Custom Integration Guide

Use this guide when your platform has no pre-built WeGetFinancing plugin, or when you need full control over the checkout experience. The same v1 API underpins all platform plugins — this guide documents it directly.

How It Works

The WeGetFinancing checkout flow has three phases:

Your server calls the API to create a financing request and receives a href URL.
The customer completes the financing application at that URL (shown in a lightbox or redirect).
WeGetFinancing posts a server-side postback to your configured URL when a lender decision is made.

Cart → POST /merchant/{id}/requests → { href, request_token }
                                            ↓
                             Customer opens href (lightbox / redirect)
                                            ↓
                         WeGetFinancing POSTs approved/rejected to your server
                                            ↓
                                     Create or cancel order

Step 1 — Create a Financing Request

POST https://api.wegetfinancing.com/merchant/{merchant_id}/requests

See Create Request for the full field reference and multi-language examples.

Minimal example:

curl -X POST \
  -u "username:password" \
  -H "Content-Type: application/json" \
  "https://api.sandbox.wegetfinancing.com/merchant/YOUR_MERCHANT_ID/requests" \
  -d '{
    "merchant_transaction_id": "ORDER-123",
    "first_name": "Jane",
    "last_name": "Doe",
    "email": "jane@example.com",
    "phone": "2125551234",
    "billing_address1": "123 Main St",
    "billing_city": "New York",
    "billing_state": "NY",
    "billing_zipcode": "10001",
    "shipping_address1": "123 Main St",
    "shipping_city": "New York",
    "shipping_state": "NY",
    "shipping_zipcode": "10001",
    "amount": "499.00",
    "version": "1.9",
    "cart_items": [
      {
        "sku":        "WID-001",
        "display_name": "Super Widget",
        "unit_price":   "499.00",
        "quantity":     "1",
        "unit_tax":     "0.00"
      }
    ]
  }'

Successful response:

{
  "href": "https://app.wegetfinancing.com/checkout?token=abc123",
  "request_token": "abc123def456"
}

Use merchant_transaction_id to correlate the returned postback with your order. Use version: "1.9" to receive JSON-formatted postbacks.

Step 2 — Present the Flow to the Customer

The lightbox opens the financing flow in an overlay on top of your checkout page — no redirect required.

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script src="https://cdn.wegetfinancing.com/libs/1.0/wegetfinancing.js"></script>
<script>
  // After receiving href from your server:
  var onComplete = function() {
    // Fires when the customer completes the flow in the browser.
    // NOTE: do NOT create the order here — wait for the server-side postback.
  };
  var onAbort = function() {
    // Customer closed the lightbox without completing.
  };
  new WeGetFinancing("HREF_FROM_API", onComplete, onAbort);
</script>

See Lightbox Widget for the full API.

Option B — Direct Redirect

Simply redirect the customer to the href returned by the API. After completion, WeGetFinancing redirects back to the URL you configured in the partner portal under Integration → Postback Settings → Return URL.

Option C — Link Integration

Pre-generate a financing URL without collecting customer details upfront. The customer fills in their information on the WeGetFinancing side.

See Link Integration for setup.

Step 3 — Handle the Postback

WeGetFinancing POSTs a JSON payload to your configured postback URL when a lender makes a decision. This is the authoritative signal — always create or cancel orders based on the postback, not browser callbacks.

Postback URL configured at: Partner Portal → Integration → Postback Settings

Postback Payload (v1.9 JSON)

{
  "request_token":          "abc123def456",
  "merchant_transaction_id": "ORDER-123",
  "status":                 "approved",
  "approved_amount":        "499.00",
  "version":                "1.9"
}

`status`	Meaning
`approved`	Lender approved — create the order
`preapproved`	Customer pre-qualified but hasn’t accepted an offer yet — no order yet
`rejected`	All lenders declined — no order
`cancelled`	Customer or lender cancelled — no order

Verify the postback signature before acting on it. See Postbacks to Merchants for the x-signature verification algorithm.

Respond with HTTP 2xx immediately. Do not perform slow operations synchronously — WeGetFinancing will retry on non-2xx responses.

Order Management Pattern

Never create an order on the browser onComplete callback — it can be spoofed. Use the server-side postback as the single source of truth.

-- 1. Before calling the API, save the cart in a pending table
INSERT INTO wgf_pending_carts (merchant_transaction_id, cart_data, created_at)
VALUES ('ORDER-123', '...', NOW());

-- 2. On approved postback, promote pending cart → order (idempotent check first)
INSERT INTO orders
  SELECT * FROM wgf_pending_carts WHERE merchant_transaction_id = 'ORDER-123'
  AND NOT EXISTS (SELECT 1 FROM orders WHERE wgf_token = 'abc123def456');

DELETE FROM wgf_pending_carts WHERE merchant_transaction_id = 'ORDER-123';

Sandbox Testing

Credentials

Get sandbox credentials from the partner portal under Integration → API Integration:

Environment	API Base URL
Sandbox	`https://api.sandbox.wegetfinancing.com`
Production	`https://api.wegetfinancing.com`

The sandbox is fully isolated from production — no real lenders, no real charges.

Forcing Postback Decisions

Postbacks only fire when a lender reaches a decision. To trigger one quickly:

Submit an amount outside your configured lending range (e.g., $1) — lender rejects immediately.
Complete a test application using the mock credentials in the portal under Integration Instructions.

Verifying Delivery

Portal → Integration → Sent Postbacks — shows each delivery attempt with URL, HTTP status, timestamp, and full payload.

Security Checklist

Item	Detail
Verify `x-signature`	Always verify the postback signature using `dhd_username` / `dhd_password`. See Postbacks.
HTTPS on postback URL	WeGetFinancing POSTs to whatever URL you configure — use TLS.
Idempotent order creation	Guard against duplicate postbacks — check `request_token` before inserting.
Ignore `onComplete` for order creation	The browser callback can be manipulated.
Use `merchant_transaction_id`	Tie each request to your own order ID for easy postback correlation.
Use `version: "1.9"`	Ensures JSON postback format — easier to parse and sign than the legacy URL-encoded format.
Respond 2xx quickly	Avoid slow synchronous processing in your postback handler.

Pre-Launch Checklist

approved postback received → order created
Customer closes lightbox without completing → onAbort fires → no order created, no postback
preapproved postback → no order created
rejected postback → customer informed gracefully, no order
Duplicate postback ignored (no duplicate order)
x-signature verified correctly on every postback
Postback handler returns HTTP 200 within 5 seconds
Tested on mobile (both lightbox and redirect flows)