openapi-typescript turns OpenAPI 3.0 & 3.1 schemas into TypeScript quickly using Node.js. No Java/node-gyp/running OpenAPI servers necessary.
The code is MIT-licensed and free for use.
Tip:
New to OpenAPI? Speakeasy’s Intro to OpenAPI is an accessible guide to newcomers that explains the “why” and “how” of OpenAPI.
Features
- ✅ Supports OpenAPI 3.0 and 3.1 (including advanced features like discriminators)
- ✅ Generate runtime-free types that outperform old school codegen
- ✅ Load schemas from YAML or JSON, locally or remotely
- ✅ Generate types for even huge schemas within milliseconds
Note: OpenAPI 2.x is supported with versions 5.x and previous
Examples
👀 See examples
Setup
This library requires the latest version of Node.js installed (20.x or higher recommended). With that present, run the following in your project:
npm i -D openapi-typescript typescript
And in your tsconfig.json, to load the types properly:
{
"compilerOptions": {
+ "module": "ESNext", // or "NodeNext"
+ "moduleResolution": "Bundler" // or "NodeNext"
}
}
Highly recommended
Also adding the following can boost type safety:
{
"compilerOptions": {
+ "noUncheckedIndexedAccess": true
}
}
Basic usage
First, generate a local type file by running npx openapi-typescript, first specifying your input schema (JSON or YAML), and where you’d like the --output (-o) to be saved:
# Local schema
npx openapi-typescript ./path/to/my/schema.yaml -o ./path/to/my/schema.d.ts
# 🚀 ./path/to/my/schema.yaml -> ./path/to/my/schema.d.ts [7ms]
# Remote schema
npx openapi-typescript https://myapi.dev/api/v1/openapi.yaml -o ./path/to/my/schema.d.ts
# 🚀 https://myapi.dev/api/v1/openapi.yaml -> ./path/to/my/schema.d.ts [250ms]
Then in your TypeScript project, import types where needed:
import type { paths, components } from "./my-openapi-3-schema"; // generated by openapi-typescript
// Schema Obj
type MyType = components["schemas"]["MyType"];
// Path params
type EndpointParams = paths["/my/endpoint"]["parameters"];
// Response obj
type SuccessResponse =
paths["/my/endpoint"]["get"]["responses"][200]["content"]["application/json"]["schema"];
type ErrorResponse =
paths["/my/endpoint"]["get"]["responses"][500]["content"]["application/json"]["schema"];
From here, you can use these types for any of the following (but not limited to):
- Using an OpenAPI-supported fetch client (like openapi-fetch)
- Asserting types for other API requestBodies and responses
- Building core business logic based on API types
- Validating mock test data is up-to-date with the current schema
- Packaging API types into any npm packages you publish (such as client SDKs, etc.)
📓 Docs
View Docs
