About JSON Schema → TypeScript

Convert a JSON Schema draft-07 document into TypeScript types. Part of the DevTools Surf developer suite. Browse more tools in the Converters collection.

Use Cases

• Import types from a documented OpenAPI/JSON Schema spec
• Generate strict types from a shared schema file
• Keep frontend and backend types in sync from a single source
• Generate client types automatically in a build pipeline

Tips

• Supports draft-07 'type', 'properties', 'required', 'enum', and nested object schemas
• String enums become union types of string literals
• Use the title field to control the generated interface name

Fun Facts

• JSON Schema draft-2020-12 is the current version but draft-07 is still the most widely deployed across tooling.
• JSON Schema was originally proposed in 2007 by Kris Zyp at Dojo Foundation and took 13 years to reach a stable specification.
• OpenAPI 3.1 (2021) was the first version to achieve full JSON Schema compatibility — previous versions used a restricted subset that caused constant developer frustration.

FAQ

Which JSON Schema draft?

Draft-07 is fully supported (the most common). Draft 2019-09 and 2020-12 features (unevaluatedProperties, dynamic refs) have partial support.

What about $ref resolution?

Local $refs are resolved (#/definitions/Foo). External $refs (http://example.com/schema.json) aren't fetched — inline them before conversion.

Does it generate runtime validators?

No — types only. For runtime validation pair with Ajv (which uses the same JSON Schema directly) or use the json-to-zod tool for a validator + types in one.

What about unions with oneOf/anyOf?

oneOf → TypeScript union. anyOf → intersection when possible, union otherwise. discriminator keys produce type guards for clean narrowing.