Whistl Developer Guide & API Credentials

This developer guide shows how to access Whistl shipping API via AfterShip Shipping, and Whistl web service. See also the list of required API credentials / keys for Whistl integration.

Get Whistl Developer Credentials

1. Email Whistl sales representative and cc support+shipping@aftership.com Tell Whistl you need to obtain Whistl web service API credentials.  
2. Whistl will provide testing credentials for Sandbox environment:   Client Code,  Site Code and Customer Number
3. Use the Whistl testing credential to generate a label via AfterShip Shipping Sandbox environment. Send Whistl the sample label, together with request and response xml files.
4. Whistl will provide the production credentials for Whistl web services API:  Client Code,  Site Code and Customer Number

Required Whistl API credentials

Whistl Developer Resources

• Read Whistl docs
• Supported Whistl service types and service options
• AfterShip Shipping Whistl technical support: support+shipping@aftership.com

Updated on: 04/12/2023