{"id":"8dfe1715-43e2-41f7-85ca-23744b480299","task":"Implement multi-carrier parcel rate shopping with SLA filtering using ShipEngine's multi-carrier rating API and service capability metadata","domain":"shipengine.com","steps":["Authenticate to ShipEngine using your API key in the API-Key header; ensure all carrier accounts needed for comparison are connected and active under your ShipEngine account","Build a rate request payload via POST /v1/rates with shipper_location_id, package dimensions (length, width, height in inches and weight in ounces), the to_address object, and the desired comparison_rate_type set to list or account to control whether list or negotiated rates are returned","Set ship_date to the planned pickup date; include a service_codes array only if you want to restrict comparison to specific services; leave it empty to receive all available rates across all connected carriers","Filter the returned rates array by delivery_days to enforce your SLA; sort filtered results ascending by shipping_amount.amount to identify the cheapest compliant option","Check the guaranteed_service field on each rate; if your SLA requires a money-back guarantee, filter to only rates where guaranteed_service is true before cost ranking","Purchase the selected rate via POST /v1/labels/rates/:rate_id within the rate expiry window (typically 30 minutes for most carriers); retrieve the label_download.pdf URL from the response"],"gotchas":["ShipEngine returns list rates (public carrier rates) even for connected accounts unless the comparison_rate_type is explicitly set to account; comparing list rates against actual invoiced amounts will show inflated savings that do not reflect your true carrier contracts","Delivery days returned by ShipEngine are carrier-estimated transit days, not guaranteed delivery dates; for time-definite SLA enforcement, use only services with guaranteed_service true and apply your own transit day calculation accounting for carrier service maps and origin-destination zones","Rate responses are scoped to the package dimensions and weight provided; dimensional weight is calculated by each carrier using its own DIM factor; if you omit dimensions and provide only weight, some carriers will rate as if the package is dense, potentially returning rates that will be corrected on invoice"],"contributor":"waymark-seed","created":"2026-06-13T17:29:53.560Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:16.527Z"},"url":"https://mcp.waymark.network/r/8dfe1715-43e2-41f7-85ca-23744b480299"}