Feature Gen

A Dart CLI tool that generates clean-architecture feature modules for Flutter projects from a JSON schema.

Installation

dart pub global activate feature_gen_cli

Usage

feature_gen_cli <feature_name> <schema.json>

Options

Flag	Description
-h, --help	Show usage information
-v, --version	Print the current version

Example

feature_gen_cli user schema.json

Schema Format

The JSON schema defines your feature's API methods and response structure.

{
  "config": {
    "bloc": true,
    "riverpod": false
  },
  "api": {
    "methods": {
      "getUser": {},
      "postSomeData": {
        "body": {
          "name": "string",
          "email": "string",
          "password": "string"
        }
      },
      "updateUser": {
        "body": {
          "name": "string",
          "email": "string"
        }
      },
      "deleteUser": {
        "params": {
          "id": "int"
        }
      }
    }
  },
  "response": {
    "id": 123,
    "name": "string",
    "email": "string",
    "address": {
      "street": "string",
      "city": "string"
    },
    "tags": ["string"]
  }
}

Nested Objects

Feature Gen automatically detects nested JSON objects and lists of objects in your schema. It generates separate Freezed models for these nested structures and handles the mapping between Data Models and Domain Entities recursively.

{
  "response": {
    "user": {
      "id": "int",
      "profile": {
        "bio": "string",
        "avatar_url": "string"
      }
    }
  }
}

Schema Sections

config

The config section determines which state management library to use for the presentation layer. One (and only one) of these must be set to true:

• bloc — Generates BLoC, Event, and State files.
• riverpod — Generates a Notifier class.

api.methods

Each key is a method name (camelCase). A method can optionally define:

• params — URL path parameters
• body — Request body fields
• query — Query string parameters

Methods with at least one of these sections will also get a use-case class generated.

Methods with no sections (e.g. "getUser": {}) generate only the repository/datasource/bloc wiring.

response

Defines the fields for the entity and model classes. Keys are field names, values are types.

To indicate a list response, wrap the response object in an array:

{
  "response": [
    {
      "id": "int",
      "name": "string"
    }
  ]
}

This generates List<Entity> return types across all layers (repository, datasource, usecase, bloc state, riverpod notifier).

Supported Types

Schema Value	Dart Type
"string"	String
"int"	int
"double"	double
"bool"	bool
"list"	List<dynamic>
"map"	Map<String, dynamic>
{ ... }	CustomModel
[{ ... }]	List<CustomModel>

You can also use actual JSON values (e.g. 123 → int, "hello" → String). Nested objects are automatically lifted into their own classes named after the key (PascalCase).

Generated Structure

Running feature_gen_cli user schema.json produces:

lib/
├── core/
│   └── di/
│       └── injector.dart
└── features/user/
├── data/
│   ├── datasources/
│   │   └── user_remote_datasource.dart
│   ├── models/
│   │   └── user_model.dart
│   └── repositories/
│       └── user_repository_impl.dart
├── domain/
│   ├── entities/
│   │   └── user_entity.dart
│   ├── repositories/
│   │   └── user_repository.dart
│   └── usecases/
│       ├── get_user_usecase.dart
│       ├── post_some_data_usecase.dart
│       ├── update_user_usecase.dart
│       └── delete_user_usecase.dart
└── presentation/
    ├── bloc/ (if enabled)
    │   ├── user_bloc.dart
    │   ├── user_event.dart
    │   └── user_state.dart
    ├── riverpod/ (if enabled)
    │   └── user_notifier.dart
    └── screen/
        └── user_screen.dart

If any method has params/body/query, a shared base use-case is also created at:

lib/features/shared/usecase/base_usecase.dart

What It Does Automatically

1. Checks & installs dependencies — Adds missing packages (flutter_bloc, flutter_riverpod, freezed, get_it, injectable, etc.) to the target project's pubspec.yaml based on your config.
2. Generates feature files — Renders all Dart files from Mustache templates following clean architecture.
3. Runs build_runner — Triggers code generation for Freezed models and JSON serialization.
4. Formats code — Runs dart format on the generated feature directory.

Required Dependencies

These are automatically added if missing:

Runtime: get_it, injectable, equatable, freezed_annotation, json_annotation, flutter_bloc (if bloc: true), flutter_riverpod (if riverpod: true)

Dev: build_runner, injectable_generator, freezed, json_serializable

Project Structure

feature_gen/
├── bin/feature_gen_cli.dart        # CLI entry point
├── lib/
│   ├── feature_gen.dart        # Pipeline orchestrator
│   ├── parser.dart             # JSON schema parser & context builder
│   ├── generator.dart          # Directory creation & template rendering
│   ├── command_runner.dart     # Shell command execution (deps, build, format)
│   ├── command_helper.dart     # Styled console output (errors, success, warnings)
│   ├── types.dart              # Data models (Schema, Context, etc.)
│   ├── string_extension.dart   # Case-conversion utilities
│   ├── yaml_helper.dart        # pubspec.yaml reader
│   └── template/               # Mustache template files
└── pubspec.yaml

License

MIT