Tag
Billing tools
7 reviewed tools: 6 free or open source, 1 paid or paid-led.
Order: free and open source first, then hosted products with a real free tier, then paid-led; catalog order inside each group, with quiet or archived repos last. Not a score, and no tool pays for its place.
7 tools
- PolarApache-2.0 merchant-of-record billing for indie and AI products
Free / OSS · Freemium · 10.4k GitHub stars
VerdictApache-2.0 MoR for indie and AI products. Free Starter, honest take-rate, real SDKs.
CatchNo first-party CLI in the docs index — SDKs, MCP, and API only. Starter take-rate sits on top of card-brand costs. Polar is MoR, so you do not keep the Stripe account relationship. International cards add extra. Payouts have their own cut.
- Kill BillApache-2.0 in-house subscriptions and payments, no % take-rate
Free / OSS · Apache-2.0 · 5.8k GitHub stars
VerdictApache-2.0 billing you run. Free until Aviate or the AMI; never a take-rate.
CatchJVM and ops-heavy. Aviate is the proprietary accelerator — not the Apache tree. Self-Hosted OSS Free; AWS Marketplace is ~$40/mo plus the AWS bill. No revenue tiles here because there is no % of revenue to quote.
- PaymenterMIT hosting billing; self-host free, cloud PaaS $5/mo paid
Free / OSS · Freemium · 2.8k GitHub stars
VerdictMIT hosting billing. Self-host free; cloud PaaS is $5/mo paid.
CatchVs Kill Bill/Lago/Polar: hosting webshop + provisioning (Pterodactyl/cPanel, WHMCS importer) — not generic subscription metering or Polar MoR. Cloud is $5/mo paid. Self-host is the $0 path.
- AutumnApache-2.0 Stripe billing layer; Free to 8K billing volume
Free / OSS · Freemium · 2.8k GitHub stars
VerdictApache-2.0 Stripe billing layer. Free tier real; still bring Stripe.
CatchVs Polar/Lago/OpenMeter: Stripe abstraction + entitlements — not Polar MoR, not Lago/OpenMeter metering-first. Stripe fees still apply. Pro Cloud from $375/mo. Free path is Free tier or self-host.
- Paddle CLIMIT community CLI for full Paddle Billing API; agent-native
Free / OSS · OSS/MIT · 1 GitHub stars
VerdictMIT Paddle Billing CLI. Free tool; Paddle merchant + MoR fees separate.
CatchCommunity CLI — not an official Paddle Inc product; API drift risk. Still need a Paddle merchant account (MoR fees apply). Vs Stripe CLI: Paddle-only. Thin MCP forks exist; this is the general CLI.
- Invoice NinjaELv2 source-available invoicing; self-host free, hosted Free 5 clients
Free / OSS · Open-Core · 10.3k GitHub stars
VerdictELv2 invoicing. Self-host free for your biz; hosted Free 5 clients / Pro paid.
CatchNOT OSI open source — ELv2 forbids offering it as competing hosted SaaS. Hosted Pro from ~$14/mo (2026 pricing). Vs Lago/Autumn: client invoicing, not usage metering/MoR. Attribution stays unless white-label.
- KindeHosted auth plus billing, $0 forever, 10,500 MAU, no OSS
Paid-led · Freemium
VerdictHosted auth+billing with a real $0 forever plan. No repo to fork; branding until Pro.
CatchNot self-host. Kinde branding stays on Free. SMS is 10 included. Pro is $25/mo to uncap MAU and drop branding. Distinct from Polar (Apache MoR, not an IdP) and Clerk (auth UI, no 0.7% billing take-rate on Free).
FAQ
- What is the top free pick among Billing tools?
- Polar leads the Stack Gems list for Billing tools. Verdict: Apache-2.0 MoR for indie and AI products. Free Starter, honest take-rate, real SDKs.
- How many Billing tools does Stack Gems review?
- 7: 6 free or open source, 1 paid or paid-led. Each review has a verdict and an honest Catch; no tool pays for its spot.
- Which Billing tools can I self-host for free?
- Kill Bill, Paymenter, Autumn, Paddle CLI and Invoice Ninja.
- Which Billing tools have the most GitHub stars?
- Polar (10.4k), Invoice Ninja (10.3k), Kill Bill (5.8k), per GitHub on 2026-10-21. Stars measure attention, not fit; read the Catch.
- What is the catch with Polar?
- No first-party CLI in the docs index — SDKs, MCP, and API only.