  orderId: ID
  uuid: ID
  createdAt: DateTime
  status: String
  customer: CustomerInput
  items: [ItemInput!]!
  shippingAddress: ShippingAddressInput
  subtotal: Float
  taxAmount: Float
  total: Float
  isGift: Boolean
  trackingNumber: String
}

# Standard CRUD Query Operations
type Query {
  getCustomer(id: ID!): Customer
  listCustomers(limit: Int = 20, offset: Int = 0): [Customer!]!
}

# Standard CRUD Mutation Operations
type Mutation {
  createCustomer(input: CustomerInput!): Customer!
  updateCustomer(id: ID!, input: CustomerInput!): Customer!
  deleteCustomer(id: ID!): Boolean!
}

schema {
  query: Query
  mutation: Mutation
}
Stats types4
Stats inputs4
Stats fields26

Client-Side Processing

High-performance processing executed entirely in browser memory.

Zero Server Upload Privacy

All data payloads remain strictly local with zero external server communication.

Production Ready Export

Clean, optimized output formats ready for immediate deployment.

Technical Reference & Architecture Guide

JSON to GraphQL SDL Schema Generator (Types, Queries & Inputs) Developer Guide — Reference Guide

Generate GraphQL schema definition language (SDL) object types, input types, and query schemas from JSON objects.

Key Parameters & Controls

Root Type NameString

Specifies the identifier name assigned to the top-level GraphQL object type generated from the root JSON payload.

Default: Root
Generate Input TypesBoolean

Automatically produces corresponding GraphQL input definitions with the 'Input' suffix suitable for mutation variables.

Default: true
Nullability StrategyEnum (strict | loose | infer)

Determines whether fields append non-null exclamation marks (!). 'infer' marks fields non-null only when all sample instances contain values.

Default: infer
Query & Mutation BoilerplateBoolean

Generates root Query and Mutation type scaffolds with sample fetch, filter, and mutation signatures for rapid API prototyping.

Default: true

Pro Tips & Best Practices

Array Schema Normalization

When converting JSON arrays with heterogeneous objects, the generator aggregates keys across all items and marks inconsistent fields as nullable to avoid schema parsing errors.

Strict Input Type Separation

The GraphQL specification prohibits object types from being used as mutation arguments. Always enable 'Generate Input Types' to create valid, dedicated input schemas.

Int, Float, and ID Scalar Inference

Fields named 'id' or ending in '_id' with UUID or numeric formats are automatically assigned the GraphQL 'ID' scalar instead of generic 'String' or 'Float'.

Common Gotchas & Troubleshooting

Invalid GraphQL field identifiers with hyphens or spaces

GraphQL SDL field names must match /[_A-Za-z][_0-9A-Za-z]*/. The converter automatically transforms hyphenated keys (e.g., 'user-id') into camelCase ('userId').

Type name collisions in deeply nested anonymous objects

Nested objects sharing identical property names inherit parent context prefixes (e.g., 'AuthorAddress' vs 'CompanyAddress') to prevent duplicate type declarations.

Frequently Asked Questions

What is GraphQL SDL and where can I use the generated output?▼

GraphQL Schema Definition Language (SDL) is the official syntax for declaring GraphQL schemas. The output is 100% compliant with Apollo Server, GraphQL Yoga, NestJS, AWS AppSync, and GraphQL Code Generator.

How does the generator distinguish between Int and Float numbers?▼

Numbers without decimals falling within the 32-bit signed integer boundary are typed as GraphQL 'Int', whereas values containing fractions are typed as 'Float'.

How are nested JSON objects and arrays converted?▼

Nested objects are extracted into standalone GraphQL object types, and JSON arrays are converted into typed lists using the GraphQL syntax (e.g., '[Comment!]!').

Is my JSON payload transmitted to any external server?▼

No. All parsing, schema inference, and SDL code generation execute entirely client-side in your browser with zero network requests or data logging.

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