OpenMeter measures consumption so a product can bill for it: real-time metering of AI token usage and API calls, entitlements, and the flexible pricing models that usage-based products need.
Metering is a genuinely hard engineering problem that companies keep rebuilding badly. Counting events accurately enough to charge for them, at high volume and without dropping records, is the sort of thing that looks simple until the first billing dispute arrives.
It is open source, now under Kong, and can be self-hosted. Pricing tiers for the hosted service render client-side, self-hosting is operational work you own, and billing infrastructure is a component you cannot afford to get wrong once customers are on it.
