Getting Started

This guide walks you through creating your first checkout session using Gale’s API. By the end, you’ll understand the full payment flow.

Base URL

https://api.withgale.com/api/v2

Use test API keys (prefix glm_test_) during development. All test transactions are processed in sandbox mode with no real charges.

Authentication

Include your API key in the Authorization header:

Authorization: Bearer glm_test_YOUR_API_KEY

Generate an API key in the Gale Dashboard under Developer Tools > API Keys. The full key is shown only once, when you generate it — copy it straight away. See Authentication for details.

Quick Start

1. Sync a Product

Before creating a checkout, sync your product catalog so Gale can determine HSA/FSA eligibility.

curl -X POST https://api.withgale.com/api/v2/products \
  -H "Authorization: Bearer glm_test_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Digital Blood Pressure Monitor",
    "merchant_product_id": "BP-MONITOR-001",
    "upc_code_or_gtin": "14567890123456",
    "price": 4995,
    "currency": "USD"
  }'

The response includes eligibility status:

{
  "success": true,
  "data": {
    "id": 12345,
    "name": "Digital Blood Pressure Monitor",
    "merchant_product_id": "BP-MONITOR-001",
    "price": 4995,
    "eligibility": {
      "hsa_fsa_eligible": true,
      "message": "SIGIS verified - Medical device"
    }
  }
}

2. Create a Checkout Session

Create a checkout session and get a URL to redirect your customer to:

curl -X POST https://api.withgale.com/api/v2/checkout \
  -H "Authorization: Bearer glm_test_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "reference_id": "your-order-123",
    "customer": {
      "email": "jane@example.com",
      "first_name": "Jane",
      "last_name": "Doe"
    },
    "line_items": [
      {
        "product_id": "BP-MONITOR-001",
        "name": "Digital Blood Pressure Monitor",
        "price": 4995,
        "quantity": 1
      }
    ],
    "shipping_info": {
      "address_line_1": "123 Main St",
      "city": "New York",
      "state": "NY",
      "postal_code": "10001",
      "country": "US"
    },
    "shipping": 500,
    "tax": 410,
    "success_url": "https://yoursite.com/order/success",
    "failure_url": "https://yoursite.com/order/failed"
  }'

Response:

{
  "success": true,
  "checkout_id": "01HXYZ...",
  "checkout_url": "https://checkout.withgale.com/checkout/01HXYZ...",
  "status": "open",
  "expires_at": "2026-02-26T14:30:00Z"
}

3. Redirect Customer

Send your customer to the checkout_url. Gale’s hosted checkout page handles:

HSA/FSA card collection
Eligibility verification
Letter of Medical Necessity (LMN) flow for dual-purpose items
Payment processing

After payment, the customer is redirected to your success_url or failure_url.

4. Confirm Payment

Option A: Webhooks (recommended) Register a webhook endpoint in your Dashboard under Settings > Webhooks. Gale sends an order.created event when payment succeeds:

{
  "type": "order.created",
  "data": {
    "id": "ord_abc123",
    "status": "completed",
    "checkout_id": "01HXYZ...",
    "reference_id": "your-order-123",
    "customer": {
      "email": "jane@example.com"
    }
  }
}

Option B: Poll for status Check the checkout status by querying the order:

curl https://api.withgale.com/api/v2/orders/{order_id} \
  -H "Authorization: Bearer glm_test_YOUR_API_KEY"

Three Key IDs

ID	What it is	When you get it
`checkout_id`	The checkout session you created	Returned when you create a checkout
`order_id`	The payment record after successful payment	Returned in webhooks and order queries
`reference_id`	Your own order/cart ID for correlation	You provide this when creating a checkout

Testing

Use test API keys (glm_test_*) during development. Test card numbers:

Card Number	Result
`4111 1111 1111 1111`	Successful payment
`4000 0000 0000 0002`	Card declined

See Test Cards for the full list.

Next Steps

Integration Flow

Full end-to-end integration walkthrough

Checkout Guide

Detailed checkout integration guide

API Reference

Complete API endpoint documentation

Webhooks

Set up real-time event notifications

Getting Started

Integration Guides

Core Objects

Checkout

Payment Links

Orders

Products

Subscriptions

Webhooks & Errors

Getting Started

Getting Started

Base URL

Authentication

Quick Start

1. Sync a Product

2. Create a Checkout Session

3. Redirect Customer

4. Confirm Payment

Three Key IDs

Testing

Next Steps

Integration Flow

Checkout Guide

API Reference

Webhooks

​Getting Started

​Base URL

​Authentication

​Quick Start

​1. Sync a Product

​2. Create a Checkout Session

​3. Redirect Customer

​4. Confirm Payment

​Three Key IDs

​Testing

​Next Steps

Integration Flow

Checkout Guide

API Reference

Webhooks

Getting Started

Base URL

Authentication

Quick Start

1. Sync a Product

2. Create a Checkout Session

3. Redirect Customer

4. Confirm Payment

Three Key IDs

Testing

Next Steps