Every agent session on this machine exports telemetry, so I can see what my own automation costs. The built in token counters turned out to undercount badly: concurrent sessions all wrote into one metric identity, and the collector dropped or reset samples that did not line up. I wrote a single writer exporter instead. It reads the session files on disk, publishes a counter that only goes up, and persists its byte offsets so the number survives a restart or a rotated file. A rule fires when the weekly budget crosses 80 percent, averaged over fifteen minutes so parallel sessions reporting stale integers do not flap it. Nothing pages me. It shows up on the dashboard I already look at, which is enough.