OpenAPI

The OpenAPI adapter reads an OpenAPI 2.0, 3.0, or 3.1 document and converts every schema and operation into Kubb's AST. Every plugin in the build generates code from that AST.

Kubb uses adapterOas() by default. Set it on defineConfig.adapter only to change its options. The options apply to every plugin in the build.

Installation

bun add -d @kubb/adapter-oas

pnpm add -D @kubb/adapter-oas

npm install --save-dev @kubb/adapter-oas

yarn add -D @kubb/adapter-oas

Or run kubb add adapter-oas to install the version the Kubb registry pins and add adapterOas() to kubb.config.ts.

Options worth knowing

• validate checks the spec before parsing and reports each problem as a warning. Turn it off to speed up a large spec. Run kubb validate to list every error.
• dateType sets how date-time, date, and time schemas are represented: ISO strings (the default), strings with or without a timezone offset, or JavaScript Date objects. Pass an object to set each format on its own.
• integerType defaults to 'bigint', which is exact for 64-bit IDs but does not survive JSON.stringify. Choose 'number' for most JSON APIs.
• unknownType and emptySchemaType set the type for schemas Kubb cannot infer and for empty schemas ({}).
• discriminator: 'propagate' writes the discriminator's literal value into each child schema, so each branch is typed precisely.
• enums: 'root' lifts inline enums to reusable top-level schemas, named with enumSuffix (PetStatusEnum).
• server picks the entry in the spec's servers array that becomes the base URL and fills in its variables. It does not change where a generated client sends requests. Use the client plugin's own baseURL for that.
• contentType picks the media type when an operation defines several. Without it, Kubb uses the first JSON media type.

Example

import { defineConfig } from 'kubb/config'
import { adapterOas } from '@kubb/adapter-oas'
import { pluginTs } from '@kubb/plugin-ts'

export default defineConfig({
  input: './petStore.yaml',
  output: { path: './src/gen' },
  adapter: adapterOas({ dateType: 'date', integerType: 'number' }),
  plugins: [pluginTs()],
})