Important: these are billing layers, not payment processors
None of these moves money by itself. Lago, Flexprice, OpenMeter, Meteroid, UniBee, Paymenter, and Autumn manage plans, usage, and invoices and then charge through processors such as Stripe or PayPal. Hyperswitch routes payments across many processors. Formance provides a ledger and financial workflows, and Crater is a simple invoicing app.
Usage-based billing options
Lago, Flexprice, OpenMeter, Meteroid, and Autumn target usage-based and hybrid pricing for SaaS, AI, and API companies, with real-time metering, credits, and flexible plans. OpenMeter focuses on metering and usage limits, while Lago and Meteroid also handle invoicing end to end.
License details
Hyperswitch, OpenMeter, and Autumn are Apache-2.0, Paymenter is MIT, and Formance's ledger is MIT. Lago, Meteroid, UniBee, and Crater are AGPL-3.0, and Flexprice is AGPL-3.0 with a commercial Enterprise directory. Formance's wider stack keeps an ee directory under an Enterprise license.
Self-hosting and cost
All can be self-hosted, and most also offer managed cloud plans. Autumn can be self-hosted but depends on several services, so the team points to its hosted version for most users. Paymenter offers cloud deployment from $5 per month, and Autumn's hosted plan is free until a revenue threshold.
Maintenance status
Crater has had no commits since August 2024, and UniBee's last commit was in February 2026. Hyperswitch, Lago, Flexprice, Autumn, Paymenter, OpenMeter, Meteroid, and Formance were updated within days or weeks of this update.