I built a zero-infrastructure audit logging SDK for TypeScript -> here's what I learned

Every B2B SaaS eventually gets this message from a customer: "Someone changed this record — who did it?" If you don't have audit logs, you have no answer. I've seen this problem in fintech systems I've built, and every time the solution was the same: spend two weeks writing the same boilerplate from scratch. So I built trailkit — a lightweight, zero-infrastructure audit logging SDK for TypeScript. Here's what I learned along the way. The problem with existing solutions When I lo