{"service":"Utility Tariff API","what_it_does":"Returns exact residential electric rates and itemized bills for Arizona utilities, computed from filed tariff documents rather than estimates. Every response cites the filing it came from.","coverage":{"utilities":["Salt River Project Agricultural Improvement and Power District"],"plans":{"srp:E-21":[{"from":"2026-05","through":"2026-10"}],"srp:E-26":[{"from":"2025-11","through":"2026-04"},{"from":"2026-05","through":"2026-10"}],"srp:E-28":[{"from":"2025-11","through":null}]},"customer_class":"residential","note":"Each plan lists the billing-cycle windows on record. Cycles outside them return HTTP 422."},"endpoints":{"GET /v1/tariff/plans":"List available plans and whether each can be billed. Free.","GET /v1/tariff/rate":"Per-kWh rate at a moment in time, with component breakdown.","POST /v1/tariff/bill":"Itemized bill from usage intervals."},"docs":"/docs","openapi":"/openapi.json","payment":{"protocol":"x402","network":"eip155:84532","note":"Paid endpoints return HTTP 402 with terms in the payment-required header."},"operator":"Killion Apps"}