{"openapi":"3.1.0","info":{"title":"Propane & LPG Tank API","version":"1.0.0","description":"Propane and LPG tank maths as an API, computed locally and deterministically — the usable-fill, energy and burn-time numbers a homeowner, RV-er, grill-master or HVAC tech works out at the tank. The tank endpoint turns a tank size into real numbers: liquid propane is 4.24 lb per gallon and holds 91,452 BTU per gallon (about 21,569 BTU per pound), so a 20 lb barbecue cylinder carries roughly 4.7 gallons and 431,000 BTU. It knows the two ways tanks are sized — a portable cylinder (20, 30, 40 lb) is rated by the propane weight it holds, while a bulk tank (100, 250, 500, 1000 gal) is filled to only 80 % of its water capacity to leave room for expansion, so a 500-gallon tank actually holds 400 gallons of propane and about 36.6 million BTU. The burntime endpoint divides that energy by an appliance’s BTU-per-hour input rating to give run time: that same 20 lb cylinder runs a 30,000 BTU/hr patio heater about 14 hours, and an optional hours-per-day turns it into days. The refill endpoint costs a fill from a price per gallon, gives the cost per 100,000 BTU so you can compare propane to natural gas or electricity, and — with an appliance rating — the running cost per hour. Everything is computed locally and deterministically, so it is instant and private. Ideal for home-energy, HVAC, RV, off-grid, grilling and outdoor-living app developers, fuel-cost and tank-monitor tools, and propane-delivery calculators. Pure local computation — no key, no third-party service, instant. US units. Live, nothing stored. 3 compute endpoints. For vehicle fuel economy or the ideal gas law use a different API.","contact":{"name":"PremiumApi","url":"https://www.oanor.com/by/premiumapi"}},"servers":[{"url":"https://api.oanor.com/propane-api","description":"oanor gateway"}],"tags":[{"name":"Propane"},{"name":"Meta"}],"components":{"securitySchemes":{"oanorKey":{"type":"apiKey","in":"header","name":"x-oanor-key","description":"Get your key at https://www.oanor.com/developer/keys"}}},"security":[{"oanorKey":[]}],"paths":{"/v1/burntime":{"get":{"operationId":"get_v1_burntime","tags":["Propane"],"summary":"Appliance run time","description":"","parameters":[{"name":"tank_size","in":"query","required":true,"description":"Tank size","schema":{"type":"string"},"example":"20"},{"name":"appliance_btu","in":"query","required":true,"description":"Appliance input rating (BTU/hr)","schema":{"type":"string"},"example":"30000"},{"name":"unit","in":"query","required":false,"description":"lb or gal","schema":{"type":"string"},"example":"lb"},{"name":"hours_per_day","in":"query","required":false,"description":"Hours of use per day (gives run_days)","schema":{"type":"string"},"example":"4"}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"note":"Run time = total BTU ÷ the appliance's BTU/hr input rating. A 20 lb cylinder (~431,000 BTU) runs a 30,000 BTU/hr patio heater about 14 hours.","inputs":{"unit":"lb","tank_size":20,"appliance_btu":30000},"run_days":3.6,"run_hours":14.39,"total_btu":431653,"usable_propane_gal":4.72,"propane_gal_per_hour":0.328},"meta":{"timestamp":"2026-06-06T07:14:06.090Z","request_id":"de265944-b688-4a93-a2b2-e1fa0632e786"},"status":"ok","message":"Burn time","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/refill":{"get":{"operationId":"get_v1_refill","tags":["Propane"],"summary":"Refill + operating cost","description":"","parameters":[{"name":"tank_size","in":"query","required":true,"description":"Tank size","schema":{"type":"string"},"example":"500"},{"name":"price_per_gallon","in":"query","required":true,"description":"Propane price per gallon","schema":{"type":"string"},"example":"3"},{"name":"unit","in":"query","required":false,"description":"lb or gal","schema":{"type":"string"},"example":"gal"},{"name":"appliance_btu","in":"query","required":false,"description":"Appliance BTU/hr (gives cost/hour)","schema":{"type":"string"},"example":"30000"}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"note":"Fill cost = usable gallons × price per gallon. Cost per 100k BTU lets you compare propane to natural gas or electricity. Pass appliance_btu to also get the running cost per hour.","inputs":{"unit":"gal","tank_size":500,"price_per_gallon":3},"fill_cost":1200,"run_hours":1219.36,"appliance_btu":30000,"cost_per_hour":0.9841,"cost_per_100k_btu":3.2804,"usable_propane_gal":400},"meta":{"timestamp":"2026-06-06T07:14:06.184Z","request_id":"6d0204fc-200a-4f9c-9ad6-06d58a9049e4"},"status":"ok","message":"Refill cost","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/tank":{"get":{"operationId":"get_v1_tank","tags":["Propane"],"summary":"Usable propane + BTU energy","description":"","parameters":[{"name":"tank_size","in":"query","required":true,"description":"Tank size","schema":{"type":"string"},"example":"20"},{"name":"unit","in":"query","required":false,"description":"lb (cylinder weight) or gal (bulk water capacity)","schema":{"type":"string"},"example":"lb"}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"note":"Liquid propane is 4.24 lb/gal and holds 91,452 BTU/gal (21,569 BTU/lb). Portable cylinders are rated by the propane weight they hold; bulk tanks are filled to 80 % of their water capacity to leave room for expansion.","basis":"cylinder rated by propane weight","inputs":{"unit":"lb","tank_size":20},"total_btu":431653,"usable_propane_lb":20,"usable_propane_gal":4.72},"meta":{"timestamp":"2026-06-06T07:14:06.284Z","request_id":"96961aaa-d03c-4ff5-83b5-38cdcea2a98f"},"status":"ok","message":"Tank energy","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/meta":{"get":{"operationId":"get_v1_meta","tags":["Meta"],"summary":"Spec","description":"","parameters":[],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"notes":"US units. unit=lb treats tank_size as a cylinder's propane weight (20/30/40 lb); unit=gal treats it as a bulk tank's water capacity, filled to 80 %. 4.24 lb/gal, 91,452 BTU/gal. For vehicle fuel economy or the ideal gas law use a different API.","service":"propane-api","endpoints":{"GET /v1/meta":"This document.","GET /v1/tank":"Usable propane (lb & gal) and total BTU for a cylinder or bulk tank.","GET /v1/refill":"Fill cost and operating cost per hour from a price per gallon.","GET /v1/burntime":"How long a tank runs an appliance of a given BTU/hr rating."},"description":"Propane / LPG tank maths: usable fill, BTU energy content, appliance burn time, and refill economics."},"meta":{"timestamp":"2026-06-06T07:14:06.387Z","request_id":"73f3eeff-b49e-4443-82fb-99e42b652933"},"status":"ok","message":"Meta","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}}},"x-oanor-pricing":[{"slug":"free","name":"Free","price_cents_month":0,"monthly_call_quota":7400,"rps_limit":2,"hard_limit":true},{"slug":"starter","name":"Starter","price_cents_month":440,"monthly_call_quota":54000,"rps_limit":6,"hard_limit":true},{"slug":"pro","name":"Pro","price_cents_month":1210,"monthly_call_quota":225000,"rps_limit":15,"hard_limit":true},{"slug":"mega","name":"Mega","price_cents_month":3850,"monthly_call_quota":1310000,"rps_limit":40,"hard_limit":true}],"x-oanor-marketplace-url":"https://www.oanor.com/api/propane-api"}