What OpenAPI versions does this support?

The converter works with OpenAPI 2.0 (Swagger) and OpenAPI 3.x schema definitions. Paste the components/schemas or definitions section from your spec.

OpenAPI to TypeScript Converter

Q: How are required vs optional fields handled?

Fields listed in the 'required' array are generated without '?'. Fields not in 'required' get the '?' optional modifier in the TypeScript interface.

Convert OpenAPI and Swagger schemas to TypeScript interfaces and types with AI — free, no login required.

Stop writing TypeScript interfaces by hand from your API spec. Paste your OpenAPI or Swagger schema definitions and get fully-typed TypeScript interfaces instantly — with correct optional fields, type mappings, and JSDoc from description fields.

Paste your code, then click Convert

TypeScript

How to use this tool?

This online converter harnesses AI to translate OpenAPI/Swagger schema definitions to TypeScript interfaces. Follow these steps:

Paste your OpenAPI schema YAML or JSON components into the input box provided.
Click the "Convert" button to generate TypeScript interfaces from each schema.
View the TypeScript interfaces in the output box, ready to use in your project.

Example: Simple Function

OpenAPI Schema

components:
  schemas:
    User:
      type: object
      required: [id, name]
      properties:
        id:
          type: integer
        name:
          type: string
        email:
          type: string

TypeScript

export interface User {
  id: number;
  name: string;
  email?: string;
}

How to Convert OpenAPI / Swagger to TypeScript

OpenAPI specs define every API endpoint, request body, response schema, and parameter type. Writing TypeScript interfaces manually to match an OpenAPI spec means duplicating every schema definition — and keeping them in sync as the spec evolves.

The OpenAPI to TypeScript converter generates TypeScript interfaces directly from OpenAPI 3.0 or Swagger 2.0 schemas. Paste your spec and get typed interfaces for requests, responses, parameters, and components.

Why Use a OpenAPI / Swagger to TypeScript Converter?

→Keep TypeScript types in sync with your OpenAPI spec without manual updates
→Generate types for all request and response shapes from a single spec file
→Type-check your API client code against the actual API contract
→Eliminate runtime errors from API schema drift

What the OpenAPI to TypeScript Converter Handles

Schema components to interfaces

Request body types

Response body types

Path and query parameters

OpenAPI refs ($ref resolution)

allOf / oneOf / anyOf

Enum schemas to TS enums

Nullable properties

Required vs optional fields

Array schema items

Nested component schemas

Discriminator support

Frequently Asked Questions

What OpenAPI versions are supported?

The converter works with OpenAPI 2.0 (Swagger) and OpenAPI 3.x schemas. Paste the components/schemas (v3) or definitions (v2) section from your spec.

How are required vs optional fields handled?

Fields listed in the 'required' array produce non-optional TypeScript properties. All other fields get the '?' optional modifier.

What OpenAPI types map to TypeScript?

string→string, integer/number→number, boolean→boolean, array→T[], object→interface. $ref references use the referenced type name.

Can I convert a full OpenAPI spec?

For best results, paste just the components/schemas section. Full spec files work too — the converter extracts the schema definitions and generates interfaces for each.

Is the tool free?

Yes, completely free with no account required.

How do I generate TypeScript types from an OpenAPI spec?

Paste your OpenAPI YAML or JSON spec into the converter and click Convert. The tool generates TypeScript interfaces for all schemas under components/schemas, plus types for request and response bodies.

What is the difference between Swagger and OpenAPI?

OpenAPI is the specification standard (version 3.0+). Swagger refers to both the older specification (version 2.0, now called Swagger) and the tooling ecosystem (Swagger UI, Swagger Editor). The converter supports both OpenAPI 3.0 and Swagger 2.0.

How are $ref references resolved in the TypeScript output?

$ref references are resolved to the referenced schema type. Circular references produce recursive TypeScript types. Each component schema becomes a named TypeScript interface.

Can I use the output with fetch or axios?

Yes. The generated TypeScript interfaces type your API function parameters and return values. For example: async function getUser(id: string): Promise<UserResponse> where UserResponse is the generated interface.

What tools auto-generate TypeScript from OpenAPI specs?

openapi-typescript (CLI), swagger-typescript-api, and orval are popular tools for automatically generating TypeScript from OpenAPI specs as part of a build pipeline. The JS2TS converter is useful for quick one-off conversions without setting up a pipeline.