📐GraphQL SDL to TypeScript Converter Documentation & Guide
Web & Developer
Convert GraphQL Schema Definition Language (SDL) types, inputs, interfaces, and enums into strongly-typed TypeScript interfaces. Supports custom scalars, field nullability handling, and union string literal enums.
📋How to Convert GraphQL SDL to TypeScript
- 1. Paste GraphQL SDL: Enter your type, input, interface, and enum definitions into the schema textarea or click a preset.
- 2. Configure TypeScript Options: Select interface vs type constructs, union vs enum output, and configure nullable field conventions.
- 3. Generate & Copy Types: Click Generate TypeScript to inspect formatted TypeScript definitions ready for your frontend or backend.
⚙️GraphQL Schema Typings & Type-Safe Client Contracts
GraphQL schemas provide strict type definitions on the server, but frontend clients require corresponding TypeScript interfaces to prevent runtime errors.
• Nullability Mapping (!): Accurately translates non-null fields (
String!) to required types and nullable fields to T | null or optional properties (?).• Scalar Translation: Automatically maps standard GraphQL primitives (ID, String, Int, Float, Boolean) and custom scalars (DateTime, JSON) to TypeScript equivalents.
• Enum Optimization: Supports modern TypeScript string literal unions (
'A' | 'B') to avoid numeric enum runtime overhead.• Nested List Resolution: Correctly maps list dimensions, handling combinations like
[String!]!, [String]!, and [String].Compatible with Apollo Client, Urql, Relay, GraphQL Code Generator, and backend GraphQL servers (Yoga, Apollo Server, Mercurius).
💡Practical Use Cases
- Full-Stack Type Safety: Synchronize server schema contracts with React, Vue, or Angular client-side query hooks.
- Mock Data Fixtures: Quickly draft type-safe mock objects matching GraphQL query schemas for unit tests.
- API Contract Documentation: Share clear TypeScript interfaces with API consumers without requiring specialized GraphQL tooling.
100% Client-Side Privacy Guarantee:Schema parsing and TypeScript type generation run entirely locally in your browser memory. Zero schemas or API definitions are ever shared externally.
