The app uses Xata AI to query ChatGPT with context from the up-to-date docs. This provides more recent information and reduces hallucinations. It uses this high-level algorithm:

  - Pass the question to ChatGPT and ask it to provide keywords
  - Use the Xata search functionality to retrieve the most relevant docs
  - Form a prompt using this context and the question and pass it to ChatGPT
  - This blog post provides more details on the general approach

All the code is open source: https://github.com/xataio/ask-your-stack

The web-crawler can be found here: https://github.com/tsg/xata-crawler

I think this is similar to GitHub Copilot for Docs but I don't have access to it.