One dependency-free TypeScript file, with types for every operation and a small fetch-based runtime.
QUERY operations, sequential media types, multi-file documents, and JSON Schema 2020-12. oasis-gen also accepts OpenAPI 3.0 and 3.1 documents.
status narrows data to the declared response. Statuses that the document does not declare stay in the type. Request types respect readOnly and writeOnly.
The output is a single TypeScript file that runs anywhere fetch is available. There is no runtime package to install and nothing to configure.
npx oasis-gen openapi.yaml -o src/api.tsimport { createClient } from "./api.ts";
const api = createClient({ baseUrl: "https://api.example.com" });
const res = await api.GET("/pets/{petId}", { path: { petId: 1 } });
if (res.status === 200) {
res.data.name; // typed from the 200 response
} else if (res.status === 404) {
res.data.title; // typed from the 404 response
}