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Documentation Index

Fetch the complete documentation index at: https://docs.withgale.com/llms.txt

Use this file to discover all available pages before exploring further.

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Checkout Integration

The most common way to integrate Gale. Create a checkout session via API, redirect your customer to Gale’s hosted page, and we handle the rest—including card collection, eligibility detection, and LMN flow for dual-purpose products.

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How It Works

  1. Customer clicks “Checkout” on your site
  2. Your site creates a checkout session via POST /v2/checkout
  3. Gale returns a checkout_url
  4. Your site redirects customer to the checkout URL
  5. Customer completes payment on Gale’s hosted page
  6. Gale sends webhook with order.created event
  7. Your system fulfills the order
  8. Customer is redirected back to your success_url

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When to Use Checkout

Using Shopify or WooCommerce? Install our plugin instead:The Checkout API is for custom platforms and sites not supported by our plugins.
Perfect for:
  • Custom e-commerce platforms
  • Membership and subscription platforms
  • SaaS applications
  • Next.js, React, or custom-built sites
  • Adding HSA/FSA payments alongside existing payment methods
Use cases:
  • Next.js membership site with monthly subscriptions
  • Custom healthcare e-commerce store
  • Wellness platform built on custom stack
  • Telehealth service with custom checkout

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Quick Start

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1. Create Checkout Session

const createCheckout = async (cart) => {
  const response = await fetch('https://api.withgale.com/v2/checkout', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${process.env.GALE_API_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      reference_id: cart.id,
      customer: {
        email: cart.customerEmail,
        first_name: cart.firstName,
        last_name: cart.lastName
      },
      line_items: cart.items.map(item => ({
        product_id: item.sku,
        name: item.name,
        quantity: item.quantity,
        price: item.price,
        currency: 'USD'
      })),
      shipping_info: cart.shippingAddress,
      shipping: cart.shipping,
      tax: cart.tax,
      success_url: 'https://yoursite.com/order/success',
      failure_url: 'https://yoursite.com/cart'
    })
  });

  const checkout = await response.json();
  return checkout.checkout_url;
};

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2. Redirect Customer

// Redirect to Gale's hosted checkout
const checkoutUrl = await createCheckout(cart);
window.location.href = checkoutUrl;

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3. Handle Webhook

app.post('/webhooks/gale', async (req, res) => {
  const event = req.body;

  if (event.type === 'order.created') {
    const order = event.data;

    // Fulfill the order
    await fulfillOrder(order.id, {
      items: order.line_items,
      shipping: order.customer.shipping_address
    });

    // Send confirmation email
    await sendEmail({
      to: order.customer.email,
      subject: `Order ${order.order_number} Confirmed`,
      template: 'order_confirmation'
    });
  }

  res.status(200).send('OK');
});

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Integration Examples

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Next.js Membership Site

// app/checkout/route.ts
import { NextResponse } from 'next/server';

export async function POST(request: Request) {
  const { tier, customerId } = await request.json();

  const membershipPlans = {
    basic: { productId: 'BASIC-001', price: 2900 },
    premium: { productId: 'PREMIUM-001', price: 4900 },
    elite: { productId: 'ELITE-001', price: 9900 }
  };

  const plan = membershipPlans[tier];

  const response = await fetch('https://api.withgale.com/v2/checkout', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${process.env.GALE_API_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      customer: await getCustomer(customerId),
      line_items: [{
        product_id: plan.productId,
        name: `${tier} Membership`,
        quantity: 1,
        price: plan.price,
        currency: 'USD'
      }],
      payment_type: 'subscription',
      subscription: {
        interval: 'monthly'
      },
      success_url: `${process.env.BASE_URL}/welcome?tier=${tier}`,
      failure_url: `${process.env.BASE_URL}/pricing`
    })
  });

  const checkout = await response.json();
  return NextResponse.json({ url: checkout.checkout_url });
}

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React E-commerce Checkout

function CheckoutButton({ cart }) {
  const handleCheckout = async () => {
    const response = await fetch('/api/create-checkout', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ cart })
    });

    const { checkout_url } = await response.json();
    window.location.href = checkout_url;
  };

  return (
    <button onClick={handleCheckout} className="checkout-btn">
      Pay with HSA/FSA
    </button>
  );
}

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Shopify Integration

// Add Gale as payment option
const addGalePaymentMethod = () => {
  // In checkout page
  const galeButton = document.createElement('button');
  galeButton.textContent = 'Pay with HSA/FSA';
  galeButton.onclick = async () => {
    const cart = await fetch('/cart.js').then(r => r.json());

    const checkout = await createGaleCheckout({
      customer: {
        email: cart.customer.email,
        first_name: cart.customer.first_name,
        last_name: cart.customer.last_name
      },
      line_items: cart.items.map(item => ({
        product_id: item.sku,
        name: item.title,
        quantity: item.quantity,
        price: item.price,
        currency: 'USD'
      })),
      success_url: window.location.origin + '/thank-you',
      failure_url: window.location.origin + '/cart'
    });

    window.location.href = checkout.checkout_url;
  };

  document.querySelector('.payment-methods').appendChild(galeButton);
};

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What Gale Handles

When customers reach the hosted checkout page, Gale automatically:
  1. Collects payment information - Secure card entry
  2. Detects HSA/FSA eligibility - Real-time SIGIS verification
  3. Handles dual-purpose items - LMN flow when required
  4. Processes payment - Charges appropriate payment method(s)
  5. Creates order - Sends webhook notification to your system

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Checkout URL Customization

Pre-fill customer information to streamline checkout: 
{
  customer: {
    email: "customer@example.com",
    first_name: "Jane",
    last_name: "Doe",
    phone: "+1-555-123-4567"
  },
  shipping_info: {
    address_line_1: "123 Main St",
    city: "New York",
    state: "NY",
    postal_code: "10001",
    country: "US"
  }
}
Customer only needs to enter payment details.

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Subscription Support

For recurring payments, add subscription parameters: 
{
  payment_type: "subscription",
  subscription: {
    interval: "monthly",
    interval_count: 1,
    trial_period_days: 14
  }
}

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Testing

Use test API keys and test cards: 
// Test card numbers
const testCards = {
  success: '4111111111111111',
  decline: '4000000000000002',
  requiresAuth: '4000002500003155'
};
See Test Cards for full list.

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Support

Questions about checkout integration?