2.2k stars · Apache-2.0 · v1.0.0-beta.232 (2026-08-04) · Track this in Scout
Real-time usage metering with entitlements and balances — built for products whose unit of cost is a model call.
▶Repo detailsthe review · specs · pros & cons
What it is
A real-time usage metering service aimed at AI, API and infrastructure products: it collects usage events, aggregates them continuously, and enforces entitlements and balances. It sits between your application and whatever eventually bills the customer.
What it is good for. When the marginal cost of a product is a model call, the moment you offer a free tier you must answer "has this account used up its allowance?" on every single request — cheaply, without scanning a table. That is what an entitlement is, and it is the piece people hand-roll badly and then discover is wrong at the worst moment. OpenMeter is also the cleanest way to put a live "62 of 100 maps used" bar into the product, which is a retention and upgrade prompt as much as an accounting detail. It overlaps Lago (#1) directly: OpenMeter meters and gates, Lago meters and invoices. Read both and pick one — two counters that disagree is worse than neither.
- Built for token- and request-shaped usage, including entitlements and balances, not just end-of-month invoicing.
- Apache-2.0, so it can live inside a paid feature — unlike Lago's AGPL.
- Active and small: beta.232 on 4 August, with releases most months this year.
- Still
1.0.0-betaafter 232 tags — the project is not yet promising API stability. - The production deployment wants ClickHouse and Kafka; the light footprint is the development one.
- 2.2k stars and a young company behind it. This is a bet on a vendor as much as a dependency.
The remaining balance reads straight into the React header; the totals feed Lago or Polar for the actual charge.
