🧵 TypeWeaver

Stop manually syncing types between your backend and frontend.

Auto-generate TypeScript interfaces from your ORM schemas in real-time.

🔥 The Problem

Full-stack TypeScript developers face a daily problem:

// Backend: Update User model
const userSchema = new Schema({
  name: String,
  email: String,
  phoneNumber: String, // ← NEW FIELD
});

// Frontend: Types are now OUT OF SYNC ❌
interface User {
  name: string;
  email: string;
  // Missing phoneNumber!
}

// Result: Runtime bugs that TypeScript should have caught

The consequences:

• ⏰ 30+ minutes per week manually copying types
• 🐛 Type mismatches cause production bugs
• 🔄 Constant context switching between backend/frontend
• 😤 Forgotten updates slip through code reviews

✨ The Solution

# One-time setup
npx typeweaver init

# Generate types once
npx typeweaver generate

# Or watch mode (auto-sync on every change)
npx typeweaver watch

That's it. Your frontend types stay in sync automatically.

🚀 Quick Start

Run locally (Windows PowerShell)

If you're on Windows and using PowerShell, here are copy/paste-friendly commands:

# install deps
npm install

# interactive setup
npx typeweaver init

# generate types once
npx typeweaver generate

# watch mode
npx typeweaver watch

# run tests
npm test

# run dev CLI
npm run dev

Installation

npm install -D typeweaver

Setup (Interactive)

npx typeweaver init

This creates typeweaver.config.json:

{
  "orm": "prisma",
  "schemaPath": "./prisma/schema.prisma",
  "outputPath": "./types",
  "outputMode": "single"
}

Generate Types

# One-time generation
npx typeweaver generate

# Watch mode (auto-regenerate on changes)
npx typeweaver watch

📋 Features

✅ Supported ORMs

| ORM | Status | Description | | ------------- | -------------- | ------------------------- | | Prisma | ✅ Ready | Parse schema.prisma files | | Mongoose | ✅ Ready | Parse Schema definitions | | TypeORM | 🚧 Coming Soon | Parse decorators | | Sequelize | 🚧 Coming Soon | Parse models |

✨ Key Features

• Zero Migration - Works with your existing code
• Real-Time Sync - Watch mode updates types instantly (<500ms)
• Safe Writes - Automatic backups before overwriting
• Multi-ORM - Prisma, Mongoose, and more
• Flexible Output - Single file or one file per model
• Type-Safe - Handles complex types, enums, arrays, references
• Smart Detection - Auto-detects your ORM

📖 Usage Examples

Prisma

// schema.prisma
model User {
  id    String @id @default(cuid())
  email String @unique
  name  String
  age   Int?
  posts Post[]
}

model Post {
  id      String @id
  title   String
  content String?
  author  User   @relation(fields: [authorId], references: [id])
  authorId String
}

Generated TypeScript:

// types/index.ts
export interface User {
  id: string;
  email: string;
  name: string;
  age?: number | null;
  posts: string[];
}

export interface Post {
  id: string;
  title: string;
  content?: string | null;
  author: string;
  authorId: string;
}

Mongoose

// models/User.js
const userSchema = new Schema({
  name: { type: String, required: true },
  email: { type: String, required: true },
  age: Number,
  role: { type: String, enum: ["user", "admin"] },
  posts: [{ type: Schema.Types.ObjectId, ref: "Post" }],
});

Generated TypeScript:

// types/index.ts
export interface User {
  name: string;
  email: string;
  age?: number | null;
  role: "user" | "admin";
  posts: string[];
}

⚙️ Configuration

Config File (typeweaver.config.json)

{
  "orm": "auto",
  "modelsPath": "./models",
  "schemaPath": "./prisma/schema.prisma",
  "outputPath": "./types",
  "outputMode": "single",
  "watch": false,
  "includeComments": true,
  "exclude": ["**/node_modules/**", "**/*.test.{js,ts}"]
}

Configuration Options

| Option | Type | Default | Description | | ----------------- | -------- | -------------------------- | ---------------------------------------- | | orm | string | "auto" | ORM to use: auto, prisma, mongoose | | modelsPath | string | "./models" | Path to Mongoose models | | schemaPath | string | "./prisma/schema.prisma" | Path to Prisma schema | | outputPath | string | "./types" | Where to generate types | | outputMode | string | "single" | single file or separate files | | watch | boolean | false | Enable watch mode | | includeComments | boolean | true | Include JSDoc comments | | readonly | boolean | false | Generate readonly properties | | exclude | string[] | [] | Files to exclude |

