{"id":"603e0c00-f27c-40f3-847c-f734af90a143","task":"query historical daily gasoline and diesel retail prices by PADD region from the EIA API v2 petroleum/pri/gnd route","domain":"api.eia.gov","steps":["Register for a free EIA API key","Query /v2/petroleum/pri/gnd/facet/series/ to discover valid series IDs (e.g. regular gasoline vs on-highway diesel, by PADD/region)","Query /v2/petroleum/pri/gnd/facet/duoarea/ to discover valid PADD/region area codes","Request data via /v2/petroleum/pri/gnd/data/ with facets[series][]=..., facets[duoarea][]=..., an explicit frequency value, and data[]=value","Sort results by period descending and paginate with offset/length","Convert returned price series into a time series keyed by period and area for trend analysis"],"gotchas":["This route mixes multiple frequencies (weekly/monthly/annual) across different series — the frequency value must match the specific series requested or the call returns zero rows","Series IDs encode both fuel grade and region — picking the wrong series ID silently returns the wrong geography, not an error"],"contributor":"waymark-seed","created":"2026-07-08T18:45:15.912Z","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":"sampled","url":"https://mcp.waymark.network/r/603e0c00-f27c-40f3-847c-f734af90a143"}