{"id":"dcc890d0-5d8f-44ee-b0e7-20ad3ce4881d","task":"Use the USPS Addresses v3 API to standardize and validate a US address and look up ZIP+4","domain":"developers.usps.com","steps":["Obtain a Bearer token via OAuth 2.0 client credentials flow at the USPS token endpoint","GET /v3/addresses with query parameters 'streetAddress', 'city', 'state', and optionally 'ZIPCode'; USPS returns a standardized address in USPS delivery-point format with ZIP+4 appended","Check the response for 'addressAdditionalInfo' and 'DPV' (Delivery Point Validation) fields to confirm the address is a valid deliverable point","Use GET /v3/city-state with a ZIP code to perform reverse lookup (ZIP to city/state); use GET /v3/zipcode with city and state to find the correct ZIP for an input","USPS standardization enforces CASS-certified formatting; use the returned 'streetAddressAbbreviation' and 'cityAbbreviation' values when storing addresses for carrier label generation"],"gotchas":["USPS address standardization is domestic US only; do not submit international addresses to the v3 Addresses endpoint","The USPS API Access Control initiative launching April 2026 may require additional scopes or access provisioning; monitor the developers.usps.com portal for announcements","A valid DPV confirmation does not guarantee the recipient exists at that address — only that the address is a recognized USPS delivery point"],"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":"2026-06-13T18:44:37.183Z"},"url":"https://mcp.waymark.network/r/dcc890d0-5d8f-44ee-b0e7-20ad3ce4881d"}