title: Are there any open-source check-in / check-out systems?
body: <p>I work for a building where people check in when they arrive, and are supposed to check out when they leave. It's necessary for:</p>
  
  <ul>
  <li>Fire regulations</li>
  <li>It tells the receptionist whether the visitor's membership is valid</li>
  <li>The marketing team want to use it for CRM</li>
  </ul>
  
  <p>At present, the visitor checks in by scanning their membership card with a barcode reader, and speaks to the receptionist to check out. However, this process is really inefficient for both visitors and the receptionist, and so the data is usually quite inaccurate.</p>
  
  <p>I'm looking for solutions that are a bit more robust. Obviously, I could build something, but I'm wondering if there is some kind of open source solution already out there. It would need to have an API to integrate with the other existing systems. </p>