---
title: "dart_openapi_generator"
description: "Native-Dart, zero-Java OpenAPI 3.x → Dart code generator for Flutter and Dart."
---

Reads an OpenAPI 3.x spec (YAML or JSON, local file or HTTPS URL) and generates idiomatic
Dio-based model classes and API client services via `build_runner`. No JVM. No Mustache.
Generated code looks like a developer wrote it by hand.

## Features

- Generates `final class` model classes with `fromJson`, `toJson`, `copyWith`, `==`, and `hashCode`
- Generates Dart `enum` types with `fromJson`/`toJson` switch expressions
- Generates `sealed class` hierarchies for `oneOf` schemas with a discriminator
- Flattens `allOf` schemas into a single merged class
- Handles `additionalProperties` (typed or untyped)
- Generates Dio-based service classes from OpenAPI paths — one file per tag
- Generates an aggregator client class with static auth-helper factories (Bearer, API key header/query, HTTP Basic)
- Supports `LocalSpec` (local YAML/JSON file) and `RemoteSpec` (HTTPS URL with optional request headers)
- MD5-keyed cache — skips unchanged specs for fast incremental builds
- Supports OpenAPI 3.0, 3.1, and 3.2 (including `in: querystring` and `additionalOperations`)
- Zero runtime dependencies in the consumer's tree — `dart_openapi_generator` is a dev dependency

## Installation

```yaml title="pubspec.yaml"
dependencies:
  dart_openapi_generator_annotations: ^0.1.0
  dio: ^5.0.0

dev_dependencies:
  dart_openapi_generator: ^0.1.0
  build_runner: ^2.4.0
```

## Get Started

Follow the [Getting Started guide](/getting-started) to go from zero to a working API client.

See the [Annotation Reference](/annotation-reference) for every `@OpenApiGenerator` field.