Agent Token Usage Meter: How to Measure and Control AI Agent Costs in 2026
An agent token usage meter is the component that reads the provider’s usage object on every model response, keeps input, output, and cache-read tokens separate, and converts those counts into dollars at log time using a versioned price table. It meters a run, not a request, because one agent task fans out into dozens of model calls. That is the short answer. The rest of this guide separates the four quantities people keep collapsing into one number, shows where the ground truth actually lives, explains the OpenTelemetry contract the industry is converging on, and states plainly where the current tooling still fails. ...