Polar

Polar is a payments platform aimed at developers and open-source maintainers. Like other merchant-of-record services, it takes on sales tax and VAT obligations, but the product is shaped around the way developer projects sell: sponsorships, paid tiers for repositories, licence keys, and usage-based billing for API products. The integration is API-first with SDKs and a checkout that can be embedded, and there is a first-class GitHub integration for funding models where a sponsorship unlocks repository access or a private issue tracker. Usage-based billing supports metered events, which fits API products that charge by request. It is a younger platform than the established merchant-of-record services, so the ecosystem of integrations and the track record are shorter. Teams that want the developer-oriented billing model and are comfortable adopting an earlier-stage vendor are the natural fit; teams that need a long operating history usually choose a more established platform.