Binary Labels

Download Label returns a successful body as binary, not a JSON envelope. Branch on HTTP status and actual Content-Type before handling the body.

Declared binary types

The current 200 response declares only application/pdf and application/zpl; all three ZPL printer resolutions (format 2, 3, and 4) share application/zpl. Stream bytes where your client supports it; do not log the binary body. Select the local filename yourself: the public contract does not declare Content-Disposition, a filename, cache behavior, or storage lifetime.

Protect stored shipping Labels under your application's data policy. Download Label is the documented binary operation; no direct asset-URL workflow is public.

Pending response

202 means pending/still generating only. There is no public polling interval, Retry-After, or eventual-success guarantee. Preserve the identifier, avoid a tight loop, and use an application-owned cadence.

For parameters and documented errors, see Download a Label and Label Errors.