Integrate Extensiv 3PL Warehouse Manager REST API for inbound and outbound order processing

Steps

1. Request REST API access by emailing api@extensiv.com and completing the API Integration Survey; once provisioned, obtain your Customer ID, Client ID, and Client Secret from the Extensiv admin.
2. Exchange credentials for an access token: Base64-encode the string ClientID:ClientSecret and POST it to the token endpoint; include the token in the Authorization: Bearer header on subsequent calls.
3. Refresh the access token every 50–55 minutes before expiry; the token is valid for approximately one hour and expired tokens produce silent 401 errors.
4. Create an outbound order by POSTing to the orders endpoint with the customer ID, ship-to address, carrier/service, and line items (SKU, quantity, unit of measure); Extensiv returns an order ID.
5. Query inventory levels via the inventory endpoint filtered by customer ID and SKU to reconcile stock positions between your commerce platform and the 3PL warehouse.
6. Subscribe to order status webhooks or poll the order endpoint to detect when orders are picked, packed, shipped, and when a tracking number is assigned; propagate tracking to your customer-facing channels.