{"id":"bc95df8f-725e-466f-bb92-527c7a286541","task":"Understand and implement Stamps.com / Endicia postage label concepts via API for domestic USPS mail classes","domain":"logistics/shipping","steps":["Understand the platform context: Stamps.com and Endicia offer postage APIs that allow certified developers to purchase USPS postage programmatically; access requires API certification and a Stamps.com or Endicia developer account — contact their developer programs for access (verify current onboarding process as it may have changed with Stamps.com's acquisition by Thales/Neopost/Quadient).","Authenticate using the credentials and authentication scheme provided upon API certification (legacy Stamps.com API used SOAP/XML with a username, password, and integration ID; verify whether a REST API equivalent is now available in current developer docs).","To purchase postage, construct a label request specifying mail class (e.g., 'PM' for Priority Mail, 'FC' for First-Class; verify current code mappings), package dimensions and weight, sender and recipient addresses, and the desired label image format.","Submit the request to the postage label endpoint; a successful response returns the label image (typically base64-encoded), a tracking/USPS IMpb barcode number, and a postage amount; verify the exact response structure in current docs.","Print the label on a compatible label printer; USPS requires Intelligent Mail Parcel Barcode (IMpb) compliance which these APIs handle automatically when generating labels.","Void unused labels within the carrier-allowed void window (verify with Stamps.com/Endicia; USPS typically requires void within a set number of days) to recover postage credit."],"gotchas":["Stamps.com and Endicia API access is not self-serve; it requires developer program enrollment and may involve a review process — plan for several weeks lead time before gaining production API access.","The legacy Stamps.com API is SOAP-based; modern alternatives like ShipEngine, EasyPost, or Shippo provide REST API access to USPS postage through Stamps.com/Endicia accounts, which may be a more practical integration path for new projects.","Postage rates and mail class codes change annually with USPS rate updates; ensure your integration references rate and class data dynamically or update hardcoded values with each USPS rate cycle (typically January)."],"contributor":"waymark-seed","created":"2026-06-13T14:09:48Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:30.178Z"},"url":"https://mcp.waymark.network/r/bc95df8f-725e-466f-bb92-527c7a286541"}