# Introducing json2dartgen: Generate Dart Models from JSON Effortlessly 🚀


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I'm excited to announce the release of **[json2dartgen](https://pub.dev/packages/json2dartgen)** — a brand new CLI tool to make working with JSON in Dart and Flutter projects much easier.

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## Why json2dartgen?

If you’ve ever worked with APIs in Flutter, you know the pain: you get a massive JSON response, and now you need Dart models with `fromJson`, `toJson`, and maybe a `copyWith` method too. Tools like quicktype.io are great, but they often struggle with very large JSONs or don’t quite integrate with your code style.

That’s why I built **json2dartgen**:

* Works directly from the command line
* Handles **large JSON files** with ease
* Fully supports `json_serializable`
* Generates **clean, idiomatic Dart code**

---

## Features

* ✅ `fromJson` / `toJson` using `json_serializable`
* ✅ Automatic `copyWith` generation
* ✅ Optional snake\_case → camelCase conversion
* ✅ Output models as a single file or multiple files
* ✅ Configurable via CLI flags
* ✅ Lightweight, fast, and built for Dart devs

---

## Installation

Install globally via Dart:

```bash
dart pub global activate json2dartgen
```

---

## Usage

```bash
json2dartgen <input.json> [options]
```

### Options

| Flag               | Description                                                     |
| ------------------ | --------------------------------------------------------------- |
| `-c, --camel-case` | Convert snake\_case JSON keys to camelCase field names          |
| `-o, --output-dir` | Output directory for `.dart` files (default: current directory) |
| `-h, --help`       | Show usage instructions                                         |

---

## Example

Input JSON:

```json
{
  "building_id": 1130,
  "floor_count": 5,
  "location_name": "North Wing"
}
```

Generated Dart model:

```dart
import 'package:json_annotation/json_annotation.dart';

part 'root.g.dart';

@JsonSerializable()
class Root {
  @JsonKey(name: 'building_id')
  final int buildingId;

  @JsonKey(name: 'floor_count')
  final int floorCount;

  @JsonKey(name: 'location_name')
  final String locationName;

  const Root({
    required this.buildingId,
    required this.floorCount,
    required this.locationName,
  });

  Root copyWith({
    int? buildingId,
    int? floorCount,
    String? locationName,
  }) {
    return Root(
      buildingId: buildingId ?? this.buildingId,
      floorCount: floorCount ?? this.floorCount,
      locationName: locationName ?? this.locationName,
    );
  }

  factory Root.fromJson(Map<String, dynamic> json) => _$RootFromJson(json);
  Map<String, dynamic> toJson() => _$RootToJson(this);
}
```

---

## Try It Out

You can get started right now:

```bash
dart pub global activate json2dartgen
json2dartgen your_api_response.json --camel-case --output-dir lib/models
```

---

## What’s Next?

This is just the beginning 🚀. Future updates will include:

* More configuration options
* Better error messages
* Improved type inference
* Flutter-specific utilities

If you try it out, I’d love to hear your feedback and feature requests.

👉 Check it out here: [json2dartgen on pub.dev](https://pub.dev/packages/json2dartgen)

Happy coding! 💙