How I built a real-money 1v1 SDK for web games

What Challenge does Devs drop a single <script> tag into their web game. Players match for $2 or $5, winner takes the pot, dev keeps 4.5% of every match. The button lives inside the host game — no separate app to download. <script src="https://api.withchallenge.com/widget/dist/challenge-widget.js"></script>...