Problem Description

We need a library that lets websites talk to DigitalPersona 4500 fingerprint readers using just the browser's built-in WebUSB API. While we have a suggested approach using libfprint as inspiration, we're open to any solution that works directly in modern browsers without requiring installations.

Important Note: You don't need to own a fingerprint reader! We will test your solution with our hardware and work with you to ensure everything functions correctly.

What We Need

1. A JavaScript/WebAssembly library that:

   • Uses WebUSB to communicate with fingerprint readers
   • Captures fingerprint images
   • Returns the images as standard web formats (Blob/ArrayBuffer)
   • Works in modern browsers

2. Basic documentation showing:

   • How to use the library
   • Example code
   • Setup instructions

Recommended Resources

• WebUSB API Guide
• Guide for porting USB code to WebUSB
• libfprint example image capture code

Technical Details

The library needs to:

• Connect to DigitalPersona 4500 readers via WebUSB
• Capture fingerprint images
• Handle basic error cases
• Work without any drivers or installations

Testing Process

1. You develop and test the WebUSB communication code
2. We test your code with actual fingerprint readers
3. We work together to resolve any hardware-specific issues
4. Final testing and verification

What Success Looks Like

1. Library works reliably with DigitalPersona 4500 readers
2. Code is clean and well-documented
3. Includes basic error handling
4. Has example code showing usage
5. Works in modern browsers supporting WebUSB

Questions?

Feel free to ask about any part of this bounty. We're happy to clarify requirements or discuss different approaches to solving this challenge.