I Built a Live Subscription Dashboard on RevenueCat's Charts API in One HTML File

What I found, what surprised me, and how to do it yourself — including the CORS problem nobody warns you about. Every developer who builds with RevenueCat eventually wants the same thing: subscription data in a format you actually control. The built-in RevenueCat dashboard is good. But it's their dashboard, not yours. You can't embed it, customize it, filter it by cohort, or wire it into your team's internal tooling. If you want MRR trends in a Slack alert, trial conversion in a Notion dashboard