scalar-ui-server

A CLI tool to serve OpenAPI documentation with Scalar UI using Bun runtime.

Features

• 🚀 Serve OpenAPI/Swagger documentation instantly
• 📄 Support for local files and remote URLs
• 🎨 Beautiful Scalar UI interface
• 🔧 Custom port configuration
• 🌐 Built-in CORS support
• 🔄 Proxy support for API testing
• ⚡ Powered by Bun for blazing-fast performance

Installation

Using bunx (recommended)

No installation required! Just run:

bunx scalar-ui-server ./openapi.yaml

Using npx

npx scalar-ui-server ./openapi.yaml

Global installation

bun install -g scalar-ui-server
# or
npm install -g scalar-ui-server

Usage

scalar-ui-server <openapi-source> [options]

Arguments

• <openapi-source> - Path or URL to your OpenAPI specification file (YAML or JSON)

Options

• -p, --port <port> - Port number to run the server on (default: 3001)
• -h, --help - Show help message

Examples

Local Files

# Serve OpenAPI documentation on default port (3001)
scalar-ui-server ./openapi.yaml

# Serve on custom port
scalar-ui-server ./openapi.json --port 8080

# Short form
scalar-ui-server ./api-spec.yaml -p 3000

# Using bunx (no installation needed)
bunx scalar-ui-server ./openapi.yaml

# Using npx
npx scalar-ui-server ./openapi.yaml --port 4000

Remote URLs

# Serve from a remote URL
scalar-ui-server https://petstore3.swagger.io/api/v3/openapi.json

# Remote URL with custom port
scalar-ui-server https://api.example.com/openapi.yaml --port 8080

# Using bunx with URL
bunx scalar-ui-server https://petstore3.swagger.io/api/v3/openapi.json

Development

Install dependencies

bun install

Run locally

bun run start ./openapi.yaml

Run with custom port

bun run index.ts ./openapi.yaml --port 8080

Requirements

• Bun v1.0.0 or higher (for direct execution)
• Node.js v18+ (for npx execution)

License

This project was created using bun init in bun v1.3.0. Bun is a fast all-in-one JavaScript runtime.