OpenAPI / Swagger to TypeScript & Zod Converter

How to Convert OpenAPI / Swagger Schemas to TypeScript

OpenAPI / Swagger -> TypeScript Converter parses standard Swagger (v2) and OpenAPI (v3) schemas in JSON or YAML format and instantly outputs strongly-typed, fully annotated TypeScript models, Zod validation schemas, and fully-typed API clients.

1. Supported Output Targets

• Types / Interfaces: Clean, pure type annotations for every request payload, parameter, and response object.
• Zod Validation Schemas: Runtime Zod schemas (z.object({...})) automatically mapping data types, string validations (email, uuid, url), numerical bounds, array items, and optional properties.
• API SDK Clients: Ready-to-use typesafe API clients using either vanilla browser fetch or axios that map all path parameters, headers, queries, bodies, and responses directly into robust, fully annotated asynchronous class methods.

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Key Features

• YAML & JSON Parser: Native client-side support for both Swagger v2/OpenAPI v3 formats in JSON and YAML without external servers.
• Bi-Directional Spec Loaders: Paste raw code directly or fetch public schemas directly from endpoints using their remote URLs.
• Custom Mapping Controls: Flexible configuration to enforce camelCase casing, attach descriptions as JSDoc comments, force all fields to optional, or append readonly tags.
• Intelligent References & Objects: Resolves deep path schemas, references ($ref), nested arrays, unions (anyOf/oneOf), and intersections (allOf).

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Common Use Cases

• Contract-First Development: Translating backend API specifications directly into clean, up-to-date type signatures for frontend applications.
• Automated Client SDK Generation: Generating typed SDKs for single-page React or Next.js clients to remove manual fetch boilerplate.
• Runtime Validation Guardrails: Creating Zod schemas corresponding to database definitions to secure client forms and Express API routing layers.
• Quick Schema Discovery: Importing third-party developer APIs (e.g. Stripe, SendGrid) to browse their data structures as strongly-typed interfaces.

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Frequently Asked Questions

Does this tool send my spec to a remote server?

No! All OpenAPI parsing, resolving, and TypeScript code generation runs 100% locally in your browser. No API keys, server credentials, or schemas are shared.

How are Swagger circular dependencies handled?

For TypeScript types, interfaces and types can reference each other natively. For Zod, circular references are wrapped in z.lazy(() => ...) to avoid runtime definition errors.

Does this support OpenAPI v3.1 schemas?

Yes! The parser processes standard components and objects mapping to types. Standard OpenAPI 3.0 and 3.1 syntax properties translate cleanly into core Typescript types.