# Documentation - **Getting started** - [Overview](/): The checkout without the catalog. OrbCart runs Cart, Quote, Payment and Order for your storefront and AI agents, while your products, prices and stock stay in your systems. - [What makes OrbCart different](/why-orbcart): What OrbCart is, what it is not, and how its approach compares with the other ways to take an order online. - [Quickstart](/getting-started): Run the reference shop on your machine in about ten minutes. Then buy something in five lines of code. - **Understand OrbCart** - [Concepts](/concepts): The mental model of OrbCart. Who owns what, the words of a purchase, and why it is shaped this way. - [How it works](/how-it-works): Follow one purchase from cart.add to the Order in your ERP, and see what OrbCart does when something goes wrong. - [Security](/security): The trust model of OrbCart, what each key and token opens, what is not built yet, and what to check before you go live. - **Build your shop** - [Configuration](/configuration): One defineCommerce call describes your whole shop. Markets, shipping, payments and your systems. - Connect your systems - [Offers](/integrations): The one function OrbCart needs from you. Your systems know the goods; offers tells OrbCart. - [Stock & ERP hand-off](/integrations/inventory): Limit purchases to what you can ship, hold it during checkout, and hand every Order to your ERP. - [Contracts in another system](/integrations/remote-contracts): Let your ERP, a Laravel shop or another Worker answer offers, stock, tax and order handoff, over HTTP or a Service Binding. - [Order events](/integrations/events): Tell your systems what happened to an Order and to the purchase before it, such as a confirmation to send or a payment to book. - [Sending the buyer's emails](/integrations/buyer-emails): Confirm Orders, tell buyers a payment did not go through and follow up on a Cart, from your own mail system and OrbCart's events. - [Tax](/integrations/tax): Pick one tax source per Channel. Use the EU's daily rates, or bring your own amounts. - [Signed-in buyers](/integrations/identity): Use your shop's existing login. OrbCart keeps no accounts; it trusts your ID tokens. - Carts & checkout - [Carts](/commerce): Add goods, change quantities and keep the buyer's place across reloads and devices. - [Quotes & payments](/commerce/quotes): Show the exact total, collect the payment and turn the purchase into an Order. - [The order page](/commerce/order-page): Give every buyer, guests included, their order from any device through a secret link, without an account. - [Shipping](/commerce/shipping): Declare where you ship and what it costs. No code, just rules per country. - [Discounts](/commerce/discounts): Codes, automatic promotions, free shipping and redemption limits. Declared, not coded. - [Extensions](/commerce/extensions): Your own typed fields on a Line or the Cart. An engraving, a gift message, a configurator's choices. - Payments - [Payment providers](/payments): Map each payment method to a provider. Swap a provider by changing one word. - [Express checkout](/payments/express): Apple Pay, Google Pay and PayPal buttons right in the bag. Buy without filling in a form. - [Test payments](/payments/test-payments): Cards, accounts and passwords that work in each provider's sandbox. - Recipes - [Recipes](/recipes): Complete, copyable code for the tasks shops build first, from an add-to-cart button to a test that buys something. - [Add to cart and a mini cart](/recipes/add-to-cart): An add-to-cart button for your product pages and a bag in the header that shows the server's Lines and total. - [A checkout without React](/recipes/checkout-without-react): Your own checkout page in plain TypeScript, with the checkout store of @orbcart/client. Details, the binding total, a card field and every outcome of the order button. - [Prices and stock from your ERP](/recipes/erp-prices-and-stock): Answer OrbCart's offers and inventory contracts from an ERP over HTTP, with one request per call, parsed answers and a reservation that never sells the last unit twice. - [Send paid Orders to your ERP](/recipes/erp-order-handoff): Hand every paid Order to your ERP exactly once, keep OrbCart's Line IDs there, and report shipments back so the buyer's order page shows the tracking. - [Free shipping and a welcome code](/recipes/free-shipping-and-codes): Free standard shipping from €50 without a code, 10 % off with WELCOME10, a code field in the bag, and a test that proves both. - [A gift message, end to end](/recipes/gift-message): Declare a gift message once, let the buyer write it in the bag, and print it on the packing slip. Checked on the server, kept in the Quote and frozen in the Order. - [Test a purchase](/recipes/test-a-purchase): A Vitest test that buys a backpack against your real Worker, pays with a card through a fake Stripe, reads the Order back and proves a double click buys once. - **Go further** - [Extend OrbCart](/extend): Every place your code plugs into OrbCart, from one line of configuration to a package of your own, and what cannot be extended yet. - [AI agents](/agents): Let shopping agents check out in your shop over UCP and follow their orders. The buyer agrees on your checkout, or in their agent's app with AP2. - [Testing](/testing): Test real purchases against your own Worker, in Vitest, without a network. - **Reference** - SDKs & tools - [SDKs & tools](/sdks): Which package for which job, and which key goes where. - [React checkout](/sdks/react): Your Cart in, an Order out. One component for the last step of the purchase. - [Orders & refunds](/sdks/admin): Read Orders, give money back and report shipments from your backend. - [CLI](/sdks/cli): The orbcart command. Local development, keys, tax rates and access to the Explorer. - HTTP API - [HTTP API](/api-reference): Call OrbCart from any language. Keys, headers, the endpoints you call and how retries work. - [Errors](/api-reference/errors): Every error code, what caused it and what to do next. - **Ship it** - [Deployment](/deployment): Deploy a test environment to your Cloudflare account, step by step. - [Project status](/status): What works today, what is being built and what comes next.