Purchase all labels for the day via POST to /v1/transactions; collect the transaction IDs for all USPS shipments to be manifested
POST to /v1/manifests with 'carrier_account' (your USPS carrier account ID), 'shipment_date' (today's date in ISO 8601), 'address_from' (the origin address), and 'transactions' array of transaction IDs
Poll GET /v1/manifests/{id} until the 'status' field transitions from 'QUEUED' to 'SUCCESS'; then download the manifest from the 'label_url' in the response
Print the SCAN form and present it to the USPS driver at pickup; the driver scans the single barcode to accept all listed parcels into the postal stream at once
Create a separate manifest per origin address; USPS requires the address_from to match the actual pickup/drop-off location
Known gotchas
SCAN forms are required for USPS to accept bulk drop-offs efficiently; without a manifest, each package must be individually scanned, and high-volume drops may be refused
A manifest cannot be amended after creation; if additional labels are purchased after manifest creation, a new manifest must be generated for those packages
Not all carriers support Shippo manifests; Canada Post, Australia Post, and DHL eCommerce have their own manifest formats — check Shippo's carrier support list for manifest eligibility
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp