Polar

Polar is the financial layer for software that charges by usage. It removes the need to build billing infrastructure from scratch, which for an AI company means metering tokens, agent runs, and compute long before any of it becomes an invoice.

Pricing models compose instead of being fixed. Usage billing, subscriptions, seats, credits, trials, and discounts can be combined however the product charges, and metering is precise down to the individual event.

Polar also acts as merchant of record, which changes how much of the billing operation a team has to run itself.

• Tax handling: sales tax and VAT are handled worldwide on the seller's behalf.
• Billing boilerplate: receipts, customer accounts, and dunning belong to the platform rather than the product.
• Checkout and metrics: hosted checkouts and realtime revenue metrics come with the integration.
• AI workloads: token billing wraps any model call, agent runs are charged with step-level granularity and retries that avoid double billing, and GPU work is metered by the second.
• API and SDKs: an HTTP API with maintained SDKs for JavaScript and Python covers docs, sites, and services.

Fees are charged per transaction, starting at 5.00% plus 50 cents on the free Starter plan and falling across the paid tiers, and eligible startups can apply for a year on the most generous plan. Feature requests and bug reports go through the dashboard, and the repository documents how to set up a development environment.