Polar
Billing platform for software and AI products that handles usage-based pricing, subscriptions, checkouts and tax as merchant of record.
- GitHub stars
- 10k
- Last commit
- today
- Latest release
- @polar-sh/tanstack-start@1.0.1
- Licence
- Apache-2.0
- Hosted version
- Available
Polar is an open-source billing platform aimed at AI startups and other software businesses that need to charge for tokens, agents and compute without building billing infrastructure themselves. It positions itself as the financial layer for intelligent software and acts as the merchant of record.
It supports many pricing models, including usage billing, subscriptions, seats, credits, trials and discounts, which can be combined. Metering can track tokens, API calls, agent runs, GPU seconds and storage at the level of individual events. Checkouts, real-time metrics and worldwide tax handling are included, and as merchant of record Polar takes on receipts, customer accounts, dunning, sales tax and VAT.
Polar is built with Python and FastAPI on the backend and Next.js, React and TypeScript on the frontend, in a Turborepo monorepo, and is licensed under Apache-2.0. An API and SDKs let you integrate it into docs, sites and services. Pricing is per transaction, and an application-based Startup Program is available for eligible startups.
Key features
- Usage-based billing and metering
- Subscriptions, seats, credits and trials
- Checkout flows with real-time metrics
- Merchant of record with tax handling
- Python and TypeScript SDK integrations
Pricing: Free Starter plan charges 5% + 50¢ per transaction. Pro ($20), Growth ($100) and Scale ($400) are monthly fees that lower the per-transaction rate.
