CASL GraphQL Middleware

A middleware solution for integrating CASL authorization with GraphQL servers, with specific support for Postgraphile and Nuxt GraphQL Server.

Features

• CASL integration with GraphQL resolvers
• Framework-specific helpers for Postgraphile and Nuxt
• Type-safe ability definitions
• Support for field-level permissions
• Ability to combine multiple authorization rules

Installation

pnpm add @stonecrop/casl-middleware

Basic Usage

Core Middleware

import { createCaslMiddleware } from '@stonecrop/casl-middleware'

const middleware = createCaslMiddleware({
  subjectMap: {
    User: 'User',
    Item: 'Item'
  },
  fieldPermissions: {
    'Item.price': [{ action: 'read', subject: 'item' }]
  }
})

Postgraphile Integration

// graphile.config.js
import { pglCaslPlugin } from '@stonecrop/casl-middleware'
import { postgraphile } from 'postgraphile'

export default {
  pgServices: [
    makePgService({
      connectionString: 'postgres://testuser:testpass@postgres:5432/testdb',
      schemas: ['public'],
    }),
  ],
  plugins: [pglCaslPlugin],
}

Testing Abilities in GraphiQL

Create an ability:

mutation CreateAbility {
  createAbility(input: {
    userId: "123",
    roles: ["admin"]
  }) {
    success
    ability
    message
  }
}

Test protected queries:

query GetSecretData {
  getSecretData {
    id
    content
  }
}

Development

Prerequisites

• Node.js >= 20
• pnpm
• Docker and Docker Compose

Local Development

1. Clone the repository:

git clone <repository-url>
cd casl-middleware

2. Install dependencies:

pnpm install

3. Run the Postgraphile example:

pnpm dev:postgraphile

Project Structure

.
├── examples/
│   └── postgraphile/        # Postgraphile example implementation
├── src/
│   ├── middleware/         # Core CASL middleware
│   ├── types/             # TypeScript types
│   └── index.ts           # Main exports

Framework Support

Postgraphile

• Implements CASL as a Postgraphile plugin
• Supports ability creation and management
• Integrates with Postgraphile's schema extension system

Nuxt GraphQL Server

• Provides middleware for Nuxt's GraphQL module
• Handles ability creation on request
• Integrates with Nuxt's context system

Contributing

1. Fork the repository
2. Create your feature branch
3. Commit your changes
4. Push to the branch
5. Create a new Pull Request

License

MIT License

TODOs

• [ ] Add test suite
• [ ] Add more framework integrations
• [ ] Implement ability persistence
• [ ] Add more examples for different use cases
• [ ] Add documentation for advanced usage scenarios