fake-api-cli

✨ Features

• ⚡ Generate complete REST APIs in seconds
• 📦 Zero database setup
• 👤 Built-in generators for common resources
• 🧩 Custom schema-based resource generation
• 🔗 Resource references (@users.id)
• 🏗 Nested objects
• 📚 Arrays
• 💾 Automatic JSON persistence
• 🔍 Filtering
• 📄 Pagination
• ↕ Sorting
• 🔎 Search
• 🎯 Field selection
• 🔄 Full CRUD support
• 🖥 Simple CLI
• 📖 Swagger UI
• 📝 Written entirely in TypeScript

Why fake-api?

Frontend developers often need an API before the backend is ready.

Instead of manually creating JSON files or spinning up a database, fake-api generates a realistic REST API with configurable resources, relationships, and fake data.

Perfect for:

• Frontend development
• UI prototyping
• Hackathons
• Portfolio projects
• Testing REST clients
• Learning API integration

Installation

Install globally

npm install -g fake-api-cli

Or use directly with NPX

npx fake-api-cli start

Quick Start

Create a configuration file.

export default {
  port: 3000,

  persistence: true,

  database: "./fake-api-db.json",

  resources: {
    users: {
      count: 100,
      schema: {
        name: "person.fullName",
        email: "internet.email",
        city: "location.city",
      },
    },
  },
};

Start the server.

fake-api start

Output

✔ Fake API Server Started

URL:
http://localhost:3000

Resources:
• /users

Swagger:
/docs

Now open

http://localhost:3000/users

You'll instantly have a fully working REST API.

Example Response

[
  {
    "id": 1,
    "name": "John Doe",
    "email": "[email protected]",
    "city": "London"
  },
  {
    "id": 2,
    "name": "Alice Smith",
    "email": "[email protected]",
    "city": "Paris"
  }
]

Supported HTTP Methods

| Method | Endpoint | Description | | ------ | ------------ | ----------------------- | | GET | /users | Get all records | | GET | /users/:id | Get a single record | | POST | /users | Create a record | | PUT | /users/:id | Replace a record | | PATCH | /users/:id | Update part of a record | | DELETE | /users/:id | Delete a record |

Built-in Resources

Out of the box, fake-api includes generators for:

• Users
• Products
• Posts

Example

resources: {
  users: {
    count: 100,
  },

  products: {
    count: 50,
  },

  posts: {
    count: 25,
  },
}

Need something else?

Just define a schema and fake-api generates it automatically.

Custom Schema Generation

Create completely custom resources without writing generators.

resources: {
  books: {
    count: 5,

    schema: {
      title: "book.title",
      author: "person.fullName",
      pages: "number.int(100,500)",
    },
  },
}

Output

{
  "id": 1,
  "title": "The Hobbit",
  "author": "Jane Doe",
  "pages": 341
}

Nested Objects

schema: {
  name: "person.fullName",

  address: {
    city: "location.city",
    country: "location.country",
  },
}

Result

{
  "name": "John",

  "address": {
    "city": "London",
    "country": "United Kingdom"
  }
}

Arrays

skills: [
  "helpers.arrayElement(React,Node,Go)",
  "helpers.arrayElement(TypeScript,Rust,Python)"
]

Produces

{
  "skills": [
    "React",
    "TypeScript"
  ]
}

🔗 Resource References

Resources can reference records from other resources using the @resource.field syntax.

Example

resources: {
  users: {
    count: 100,
    schema: {
      name: "person.fullName",
    },
  },

  posts: {
    count: 200,
    schema: {
      title: "lorem.sentence",
      userId: "@users.id",
    },
  },
}

Generated output

{
  "id": 1,
  "title": "My First Post",
  "userId": 42
}

References are randomly selected from existing records.

They can also be used inside arrays.

friends: [
  "@users.id",
  "@users.id"
]

Result

{
  "friends": [14, 87]
}

🔍 Query Parameters

Every generated resource automatically supports powerful query operations.

Pagination

GET /users?page=1&limit=10

Sorting

Ascending

GET /users?sort=name

Descending

GET /users?sort=-name

Multiple fields

GET /users?sort=city,-name

Filtering

Equality

GET /users?city=London

Not equal

GET /users?city_ne=London

Greater than

GET /products?price_gt=100

Greater than or equal

GET /products?price_gte=100

Less than

GET /products?price_lt=500

Less than or equal

GET /products?price_lte=500

IN operator

GET /users?role_in=Admin,Manager

Search

Search across supported fields.

GET /users?search=john

Field Selection

Return only selected fields.

GET /users?fields=id,name,email

Response

[
  {
    "id": 1,
    "name": "John Doe",
    "email": "[email protected]"
  }
]

💾 Persistence

When persistence is enabled, all changes are automatically written to a JSON database.

export default {
  persistence: true,

  database: "./fake-api-db.json",
}

Supported operations:

• POST
• PUT
• PATCH
• DELETE

Changes are immediately persisted to disk.

📖 Swagger UI

Every server exposes interactive API documentation.

http://localhost:3000/docs

Swagger allows you to:

• Explore endpoints
• Execute requests
• View responses
• Test CRUD operations

No additional configuration required.

🖥 CLI

Start the server

fake-api start

Using NPX

npx fake-api-cli start

Development

npm run dev -- start

Build

npm run build

⚙ Configuration

A typical configuration file looks like this.

export default {
  port: 3000,

  delay: 0,

  persistence: true,

  database: "./fake-api-db.json",

  auth: false,

  resources: {
    users: {
      count: 100,

      schema: {
        name: "person.fullName",
        email: "internet.email",
        city: "location.city",
      },
    },
  },
}

📁 Project Structure

fake-api/

├── src/
│   ├── cli/
│   ├── config/
│   ├── controllers/
│   ├── database/
│   ├── generators/
│   ├── query/
│   ├── routes/
│   ├── server/
│   ├── services/
│   ├── types/
│   └── utils/
│
├── dist/
├── package.json
└── README.md

🛣 Roadmap

v0.x

• ✅ CRUD API
• ✅ Query Engine
• ✅ Built-in generators
• ✅ Custom schema generation
• ✅ Nested objects
• ✅ Arrays
• ✅ Resource references
• ✅ Persistence
• 🚧 Request validation
• 🚧 Better Swagger generation
• 🚧 Seeded data generation
• 🚧 API authentication
• 🚧 Response delay simulation

v1.0

• Stable API
• Production-ready documentation
• Improved CLI
• Comprehensive testing
• OpenAPI improvements

🤝 Contributing

Contributions are welcome.

If you'd like to improve fake-api, feel free to:

1. Fork the repository
2. Create a new branch
3. Commit your changes
4. Open a Pull Request

Bug reports, feature requests, and discussions are always appreciated.

📄 License

This project is licensed under the MIT License.

See the LICENSE file for details.

⭐ Support the Project

If you find fake-api useful, consider giving the repository a ⭐ on GitHub.

It helps the project reach more developers and motivates future development.

Made with ❤️ by Pabitra Maity