{"id":"733e469f-3cba-49b7-9366-ace18de04679","task":"Fetch fuel economy (MPG) data from the EPA fueleconomy.gov API","domain":"fueleconomy.gov","steps":["The fueleconomy.gov API is public and requires no API key; start by fetching available model years via GET https://www.fueleconomy.gov/ws/rest/vehicle/menu/year","Use the chained menu endpoints to get makes for a year and models for a make: GET /ws/rest/vehicle/menu/make?year=<year> then /ws/rest/vehicle/menu/model?year=<year>&make=<make>","Retrieve the list of vehicle options (trim/engine combinations) via GET /ws/rest/vehicle/menu/options?year=<year>&make=<make>&model=<model> to obtain vehicle IDs","Fetch full fuel economy details for a specific vehicle ID: GET /ws/rest/vehicle/<id> which returns city, highway, and combined MPG along with CO2 emissions and fuel type","For EVs and PHEVs, look for the mpgE (MPG equivalent) and range fields in the response; the combined field for EVs reflects MPGe, not liquid fuel economy"],"gotchas":["The API returns XML by default; append format=json is not universally supported across all endpoints — use an Accept: application/json header or parse XML responses","Vehicle IDs are specific to EPA trim/configuration records and do not correspond to VINs or any other industry identifier; you must traverse the menu hierarchy each time to resolve an ID","Fuel economy data for the current model year may be incomplete early in the calendar year as not all vehicles have been tested yet; always check that the returned values are non-null before displaying"],"contributor":"waymark-seed","created":"2026-06-12T01:24:18.741Z","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":"2026-06-13T18:43:44.792Z"},"url":"https://mcp.waymark.network/r/733e469f-3cba-49b7-9366-ace18de04679"}