🖥️ CLI Commands

init

Initialize configuration with interactive prompts.

npx typeweaver init

Options:

• --force - Overwrite existing config

generate

Generate types once from your schemas.

npx typeweaver generate

Options:

• --config <path> - Custom config file path
• --output <path> - Override output path
• --dry-run - Preview without writing
• --verbose - Show detailed output

watch

Watch schemas and auto-generate types on changes.

npx typeweaver watch

Options:

• --config <path> - Custom config file path
• --output <path> - Override output path

verify

Verify types are in sync with schemas (great for CI/CD).

npx typeweaver verify

info

Show current configuration.

npx typeweaver info

clean

Remove all generated type files.

npx typeweaver clean

Options:

• --dry-run - Preview files to be deleted

🎯 Use Cases

1. MERN Stack Development

backend/
  models/
    User.js
    Post.js
  typeweaver.config.json

frontend/
  types/  ← Auto-generated
    index.ts

2. Monorepo with Multiple Frontends

{
  "orm": "prisma",
  "schemaPath": "./backend/schema.prisma",
  "outputPath": [
    "../web-app/src/types",
    "../mobile-app/src/types",
    "../admin-dashboard/src/types"
  ]
}

3. API Development

Generate types for your TypeScript SDK:

api/
  schema.prisma
  typeweaver.config.json → outputs to sdk/types/
sdk/
  types/
    index.ts  ← Auto-generated

🔧 Advanced Usage

Custom Type Mapping

{
  "customTypeMap": {
    "ObjectId": "string",
    "Mixed": "Record<string, any>"
  }
}

Multiple Output Paths

{
  "outputPath": ["./frontend/types", "./mobile/types"]
}

Exclude Patterns

{
  "exclude": ["**/node_modules/**", "**/*.test.js", "**/deprecated/**"]
}

🆚 Comparison

| Solution | Zero Migration | Real-Time | No Stack Lock-in | Setup Time | | ------------------- | --------------------- | --------------------- | ---------------- | ---------- | | typeweaver | ✅ | ✅ (<500ms) | ✅ | <1 min | | GraphQL Codegen | ❌ (Requires GraphQL) | ⚠️ (Slow) | ❌ | Weeks | | tRPC | ❌ (Full rewrite) | ✅ | ❌ | Days | | Manual npm packages | ✅ | ❌ (10+ min) | ✅ | Hours | | Monorepo sharing | ⚠️ (Complex) | ⚠️ (Requires rebuild) | ✅ | Days |

🤝 Contributing

Contributions are welcome! See CONTRIBUTING.md.

Development Setup

# Clone repo
git clone https://github.com/yourusername/type-bridge.git
cd type-bridge

# Install dependencies
npm install

# Run tests
npm test

# Test CLI locally
node bin/typeweaver.js generate --help

📝 License

MIT © TypeWeaver Contributors

🙏 Acknowledgments

• Inspired by the pain of manual type synchronization
• Built for the full-stack TypeScript community
• Thanks to all contributors and early adopters

📞 Support

• 🐛 Issues: GitHub Issues
• 💬 Discussions: GitHub Discussions
• 📧 Email: [email protected]

🗺️ Roadmap

✅ v1.0.0 (Current - November 2025)

• ✅ Prisma support
• ✅ Mongoose support
• ✅ Circular reference detection
• ✅ Nested object support
• ✅ Verification command
• ✅ Better type mappings
• ✅ Production ready!

v1.1.0 (Planned)

• [ ] Custom type mappings configuration
• [ ] Field transformations (removeFields, renameFields)
• [ ] Better error messages with line numbers

v1.2.0 (Planned)

• [ ] DTO generation (CreateDto, UpdateDto, ResponseDto)
• [ ] TypeORM support
• [ ] Sequelize support

v1.3.0+ (Future)

• [ ] Zod schema generation
• [ ] GraphQL schema generation
• [ ] React Query hooks generation
• [ ] tRPC router generation
• [ ] VS Code extension

Made with ❤️ for full-stack TypeScript developers

Stop wasting time on type synchronization. Start using typeweaver today! 🚀