Disclaimer: this is a personal, local-only experiment, not a tested production finding and not a claim about any specific AI vendor or product. Everything here runs on my own machine against a small server I wrote myself. Think of it as a rough idea I worked through with some spare time and a token budget, worth discussing, not a verdict on anything in production.
Picture the order screen above the counter at a busy coffee shop. Your name lights up the instant the barista starts on your order, "Sam, in progress." But the register only logs the sale once the receipt printer finishes, and if that printer jams right after your drink is handed over, you're standing there with a finished coffee while the books say nothing was ever sold.
I found the same gap in AI chat streaming, so I built a small lab to check it. An AI client can render a complete, convincing response to the user while its own billing pipeline records absolutely nothing. No crash. Sometimes not even an error message.
TL;DR: in a streaming AI client where one part renders text and a separate part records billing, a dropped or corrupted frame between the last chunk of text and the usage frame can leave the user with a full response while billing logs zero. No crash, no exception in some cases. Proof of concept, three trigger conditions, and a fix, all local and reproducible: github.com/glatinone/streamblind-poc
