Code & Schema Documentation

TypeScript Interface & Zod Schema Generation Guide

Step-by-step tutorial on converting raw JSON API responses into strongly-typed TypeScript declarations and runtime Zod validation schemas.

Type safety is critical for modern full-stack web applications. Converting raw JSON payloads into TypeScript interfaces eliminates runtime undefined errors.

1. Inferring Types from Dynamic Data

The generator inspects primitive values, nullability, nested dictionaries, and homogeneous arrays:

export interface UserProfile {
  id: string;
  name: string;
  email: string;
  age: number;
  tags: string[];
  settings: {
    theme: 'dark' | 'light';
    notifications: boolean;
  };
}

2. Synthesizing Runtime Zod Schemas

import { z } from 'zod';

export const UserProfileSchema = z.object({ id: z.string(), name: z.string(), email: z.string().email(), age: z.number().int().positive(), tags: z.array(z.string()), settings: z.object({ theme: z.enum(['dark', 'light']), notifications: z.boolean() }) });

export type UserProfile = z.infer<typeof UserProfileSchema>;

Put this into practice with the JSON to TypeScript

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