Polar: Sell SaaS, Downloads & License Keys Without Writing Billing Logic 
One-Line Flow:
Some absolute legends spent $2M and 3 years building a “sell anything digital” engine with taxes, subscriptions, and auto-delivery — then dumped it on GitHub for free. Go grab it.
What the hell is Polar?
Polar turns your side project into a money machine.
You plug it in. It handles payments, receipts, subscriptions, taxes worldwide, and all the finance bullshit you hate. You keep building cool stuff.
Website: polar.sh
GitHub: github.com/polarsource/polar
Docs: docs.polar.sh
Discord: discord.gg/Pnhfz3UThd
Why This Isn’t “Just Another Stripe Wrapper”
Polar is a Merchant of Record.
When someone in Germany buys your thing, Polar is legally the seller. They collect the VAT. They file the paperwork. They deal with the EU bureaucracy nightmare.
You just get paid.
They have EU VAT registration, US state registrations, and use global accounting firms. The $1,700/year cost per market? They pay it, not you.
This alone saves you from the “oh fuck I owe taxes to 47 countries” moment.
Details: docs.polar.sh/merchant-of-record/introduction
What Can You Sell?
- SaaS subscriptions
- One-time digital products
- File downloads (up to 10GB per file)
- License keys (auto-generated and validated)
- Private GitHub repo access (auto-invites collaborators)
- Discord server roles (auto-assigned)
- Bundles and packages
If it lives on the internet and people would pay for it — Polar handles it.
Pricing (No Bullshit)
- 4% + $0.40 per transaction
- $0 monthly fee
Sell something for $20 → Polar takes ~$1.20 → You keep the rest without writing billing code.
Hidden costs: Chargebacks = $15 each. Payouts = $2/month + small percentage. Still cheaper than everyone else.
Full breakdown: polar.sh/resources/pricing
Competition Smackdown
| Platform | Fee | Handles Taxes? |
|---|---|---|
| Polar | 4% + $0.40 |  Globally |
| Stripe | 2.9% + $0.30 + headaches |  You’re alone |
| Lemon Squeezy | 5% + $0.50 | Yes |
| Gumroad | 10% + 2.9% | Yes |
On $25K in sales: Stripe ~$725, Polar ~$1,000, Lemon Squeezy ~$1,250, Gumroad ~$3,225.
Polar is 20% cheaper than other MoR platforms.
Lemon Squeezy warning: Since Stripe bought them (July 2024), users report checkout errors and ghost support. Migration tools exist for a reason.
The Hidden Good Shit
Auto-Delivery System: When someone pays, Polar automatically:
- Generates and validates license keys
- Sends file downloads
- Invites them to Discord with specific roles
- Adds them as GitHub collaborators
- Triggers webhooks to your systems
No 3am “oh shit I forgot to send the download link” moments.
Checkout options: Embedded overlay, custom fields, discount codes, pre-filled customer data, API session creation.
Payouts
Minimums: $20 USD / €20 EUR / £20 GBP
Works in 100+ countries including India, Indonesia, Nigeria, Pakistan, Philippines, Bangladesh, Kenya, Vietnam — places Stripe normally won’t touch directly.
Timing: 4-7 business days. You control when to withdraw.
Details: docs.polar.sh/features/finance/payouts
What You CAN’T Sell
Hard no: Physical goods, consulting/services, adult content, donations, marketplaces, gambling, crypto/NFTs, IPTV, medical advice, “get rich” schemes.
Needs approval: Directories, pre-orders, ebooks, ticket sales.
No PayPal support — notable gap vs Lemon Squeezy.
Full policy: docs.polar.sh/merchant-of-record/acceptable-use
SDKs & Integrations
Official SDKs:
- JavaScript: github.com/polarsource/polar-js
- Python: github.com/polarsource/polar-python
- Go, PHP: In the polarsource GitHub org
Framework adapters: github.com/polarsource/polar-adapters — Next.js, Remix, SvelteKit, Astro, Nuxt, Express, Fastify, Hono, Supabase, Deno.
You don’t hand-roll webhooks unless pain is your kink.
GitHub Integration
GitHub officially added Polar as a funding platform (March 2024).
Add to your FUNDING.yml:
polar: your-username
GitHub Sponsors: 0% fee, but you handle all taxes yourself.
Polar: 4% fee, but taxes handled globally + auto-delivers benefits.
Migration
From Lemon Squeezy:
npx polar-migrate@latest
Moves products, license keys, files, discount codes, customers. Active subscriptions need customers to re-subscribe.
Docs: docs.polar.sh/migrate
Self-Hosting (Reality Check)
Yes, it’s Apache 2.0. Yes, you can self-host.
But: Self-hosting = no Merchant of Record benefits. That’s the whole point.
Needs: PostgreSQL, Redis, S3/Minio, Node.js 22, Python 3, Stripe account, GitHub App. No production docs — only dev setup.
Guide: github.com/polarsource/polar/blob/main/DEVELOPMENT.md
Who’s Using This?
- SerenityOS / Ladybird Browser — Open source issue funding
- Litestar — Python framework at polar.sh/litestar-org
- Nuxt founders are angel investors
Stats: 17,000+ signups, 120%+ MoM revenue growth, $10M seed from Accel, angels include Vercel/Supabase/HashiCorp founders.
Open-Source Alternatives
Lago — github.com/getlago/lago
Usage-based billing. 8,800+ stars. Best for AI/API companies. docker compose up and done.
Kill Bill — github.com/killbill/killbill
Enterprise beast since 2010. 50+ plugins. Needs Java knowledge.
Hyperswitch — github.com/juspay/hyperswitch
39,000+ stars. Payment routing across 50+ processors. Rust-based.
BTCPay Server — github.com/btcpayserver/btcpayserver
Bitcoin/Lightning with zero platform fees. Crypto-native’s dream.
Invoice Ninja — github.com/invoiceninja/invoiceninja
Freelancer invoicing with mobile apps.
Quick Links
| What | Where |
|---|---|
| Website | polar.sh |
| GitHub | github.com/polarsource/polar |
| Docs | docs.polar.sh |
| Pricing | polar.sh/resources/pricing |
| Tax/MoR | docs.polar.sh/merchant-of-record/tax |
| Webhooks | docs.polar.sh/integrate/webhooks/events |
| Discord | discord.gg/Pnhfz3UThd |
| Sandbox | sandbox.polar.sh |
Bottom Line
Use Polar if: You’re selling digital stuff and don’t want to become a tax accountant in 47 countries.
Skip Polar if: You need PayPal, sell physical goods, or do consulting.
The honest take: Three-person team, $10M funded, real users, real growth. The Merchant of Record thing is genuinely valuable — most people underestimate how badly international taxes can fuck you.
Worst case: You learn how a proper payments engine works.
Best case: This is the backbone of the thing that finally pays your bills.
!