Overview: Polar is an open-source monetization platform designed for developers who want to turn their software into a sustainable business without managing the complexities of payments, tax compliance, or customer billing. It acts as a merchant of record, handling everything from subscription management and receipt generation to VAT and sales tax calculations. Built as a monorepo with a Python/FastAPI backend and a Next.js/TypeScript frontend, Polar provides APIs and SDKs to integrate digital product sales directly into your GitHub repositories, Discord servers, documentation sites, or custom applications. This tool is ideal for indie hackers, open-source maintainers, and SaaS founders who need a plug-and-play solution to start earning from their work without building payment infrastructure from scratch.
What You Get
- Digital Products & Subscriptions - Sell access to GitHub repositories, Discord channels, file downloads, and license keys with built-in subscription management and automated renewals.
- Merchant of Record Services - Handle sales tax, VAT, receipts, and customer accounts automatically—Polar takes legal and financial responsibility for transactions.
- API & SDK Integration - Integrate monetization into your app using the Public API, Webhook API, or official SDKs for JavaScript (Node.js/browsers) and Python.
- No Monthly Fees - Pay only 4% + 40¢ per transaction with no fixed costs, making it ideal for early-stage projects and low-volume sellers.
- Open Source Infrastructure - Full access to the monorepo including FastAPI backend, Next.js dashboard, and shared React components for custom integrations.
Common Use Cases
- Building a GitHub-powered SaaS tool - A developer creates a Python library and uses Polar to offer premium access via paid subscriptions, automatically granting GitHub repository access upon payment.
- Monetizing open-source documentation - A technical writer publishes docs with interactive examples and uses Polar to charge for premium content, handling tax compliance across 50+ countries automatically.
- Problem → Solution flow: Managing recurring payments for a Discord bot - A developer builds a utility bot and needs to charge users monthly. Polar handles subscription billing, renewal reminders, and tax reporting without writing a single line of payment code.
- Team/workflow scenario: Indie dev launching a multi-product SaaS - A solo founder sells a CLI tool, a web dashboard, and premium support via Discord—all through one Polar integration—using the Python SDK to programmatically grant access based on subscription status.
Under The Hood
Polar is a cross-platform development framework designed to unify web and mobile application building through a modular, extensible architecture. It emphasizes developer experience and seamless integration across platforms using shared components and tools.
Architecture
The system adopts a monorepo structure with clear separation between client applications, shared packages, and core modules. It supports multi-platform development through well-defined architectural boundaries.
- Modular design with distinct client and shared codebases
- Strong emphasis on reusable components and unified state management
- Integration of web and mobile development under a single cohesive framework
Tech Stack
The project is built using TypeScript and React, with a focus on modern frameworks and tooling for cross-platform support.
- Built with TypeScript and React, leveraging Expo for mobile and Next.js for web
- Extensive use of UI libraries like Restyle, state management with TanStack Query, and Sentry for error tracking
- Development workflows powered by TurboRepo, Expo CLI, and Vite with PostCSS and Tailwind
- Testing and linting handled through Jest, Vitest, ESLint, and Prettier
Code Quality
The codebase enforces quality through linting and testing practices, though consistency across modules varies.
- Comprehensive linting and formatting rules in place via ESLint and Prettier
- Testing strategies include both mobile and web-focused test suites with rule validation
- Error handling is implemented using standard try/catch patterns in key modules
- Code style and conventions are enforced through tooling, though some technical debt remains
What Makes It Unique
Polar distinguishes itself through its unified developer experience and modular architecture tailored for multi-platform development.
- Developer-first approach with a focus on extensibility and cross-platform consistency
- Modular architecture that enables seamless integration of web, mobile, and backend components
- Strong emphasis on shared code and component reuse across platforms