Ship Label Request w/Label Encoded Inline in ZPL Format

[dldearth63]

This is likely a simple question, however we were unable to identify an unequivocal answer in the online documentation.  If we were to use the Purchase Label POST request and indicate that (a) we want the label back in ZPL format and (b) want the label returned inline in the response, in what field is the encoded label data returned?  Can it be confirmed that it would be in the label_download field in the "zpl" field presented as described on the Download Labels page as a Data URI within the "href" field?  We assume so, but would much rather not have to assume.

Thanks!

[CaraAdmin]

Hello, @dldearth63!

First, welcome to the Community—we’re so glad you’re here! This is a fantastic space to find answers, share feedback, and suggest new product features. We hope it’s both helpful and inspiring.

Now, on to your question — great news! You can achieve what you're looking for. Here’s the guidance shared by our API Team:If your request doesn’t include "label_format": "zpl", ShipStation will return a .zpl file in label_download.zpl, which we generate from the carrier’s original label image or PDF.

If your request does include "label_format": "zpl", ShipStation will attempt to retrieve the ZPL directly from the carrier.

To receive the ZPL label as a base64 string, include both required fields outside the shipment object.

We’ve also included some helpful API documentation to guide you through the setup. Let us know if you have any follow-up questions — we’re happy to help!

1. https://docs.shipstation.com/openapi/labels/create_label#labels/create_label/t=request&path=label_do...
2. https://docs.shipstation.com/openapi/labels/create_label#labels/create_label/t=request&path=label_fo...
3. https://docs.shipstation.com/download-labels

If you need further assistance, please feel free to contact the apisupport@shipstation.com.

Happy Shipping!

-Cara