capricorn

A capability URL HTTP server that allows creating secure, transformed request forwarding.

Features

• Create capability URLs that forward requests to destination URLs
• Transform requests using custom JavaScript functions
• Secure access through randomly generated capability IDs

Usage

Create a New Capability

POST to /create-capability with a JSON body containing:

• destinationUrl: The URL where requests should be forwarded
• transformFunction: A JavaScript function that transforms the request

Example:

{
  "destinationUrl": "https://api.example.com/data",
  "transformFunction": "function(req) { return { headers: { 'X-Custom': 'value' }, body: req.body }; }"
}

The server will return a capability URL. When requests are made to this URL, they will be:

1. Transformed using your provided function
2. Forwarded to the destination URL
3. Responses will be returned to the original requester

Using Capability URLs

Simply make HTTP requests to the generated capability URL. The server will:

1. Transform the request using your function
2. Forward it to the destination
3. Return the response

Security

Each capability URL contains a unique, random identifier. Only requests with valid capability IDs will be processed.

Setup

1. Install dependencies:

npm install

2. Set up PostgreSQL database:

# Create database (run this once)
createdb capricorn

# If you get permissions errors:
# sudo -u postgres createdb capricorn

3. Set environment variables:

• Create .env file with:

DATABASE_URL=postgres://localhost:5432/capricorn

4. Start the server:

npm start