Where the workflow shifted
Stripe's usage-based billing guide for AI highlights the usage event contract, where product actions move through metering, aggregation, and invoices.
AI products should separate completions, embeddings, agent steps, API calls, generated results, and human review before a monthly invoice has to explain them.
Tool names are not outcomes
The signal matters when it changes how a team ships, reviews, or recovers work, not when it only names another tool.
Check permissions and failure
- Define event name, trigger, billable unit, dedupe rule, delay, and user-visible explanation for every metered action
- Keep the test narrow: one low-risk task or tool entry before connecting permissions, logs, failure handling, and human takeover to production
What still needs proof
Unstable event definitions distort cost, allowance, invoices, refunds, and support work. Keep the original source open so the announcement, the evidence, and this site's interpretation stay separate.