Migrate X -- Automated Flutter & Dart Migration Tool

Migrate X is an open-source, AI-powered Flutter migration tool that automatically upgrades your Flutter/Dart project by fixing deprecated APIs, resolving lint issues, and migrating to Material 3. Upload your project as a zip, get an instant analysis with dart analyze, auto-fix errors using dart fix --apply and an AI agent (Claude), review per-file diffs, and download the upgraded project -- all from a modern web UI.

Whether you're upgrading from Flutter 2 to Flutter 3, migrating to Material 3 theming, replacing deprecated widgets like RaisedButton with ElevatedButton, or fixing primarySwatch to colorSchemeSeed -- Migrate X handles it automatically.

Key Features

• Automated deprecation fixes -- runs dart fix --apply to bulk-fix deprecated Flutter and Dart APIs
• AI-powered error resolution -- an AI agent (Anthropic Claude) analyzes and fixes errors that dart fix can't handle, with real-time progress streaming via SSE
• Static analysis -- runs dart analyze to surface deprecated members, lint warnings, and compile errors
• Per-file diff review -- inspect every change before accepting, with syntax-highlighted side-by-side diffs
• Material 3 migration -- automatically updates useMaterial3, colorSchemeSeed, ColorScheme.fromSeed(), and deprecated color properties
• Widget replacement -- replaces deprecated widgets (RaisedButton -> ElevatedButton, FlatButton -> TextButton, WillPopScope -> PopScope, etc.)
• Zero setup on your machine -- upload a zip, get results in the browser; no local toolchain required
• Light & Dark mode -- fully themed Material 3 UI with theme toggle

Screenshots

Light Mode

Upload

Dark Mode

Landing	Upload

Analyzing	Analysis Results

Applying Fixes	Diff Review

Download

How It Works

1. Upload -- select a zipped Flutter or Dart project from your machine
2. Analyze -- the server runs flutter pub get and dart analyze to detect deprecated APIs, lint violations, and compile errors
3. Auto-Fix -- dart fix --apply handles standard deprecation fixes; an AI agent then tackles remaining errors that require deeper refactoring
4. Review Diffs -- inspect syntax-highlighted, per-file diffs showing every change made; accept or decline individually
5. Download -- export the fully migrated project as a zip

Project Structure

migrate_x/
  backend/          — Dart HTTP API server (shelf + shelf_router)
  frontend/         — Flutter web app with Material 3 UI

Getting Started

Prerequisites

• Dart SDK >= 3.11.0
• Flutter SDK >= 3.41.1

Environment Setup

1. Copy the example environment file in the backend:

cd backend
cp .env.example .env

2. Edit .env to set your desired port and workspace path:

PORT=8080
WORKSPACE_PATH=./workspace

3. Add your Anthropic API key to enable the AI agent for fixing errors that dart fix can't handle:

ANTHROPIC_API_KEY=sk-ant-...

Running the Backend

cd backend
dart pub get
dart run bin/server.dart

The server starts at http://0.0.0.0:8080 by default.

Running the Frontend

cd frontend
flutter pub get
flutter run -d chrome

The app connects to http://localhost:8080 by default. Update the base URL in lib/providers/api_provider.dart if your backend runs elsewhere.

API Endpoints

Method	Path	Description
POST	/upload	Upload a .zip file, returns workspace id
DELETE	/upload/:id	Delete a workspace
POST	/analyze/resolve/:id	Run flutter pub get
GET	/analyze/:id	Run dart analyze on the uploaded project
POST	/migrate/dry-run/:id	Preview fixes without applying
POST	/migrate/apply/:id	Apply fixes (supports SSE streaming)
POST	/download/:id	Download the migrated project as .zip

Tech Stack

• Backend: Dart, shelf, shelf_router, Anthropic Claude API
• Frontend: Flutter Web, Riverpod, Material 3
• Streaming: Server-Sent Events (SSE) for real-time AI agent progress
• Analysis: dart analyze, dart fix

Use Cases

• Upgrading a legacy Flutter 2.x project to Flutter 3.x
• Migrating from Material 2 to Material 3 theming (useMaterial3: true, ColorScheme.fromSeed())
• Bulk-fixing deprecated API calls across a large codebase
• Replacing deprecated widgets (RaisedButton, FlatButton, WillPopScope, accentColor, primarySwatch, etc.)
• Resolving lint warnings and dart analyze errors before a release
• Quick code review of what an automated migration would change, via diff preview

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