---
url: /adapters/adapter-oas.md
description: >-
  Reads an OpenAPI 2.0, 3.0, or 3.1 spec and converts every schema and operation
  into the AST that Kubb plugins generate from, so one adapter feeds the whole
  build.
---

# @kubb/adapter-oas

The OpenAPI adapter sits between your spec and every Kubb plugin. It reads the spec from `input`, whether that is a file, a URL, inline content, or a parsed object, validates it, and converts each schema and operation into Kubb's universal AST that downstream plugins consume.

Configure it once on `defineConfig`. Its choices for date representation, integer width, and server URL apply to every plugin in the build.

See [Options](/adapters/adapter-oas/reference/options) for the full configuration reference.

## Installation

::: code-group

```shell [bun]
bun add -d @kubb/adapter-oas
```

```shell [pnpm]
pnpm add -D @kubb/adapter-oas
```

```shell [npm]
npm install --save-dev @kubb/adapter-oas
```

```shell [yarn]
yarn add -D @kubb/adapter-oas
```

:::

## Dependencies

`@kubb/adapter-oas` has no plugin dependencies. Every other Kubb plugin depends on it, not the other way around.

## Example

::: code-group

```typescript twoslash [kubb.config.ts]
import { defineConfig } from 'kubb'
import { adapterOas } from '@kubb/adapter-oas'
import { pluginTs } from '@kubb/plugin-ts'

export default defineConfig({
  input: './petStore.yaml',
  output: { path: './src/gen' },
  adapter: adapterOas({
    validate: true,
    server: { index: 0, variables: { env: 'prod' } },
    discriminator: 'propagate',
    enums: 'root',
    dateType: 'date',
    integerType: 'number',
    unknownType: 'unknown',
    emptySchemaType: 'unknown',
    enumSuffix: 'enum',
  }),
  plugins: [pluginTs()],
})
```

:::

## See also

* [Changelog](https://github.com/kubb-labs/kubb/blob/main/packages/adapter-oas/CHANGELOG.md)