How do I generate TypeScript types from OpenAPI?

Paste your OpenAPI 2.x or 3.x spec. Specway walks every entry under components.schemas (or definitions for Swagger 2.0) and emits an `interface` or `type` for each, with proper nesting, $ref support, enums, oneOf/anyOf/allOf, and array/object types. Copy the generated code straight into your project.

How is this different from openapi-typescript?

openapi-typescript (the npm package) is the gold-standard CLI tool — it generates a single types file plus operations interfaces, includes path/method maps, and integrates with openapi-fetch for end-to-end type safety. This widget is a quick one-off — paste, copy, done. For production, use openapi-typescript in your build.

Does it generate types for operations, not just schemas?

Just schemas at the moment — the components.schemas / definitions section. For full operation types (request params, response bodies typed by status code), use openapi-typescript's path-based output. Most use cases for a quick paste-and-go tool only need the schema types, which is what this generates.

How does it handle $ref?

Internal references (#/components/schemas/X) become a TypeScript reference to that interface. External refs (other files, URLs) are not resolved in the browser — paste the merged single-file spec, or use the openapi-typescript CLI which resolves them properly.

What about oneOf, anyOf, allOf?

oneOf and anyOf become union types (A | B | C). allOf becomes intersection (A & B & C). For tagged unions (discriminator), the widget emits the union but doesn't generate the discriminator narrowing — for that, use openapi-typescript with `--enable-discriminator`.

Why are some properties marked optional when they're required in the API?

TypeScript optionality reflects the OpenAPI `required` array. If a property isn't in `required`, it's `?:`. If your API actually requires fields the spec doesn't list, the spec is wrong — fix it. Generated types are downstream of the spec; they can't be more accurate than the source.

Can I auto-regenerate on spec changes?

In CI: run `openapi-typescript spec.yaml --output types.ts` on every push. Specway has it built-in — types are auto-generated on every spec import and exposed as a downloadable file alongside the docs.

How do I generate TypeScript types from OpenAPI?

Paste your OpenAPI 2.x or 3.x spec. Specway walks every entry under components.schemas (or definitions for Swagger 2.0) and emits an `interface` or `type` for each, with proper nesting, $ref support, enums, oneOf/anyOf/allOf, and array/object types. Copy the generated code straight into your project.

How is this different from openapi-typescript?

openapi-typescript (the npm package) is the gold-standard CLI tool — it generates a single types file plus operations interfaces, includes path/method maps, and integrates with openapi-fetch for end-to-end type safety. This widget is a quick one-off — paste, copy, done. For production, use openapi-typescript in your build.

Does it generate types for operations, not just schemas?

Just schemas at the moment — the components.schemas / definitions section. For full operation types (request params, response bodies typed by status code), use openapi-typescript's path-based output. Most use cases for a quick paste-and-go tool only need the schema types, which is what this generates.

How does it handle $ref?

Internal references (#/components/schemas/X) become a TypeScript reference to that interface. External refs (other files, URLs) are not resolved in the browser — paste the merged single-file spec, or use the openapi-typescript CLI which resolves them properly.

What about oneOf, anyOf, allOf?

oneOf and anyOf become union types (A | B | C). allOf becomes intersection (A & B & C). For tagged unions (discriminator), the widget emits the union but doesn't generate the discriminator narrowing — for that, use openapi-typescript with `--enable-discriminator`.

Why are some properties marked optional when they're required in the API?

TypeScript optionality reflects the OpenAPI `required` array. If a property isn't in `required`, it's `?:`. If your API actually requires fields the spec doesn't list, the spec is wrong — fix it. Generated types are downstream of the spec; they can't be more accurate than the source.

Can I auto-regenerate on spec changes?

In CI: run `openapi-typescript spec.yaml --output types.ts` on every push. Specway has it built-in — types are auto-generated on every spec import and exposed as a downloadable file alongside the docs.

Free Tool

OpenAPI → TypeScript (2026)

Generate TypeScript interfaces and types from your OpenAPI / Swagger components.schemas. Handles enums, $refs, oneOf/anyOf/allOf, nullable, and arrays. Copy the result straight into your project.

OpenAPI / Swagger spec

/**
 * Generated by Specway — https://specway.com/tools/openapi-to-typescript
 * Edit your OpenAPI spec, not this file.
 */

export interface User {
  id: number;
  email: string;
  name?: string;
  role?: "admin" | "member" | "guest";
  tags?: string[];
  team?: Team;
}

export interface Team {
  id: string;
  name: string;
  memberCount?: number;
}

What gets generated

One interface per object schema in components.schemas (or definitions for Swagger 2.0).
type aliases for enums and primitive schemas.
Optional fields (?:) for anything not in required.
Union types for oneOf and anyOf; intersection types for allOf.
$ref references resolve to the named interface.
nullable: true appends | null.

When to use this vs openapi-typescript

This widget is for the one-off: someone sent you a spec in Slack, you need types in your editor right now. Paste, copy, done.

For production: openapi-typescript

For ongoing projects, install openapi-typescript as a dev dep:

npm i -D openapi-typescript
npx openapi-typescript spec.yaml -o src/api.d.ts

Pair with openapi-fetch for fully-typed request/response handling. Or use Specway — auto- generated types are part of every docs publish.

Ship API docs that stay this clean

Specway turns your OpenAPI spec into a branded developer portal — auto-synced, searchable, with built-in playground and code samples in every language. Free tier available.

Related tools

OpenAPI Validator

Validate the spec before generating types.

OpenAPI Viewer

Browse the operations the types will cover.

JSON Schema Validator

Validate runtime data against a schema.

OpenAPI → Postman

Generate a Postman collection from the same spec.

Frequently asked questions

/** * Generated by Specway — https://specway.com/tools/openapi-to-typescript * Edit your OpenAPI spec, not this file. */ export interface User { id: number; email: string; name?: string; role?: "admin" | "member" | "guest"; tags?: string[]; team?: Team; } export interface Team { id: string; name: string; memberCount?: number; }

What gets generated

One interface per object schema in components.schemas (or definitions for Swagger 2.0).
type aliases for enums and primitive schemas.
Optional fields (?:) for anything not in required.
Union types for oneOf and anyOf; intersection types for allOf.
$ref references resolve to the named interface.
nullable: true appends | null.

Frequently asked questions

What gets generated

One interface per object schema in components.schemas (or definitions for Swagger 2.0).
type aliases for enums and primitive schemas.
Optional fields (?:) for anything not in required.
Union types for oneOf and anyOf; intersection types for allOf.
$ref references resolve to the named interface.
nullable: true appends | null.

Frequently asked questions

What gets generated

One interface per object schema in components.schemas (or definitions for Swagger 2.0).
type aliases for enums and primitive schemas.
Optional fields (?:) for anything not in required.
Union types for oneOf and anyOf; intersection types for allOf.
$ref references resolve to the named interface.
nullable: true appends | null.

Frequently asked questions