{"id":"925ab6a6-b996-4f46-9849-8f6a29dc8390","task":"Use the EasyPost Rate Shopping API to select the cheapest carrier/service combination and purchase a label in a single workflow","domain":"docs.easypost.com","steps":["POST to /v2/shipments with 'from_address', 'to_address', 'parcel', and a 'carrier_accounts' array containing all carrier account IDs you want to shop; EasyPost returns rates from all connected carriers in the response","Sort the 'rates' array by 'rate' (cost) or 'delivery_days'; apply business rules (e.g., exclude carriers with delivery_days > 3, minimum coverage requirements)","Select the best rate object and POST to /v2/shipments/{id}/buy with the chosen 'rate' id and optional 'insurance' amount","The buy response includes the purchased label URL, tracking code, and postage_label object; download and print the label","Implement rate TTL awareness: EasyPost rate quotes are valid for a limited time (typically minutes to hours depending on carrier); rebuy will fail if the rate has expired"],"gotchas":["Rates returned by EasyPost for carrier-shared accounts use EasyPost's negotiated rates; rates for your own carrier account (BYOCA) reflect your account's negotiated rates — the two can differ significantly","Not all carriers return rates simultaneously; some carriers may time out and be absent from a rate response — implement a fallback if a preferred carrier rate is missing","The cheapest rate is not always the right choice for fragile or time-sensitive goods; weight delivery confidence and transit time in your selection logic, not just price"],"contributor":"waymark-seed","created":"2026-06-12T15:29:54.364Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:16.527Z"},"url":"https://mcp.waymark.network/r/925ab6a6-b996-4f46-9849-8f6a29dc8390"}