Payments

Kill Bill5.4k★

Kill Bill is the open-source billing platform for teams whose subscription logic doesn't fit in Stripe's box. Plugin-driven, Java-based, and battle-tested in telecoms and fintech — it handles the gnarly edge cases like prorations, usage-based billing, multi-currency, and complex plan transitions. If you're building a SaaS with billing needs that Stripe Billing can't express, Kill Bill gives you full control. Lago is the modern, developer-friendly alternative — lighter, REST-first, better docs. OpenMeter handles usage metering specifically. Commercially, Stripe Billing and Chargebee cover 90% of subscription use cases with far less setup. The plugin architecture means you can extend payment gateways, notification systems, and tax calculations without forking the core. The catch: Kill Bill is enterprise-grade complexity. Java, OSGI bundles, and a steep learning curve that'll cost you weeks before you're productive. The documentation assumes enterprise architects, not indie hackers. For most SaaS founders, Stripe Billing plus a webhook handler covers 95% of what you need. Only reach for Kill Bill when Stripe genuinely can't model your pricing — and verify that's actually true before committing.