Best Open-source Subscription Billing & Payments tools

Polar

Turn your software into a revenue stream effortlessly.

Lago

Open-source metering and usage-based billing API for SaaS

Autumn

Plug‑and‑play billing layer for any pricing model

Flexprice

Usage-based metering and billing infrastructure for developers

OpenMeter

Real-time usage metering and billing for AI and DevOps

Kill Bill

Open-source subscription billing and payments platform for SaaS

Hyperswitch

Composable open-source payments infrastructure built in Rust

Lotus

Flexible pricing engine for SaaS, usage‑based and custom plans

Meteroid

Cloud-native pricing and billing infrastructure for product-led SaaS

Formance

Modular developer platform for complex financial transaction flows

Laravel Soulbscription

Subscription and feature consumption management for Laravel applications

BillaBear

Self-hostable subscription billing system integrated with Stripe