Add docs/authorize-net.md

docs/authorize-net.md

@@ -0,0 +1,56 @@
+# Authorize.net Setup
+
+Authorize.net is the payment processor used by the NotShop bundle. Unlike Shopify Payments, you own the merchant account with no platform lock-in.
+
+**Rate:** 2.9% + $0.30 per transaction. No monthly fee on the pay-as-you-go plan.
+
+---
+
+## Step 1: Create an account
+
+Go to [authorize.net](https://www.authorize.net) → sign up → **Payment Gateway**.
+Approval takes 1–2 business days. Requires a business bank account and EIN/SSN.
+
+**For testing:** Free sandbox at [developer.authorize.net](https://developer.authorize.net).
+
+---
+
+## Step 2: Get API credentials
+
+1. Merchant Interface → **Account → Settings → Security Settings → API Credentials and Keys**
+2. Copy your **API Login ID**
+3. Generate a **Transaction Key**
+
+Add to `.env`:
+
+```
+AUTHNET_API_LOGIN_ID=your_login_id
+AUTHNET_TRANSACTION_KEY=your_transaction_key
+AUTHNET_ENV=sandbox   # change to "production" when ready
+```
+
+---
+
+## Step 3: Test
+
+Authorize.net test card numbers:
+
+| Card | Number |
+|---|---|
+| Visa (approve) | 4111111111111111 |
+| Mastercard (approve) | 5424000000000015 |
+| Decline | 4000000000000002 |
+
+CVV: any 3 digits. Exp: any future date.
+
+---
+
+## Step 4: Go live
+
+Change `AUTHNET_ENV=production`, redeploy, then run a real $1.00 test transaction and void it immediately.
+
+---
+
+## Why Authorize.net
+
+Shopify's transaction fee coercion (0.5%–2% of GMV on non-Shopify Payments processors) effectively penalizes any competing processor. Authorize.net was NaturoMedica's processor before Shopify and is restored here as the sovereign default. To use Stripe instead, see `server/payments.ts` and replace the Authorize.net SDK calls with Stripe's equivalent.