Postman to OpenAPI Converter

A web-based tool that converts Postman Collections (v2.x) to OpenAPI 3.0 Specifications. Built with Next.js, TypeScript, and Tailwind CSS.

Features

• 🔄 Convert Postman Collections to OpenAPI 3.0 Specifications
• 📝 Support for both YAML and JSON output formats
• 📋 One-click copy functionality
• 🎨 Clean and responsive UI
• ⚡ Real-time conversion
• 🛠️ Handles complex Postman collection structures
• 🔍 Detailed error reporting
• 💼 Preserves request metadata (descriptions, examples, etc.)

Supported Conversions

• ✅ Basic request details (URL, method, description)
• ✅ Query parameters
• ✅ Path parameters
• ✅ Headers
• ✅ Request bodies (raw JSON and form-data)
• ✅ Collection folder structure (converted to tags)
• ✅ Authentication schemes (Basic and Digest)

Getting Started

Prerequisites

• Node.js 18.x or later
• npm or yarn

Installation

1. Clone the repository:

git clone https://github.com/yourusername/postman-openapi-converter.git
cd postman-openapi-converter

2. Install dependencies:

npm install
# or
yarn install

3. Run the development server:

npm run dev
# or
yarn dev

4. Open http://localhost:3000 in your browser.

Building for Production

1. Build the application:

npm run build
# or
yarn build

2. Start the production server:

npm start
# or
yarn start

Usage

1. Prepare Your Postman Collection

   • Export your Postman Collection (Collection v2.x format)
   • Copy the JSON content

2. Convert the Collection

   • Paste the Postman Collection JSON into the left textarea
   • Click the "Convert" button
   • Select your preferred output format (YAML or JSON)

3. Use the Result

   • Copy the converted OpenAPI specification using the copy button
   • Use the specification in your OpenAPI tools

Example

Input (Postman Collection):

{
  "info": {
    "name": "Sample API",
    "description": "A sample API collection"
  },
  "item": [
    {
      "name": "Get Users",
      "request": {
        "method": "GET",
        "url": {
          "raw": "https://api.example.com/users",
          "path": ["users"],
          "query": [
            {
              "key": "page",
              "value": "1",
              "description": "Page number"
            }
          ]
        },
        "description": "Get all users"
      }
    }
  ]
}

Output (OpenAPI 3.0):

openapi: 3.0.3
info:
  title: Sample API
  description: A sample API collection
  version: 1.0.0
paths:
  /users:
    get:
      summary: Get Users
      description: Get all users
      parameters:
        - name: page
          in: query
          schema:
            type: string
          example: "1"
          description: Page number
      responses:
        '200':
          description: Successful response

Technical Details

Technologies Used

• Framework: Next.js 14
• Language: TypeScript
• Styling: Tailwind CSS
• UI Components: shadcn/ui
• Icons: Lucide React

Key Components

• PostmanToOpenAPIConverter.tsx: Main component containing the converter logic
• parseUrl(): Handles URL parsing from Postman format
• processParameters(): Processes query parameters, path parameters, and headers
• processRequestBody(): Handles request body conversion
• toYAML(): Converts JavaScript objects to YAML format
• convertToOpenAPI(): Main conversion logic for Postman to OpenAPI

Conversion Process

1. Parses the input Postman Collection JSON
2. Extracts collection metadata (name, description)
3. Processes each request in the collection:
   • Converts URL and path parameters
   • Processes request headers
   • Handles request bodies
   • Maps collection folders to OpenAPI tags
4. Generates the OpenAPI specification
5. Outputs in either YAML or JSON format

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

Limitations

• Only supports Postman Collection Format v2.x
• Limited support for complex authentication schemes
• Does not handle environment variables
• No support for response examples
• Limited support for non-JSON request bodies

Future Improvements

• Support for Postman Collection Format v2.1
• Handle Postman environment variables
• Add support for response examples
• Implement more authentication schemes
• Add batch conversion support
• Add file upload/download functionality
• Implement OpenAPI to Postman conversion
• Add validation for OpenAPI output

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Postman for their amazing API development ecosystem
• OpenAPI Initiative for the OpenAPI Specification
• shadcn/ui for the beautiful UI components

Contact

For any questions or suggestions, please open an issue or contact the maintainers.

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Made with ❤️ by Wisdom Nwokocha and [Prince]