Infer TypeScript interfaces or aliases from a JSON sample, merging object arrays and exposing optional, readonly, precision, and runtime limits.
Choose your path
Generate a readable TypeScript sample shape from one JSON text by merging observed object-array variants while keeping compile-time declarations separate from runtime validation and compatibility proof.
Create stable, readable declarations from a versioned example.
Choose root/options, inspect nested PascalCase names, merged arrays and warnings, then save the exact sample/type record.
Starts implementation without treating sample inference as the authoritative schema.
Inspect top-level arrays/primitives, missing fields, nulls, unions, quoted keys and type/interface syntax.
Exercise boundary samples, compile separately and reconcile against the consumer/schema version.
Rejects malformed or overconfident declarations before merge.
Keep runtime parsing, negative tests and accessible operation visible.
Use named options/editors/copy/save on desktop/mobile and follow the runtime warning path.
Pairs the output with runtime validation and can operate it without clipped code or unnamed controls.
Outputs and checklists are planning aids. Review the linked current authorities and the records, terms, instructions, and requirements that apply to your exact situation before a consequential decision.
This tool is part of these guided projects. Each project provides step-by-step instructions with checklists and all the tools you need in one place.
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One JSON text is parsed with explicit duplicate-member and precision warnings. Objects, arrays, primitives and null are valid top-level samples.
Every observed object-array item contributes fields and unions; properties absent from some items become optional. Empty arrays remain unknown by design.
Generated declarations describe only the sample. They do not validate network data, prove schema compatibility, authorize fields, or replace compilation and negative tests.
Updated: July 2026
An implementer generates readable declarations from a versioned example, then reconciles them with the actual schema and consumer policy.
A reviewer checks merged array variants, automatically optional properties, null unions, quoted keys, and warning text before acceptance.
A runtime owner links the generated sample type to schema validation, negative tests, authorization, change policy, and release evidence.
Generate a readable TypeScript starting point from one sample, merge observed object-array fields, and keep runtime validation and compatibility evidence separate.