The app uses my fork of the Swift SDK for OpenAI's Realtime API package here to support both WebRTC and WebSocket.
If you need to add the package in your own app (or readd to this app), open the project in Xcode, select your project > Package Dependencies, click the +, enter https://github.com/jeffxtang/swift-realtime-openai.git (or https://github.com/m1guelpf/swift-realtime-openai after the PR is merged), and click Add Packages.
Credit also to the WebRTC example in the OpenAIOSRealtimeAPIDemo repo here.
To run the app, simply open the project in Xcode, replace OPENAI_API_KEY in ContentView.swift with your key, set your iOS signing team, and build and run on your iPhone. The audio chat with OpenAI Realtime API can't run on iOS simulator.
MIT