Open-source Stripe Billing alternatives

Lago is an open-source billing and monetization platform that meters product usage and turns it into pricing, credits, entitlements, invoices, payments and revenue. It is positioned as infrastructure for AI products, where tokens, compute and API calls need to be measured and charged, but it also handles classic subscriptions and hybrid pricing.

It offers consumption tracking, subscription management, pricing iterations, payment orchestration and revenue analytics. Companies can use Lago Direct to bill their own customers or Lago Embedded to power monetization for their own customers. Integration is through a REST API and SDKs, a CLI for inspecting billing data and running diagnostics, and an MCP server that gives assistants tools to work with live billing data. A local demo prices sample AI requests.

The stack includes Go, Ruby, React and ClickHouse. Lago is licensed under AGPL-3.0 and can be self-hosted, and a managed Lago Cloud is available through the vendor. It suits SaaS and AI companies that want to own their billing logic rather than rely on a closed billing vendor.

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.

Flexprice is monetization infrastructure for AI-native and SaaS teams that charge by usage, credits or a mix of models. It handles metering, pricing, credits and billing so developers do not need to build custom billing logic for every pricing change.

Applications send usage data to Flexprice from backend APIs, AI agents or custom workflows, or stream it from data warehouses and analytics pipelines. Flexprice processes the data in real time, prices usage according to the customer's plan, deducts prepaid or promotional credits, applies feature limits and produces invoices. It then connects to existing payment, CPQ, CRM and accounting tools, such as Stripe, to push invoices and revenue data onward. A no-code interface is included.

The project is written in Go, uses ClickHouse, Kafka, PostgreSQL and Temporal according to its repository topics, and is licensed under AGPL-3.0. It can be used as a cloud service or self-hosted, and documentation, a demo and a Slack community are linked from the README.

OpenMeter is open-source monetization infrastructure for AI, API, and other usage-based products. It collects and aggregates high-volume usage events in real time, enforces access based on usage, and handles usage-based billing from pricing and subscriptions to credits and invoices. It is written in Go, uses ClickHouse and Kafka, and is released under the Apache-2.0 license.

The design is API-first and composable: it can own the entire path from raw usage to invoice, or only the pieces your stack lacks, and it works with payment and tax providers you already use, such as Stripe. The README describes it as best suited to products with usage-based or hybrid pricing, prepaid credits, or usage limits.

Documentation includes a quickstart and an API reference. OpenMeter suits product, finance, and platform engineers who need accurate metering and billing without building it from scratch, and who want to keep the billing stack under their control. A managed cloud version is offered by the project.

Meteroid is a cloud-native pricing and billing platform aimed at SaaS, infrastructure and AI companies. It is designed for businesses moving to usage-based or product-led pricing, closing the gap between what customers use and what they are billed by connecting to your systems through an API.

Its capabilities include usage metering that turns raw events such as API requests, tokens or storage into billable metrics in real time, flexible pricing with flat, usage-based, tiered or hybrid models and versioned plans, and subscription management with upgrades, downgrades and mid-cycle changes. It also covers quotes (CPQ), invoicing, cost limits, grandfathering, experiments and revenue analytics. Topics mention Stripe, ClickHouse and payments.

Meteroid is built with Rust and TypeScript and licensed under AGPL-3.0, and it can be self-hosted. The README also offers a free workspace on Meteroid Cloud with no credit card required, so teams can try it without setup. The latest release is a 1.0 release candidate. It suits product and engineering teams that want ownership of their billing logic.