> ## Documentation Index
> Fetch the complete documentation index at: https://docs.billingos.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Welcome to BillingOS

> Add billing, subscriptions, and payments to your app in minutes — not months.

## What is BillingOS?

BillingOS is a developer toolkit that lets you add complete billing infrastructure to any web app. You get pre-built React components for pricing pages, checkout, and customer portals — plus a server SDK for backend operations like feature gating and usage tracking.

**You don't need to learn Stripe.** BillingOS handles all the payment complexity behind the scenes. Your customers get a polished billing experience, and you ship faster.

<CardGroup cols={3}>
  <Card title="Quickstart" icon="rocket" href="/quickstart">
    Go from zero to accepting payments in 5 minutes.
  </Card>

  <Card title="React SDK" icon="react" href="/sdk/overview">
    Drop-in components for pricing, checkout, and portals.
  </Card>

  <Card title="Node SDK" icon="server" href="/server-sdk/overview">
    Server-side session tokens, entitlements, and usage tracking.
  </Card>
</CardGroup>

## What you can build

<CardGroup cols={3}>
  <Card title="Pricing page" icon="tags">
    Show plans with a single `<PricingTable />` component. Monthly/yearly toggle built in.
  </Card>

  <Card title="Checkout" icon="credit-card">
    Secure, PCI-compliant checkout modal. No Stripe code needed.
  </Card>

  <Card title="Customer portal" icon="user-gear">
    Self-service portal where customers manage subscriptions, invoices, and payment methods.
  </Card>

  <Card title="Feature gating" icon="lock">
    Control access to features based on subscription plan. Works client-side and server-side.
  </Card>

  <Card title="Usage tracking" icon="chart-bar">
    Track API calls, storage, or any metric. Bill based on usage.
  </Card>

  <Card title="Upgrade nudges" icon="arrow-up">
    Automatically prompt users to upgrade when they approach plan limits.
  </Card>
</CardGroup>

## How it works

<Steps>
  <Step title="Install the SDK">
    Add `@billingos/sdk` to your React app and `@billingos/node` to your server. Two packages, zero Stripe dependencies.
  </Step>

  <Step title="Create a session token endpoint">
    Your server creates a short-lived token that securely identifies your customer to BillingOS. The SDK handles token refresh automatically.
  </Step>

  <Step title="Drop in components">
    Add `<PricingTable />` for plans, `<CheckoutModal />` for payments, and `<CustomerPortal />` for self-service billing management.
  </Step>

  <Step title="You're live">
    Customers can subscribe, upgrade, downgrade, and manage their billing. You focus on your product.
  </Step>
</Steps>