Introduction

Adding payments to a project usually takes a ton of work: Stripe or Polar integration, checkout and webhook plumbing, user handling, billing UI. neonFin handles all of that for you - a payment microservice shared by every project you build.

Set up payments, products, credits, and webhooks once, then plug each new project into the same system. neonFin doesn't replace Stripe or Polar; it sits on top of them and handles the surrounding work.

It is for the tools that are useful enough to charge for, but too small to deserve a week of billing infrastructure.

Why not just use Stripe or Polar directly?

Stripe and Polar are excellent payment providers. neonFin does not replace them. It gives your side projects the layer that usually sits around them:

• Product and price management for each project.
• Checkout creation.
• Webhook verification and fulfillment.
• Credit wallets and usage deductions.
• Anonymous recovery codes for projects without login.
• A small admin dashboard for orders, wallets, products, and webhook events.
• Drop-in shadcn components for balances, purchase buttons, and credit gates.

For a small project, that surrounding work can be larger than the project. With neonFin, Stripe or Polar still handle money, invoices, taxes, and payment methods. Your app talks to one small neonFin integration.

A typical side project

Imagine a tool that processes uploaded videos. You want:

• 2 processing hours free every month.
• A "Buy 10 more hours" option.
• No forced account system - you don't want to set up some huge auth integration just for this tool.
• A visible balance and a way to restore credits later.

With neonFin:

1. The visitor opens the tool.
2. neonFin creates a credit wallet and stores a code like SKIP-8F3K-L9PQ-2MVT.
3. Your code simply deducts minutes when a file is processed using the neonFin SDK.
4. No custom components needed - the balance display, purchase button, and credit gate are all provided.
5. If the user needs more, Stripe Checkout or Polar collects payment.
6. neonFin receives the webhook and adds credits to the same wallet.

If the project already has authentication, use external auth instead of credit codes and attach wallets to your own user ids.

Start here

• Getting started follows the easiest path: Stripe, credit codes, one product, one gated feature.
• Common workflows shows how to handle subscriptions, billing portals, refunds, and support adjustments.
• Components & utils documents every shadcn registry item.
• Client & API covers custom UI and server-side integrations.
• Self-host explains deployment, providers, database, and registry URLs.

The fastest path is the getting started guide.