Kill Bill is an enterprise-grade, open-source billing and payment platform designed to provide organizations with full control over their financial infrastructure and data.

The main features of this tool include:

• Comprehensive Subscription Management: It offers unrivaled versatility for managing subscriptions, including complex pricing models, trial periods, addons, and various alignment options.

• Flexible Payment Platform: The system integrates with major gateways like Stripe, PayPal, Adyen, and Braintree. It allows for custom payment routing and supports alternative payment methods and e-currencies.

• Usage-Based Metering & Billing: Kill Bill excels at tracking and billing for real-time usage, such as AI tokens or cloud resources, supporting both prepaid (wallets) and postpaid models.

• Unified Admin Interface (Kaui): It includes a dedicated back-office web UI called Kaui, which allows finance, customer success, and developer teams to manage price books, subscriptions, and payments easily.

• Plugin-Based Extensibility: The platform features a robust open plugin framework, allowing developers to extend the core logic, receive bus events, or build custom integrations with tax engines and CRMs.

• Data Sovereignty & No Vendor Lock-in: Because it is self-hosted and open-source, users own 100% of their billing data and avoid the per-transaction fees or revenue-based pricing typical of SaaS competitors.

• Enterprise Scaling with Aviate: For teams needing faster deployment, the Aviate accelerator provides production-ready cloud infrastructure, monitoring, and fixed pricing to bridge the gap between DIY and enterprise operations.