Home Energy Calculators
Cost per million BTU of delivered heat for resistance, heat pump, gas, propane and heating oil furnaces, from your prices.
TradingLiveeip155:8453Exactvia cdp
EnergyHeatingHeat-pumpFuel-costCalculator
Calls · 30d
1
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far.
$24.31
Verified settled volume
1,175 settlements proven x402 by their on-chain EIP-3009 marker.
$0.020
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-10-20 20:33Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xb531320805C5BED1D46AEaDcF4F008FDF172DBDaThe wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Provider
The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.
Live 402 challenge
Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.
{
"error": "Payment required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
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"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "base",
"mimeType": "application/json",
"resource": "https://home-energy-calc.x402tookit.com/heating-cost-compare",
"description": "Cost per million BTU of delivered heat for resistance, heat pump, gas, propane and heating oil furnaces, from your prices.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"gasPerTherm": 1.5,
"oilPerGallon": 4,
"annualHeatMMBtu": 60,
"propanePerGallon": 3.2,
"electricityPerKwh": 0.16
}
},
"output": {
"asOf": "2026-10-11T14:31:35.911Z",
"source": "computed locally",
"reasons": [
"Cost per delivered MMBtu = fuel price per MMBtu of energy content / efficiency (or COP).",
"Heat contents: 1 kWh = 3,412 BTU; 1 therm = 100,000 BTU; propane 91,452 BTU/gal and heating oil 137,381 BTU/gal (EIA). A heat pump at COP 3 beats the gas furnace while electricity costs under 0.1616 p…"
],
"summary": "Cheapest delivered heat: heat pump at 15.63 per million BTU (938 a year for 60 MMBtu); most expensive: electric resistance at 46.89.",
"verdict": "COMPUTED",
"degraded": false,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"equipment cost, maintenance, installation and duct losses",
"heat pump performance falling in very cold weather: the COP is a seasonal average you must choose for your climate",
"…2 more"
],
"systemsRankedCheapestFirst": [
{
"note": "seasonal COP 3",
"system": "heat pump",
"yearlyCost": 938,
"assumedEfficiency": 3,
"relativeToCheapest": 1,
"costPerMMBtuDelivered": 15.63
},
{
"note": "AFUE 0.95",
"system": "natural gas furnace",
"yearlyCost": 947,
"assumedEfficiency": 0.95,
"relativeToCheapest": 1.01,
"costPerMMBtuDelivered": 15.79
}
],
"heatPumpBreakEvenElectricityPerKwhVsGas": 0.1616
}
},
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"scheme": "exact",
"network": "solana",
"mimeType": "application/json",
"resource": "https://home-energy-calc.x402tookit.com/heating-cost-compare",
"description": "Cost per million BTU of delivered heat for resistance, heat pump, gas, propane and heating oil furnaces, from your prices.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"gasPerTherm": 1.5,
"oilPerGallon": 4,
"annualHeatMMBtu": 60,
"propanePerGallon": 3.2,
"electricityPerKwh": 0.16
}
},
"output": {
"asOf": "2026-10-11T14:31:35.911Z",
"source": "computed locally",
"reasons": [
"Cost per delivered MMBtu = fuel price per MMBtu of energy content / efficiency (or COP).",
"Heat contents: 1 kWh = 3,412 BTU; 1 therm = 100,000 BTU; propane 91,452 BTU/gal and heating oil 137,381 BTU/gal (EIA). A heat pump at COP 3 beats the gas furnace while electricity costs under 0.1616 p…"
],
"summary": "Cheapest delivered heat: heat pump at 15.63 per million BTU (938 a year for 60 MMBtu); most expensive: electric resistance at 46.89.",
"verdict": "COMPUTED",
"degraded": false,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"equipment cost, maintenance, installation and duct losses",
"heat pump performance falling in very cold weather: the COP is a seasonal average you must choose for your climate",
"…2 more"
],
"systemsRankedCheapestFirst": [
{
"note": "seasonal COP 3",
"system": "heat pump",
"yearlyCost": 938,
"assumedEfficiency": 3,
"relativeToCheapest": 1,
"costPerMMBtuDelivered": 15.63
},
{
"note": "AFUE 0.95",
"system": "natural gas furnace",
"yearlyCost": 947,
"assumedEfficiency": 0.95,
"relativeToCheapest": 1.01,
"costPerMMBtuDelivered": 15.79
}
],
"heatPumpBreakEvenElectricityPerKwhVsGas": 0.1616
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
},
{
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "polygon",
"mimeType": "application/json",
"resource": "https://home-energy-calc.x402tookit.com/heating-cost-compare",
"description": "Cost per million BTU of delivered heat for resistance, heat pump, gas, propane and heating oil furnaces, from your prices.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"gasPerTherm": 1.5,
"oilPerGallon": 4,
"annualHeatMMBtu": 60,
"propanePerGallon": 3.2,
"electricityPerKwh": 0.16
}
},
"output": {
"asOf": "2026-10-11T14:31:35.911Z",
"source": "computed locally",
"reasons": [
"Cost per delivered MMBtu = fuel price per MMBtu of energy content / efficiency (or COP).",
"Heat contents: 1 kWh = 3,412 BTU; 1 therm = 100,000 BTU; propane 91,452 BTU/gal and heating oil 137,381 BTU/gal (EIA). A heat pump at COP 3 beats the gas furnace while electricity costs under 0.1616 p…"
],
"summary": "Cheapest delivered heat: heat pump at 15.63 per million BTU (938 a year for 60 MMBtu); most expensive: electric resistance at 46.89.",
"verdict": "COMPUTED",
"degraded": false,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"equipment cost, maintenance, installation and duct losses",
"heat pump performance falling in very cold weather: the COP is a seasonal average you must choose for your climate",
"…2 more"
],
"systemsRankedCheapestFirst": [
{
"note": "seasonal COP 3",
"system": "heat pump",
"yearlyCost": 938,
"assumedEfficiency": 3,
"relativeToCheapest": 1,
"costPerMMBtuDelivered": 15.63
},
{
"note": "AFUE 0.95",
"system": "natural gas furnace",
"yearlyCost": 947,
"assumedEfficiency": 0.95,
"relativeToCheapest": 1.01,
"costPerMMBtuDelivered": 15.79
}
],
"heatPumpBreakEvenElectricityPerKwhVsGas": 0.1616
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1,
"alsoAvailable": {
"llms": "https://home-energy-calc.x402tookit.com/llms.txt",
"catalog": "https://home-energy-calc.x402tookit.com/catalog",
"message": "Home Energy Calculators has 9 pay-per-call endpoints (Home energy math for agents: bills, appliance loads, solar sizing, heat loss, HVAC load checks, insulation, water heating, EV charging and fuel cost.), from $0.02 a call. See the full menu and send your agents our way.",
"openapi": "https://home-energy-calc.x402tookit.com/openapi.json",
"related": [
{
"url": "https://home-energy-calc.x402tookit.com/household-load",
"path": "/household-load",
"what": "Total a list of appliances (watts, hours a day, quantity) into kWh and cost per day, mont…",
"price": "$0.02"
},
{
"url": "https://home-energy-calc.x402tookit.com/hvac-sizing",
"path": "/hvac-sizing",
"what": "Room air-conditioner BTU from floor area (ENERGY STAR chart), tons, and an under- or over…",
"price": "$0.02"
},
{
"url": "https://home-energy-calc.x402tookit.com/insulation-r-value",
"path": "/insulation-r-value",
"what": "R-value and U-factor of a wall or roof assembly from layers and thickness, with a framing…",
"price": "$0.02"
}
]
}
}Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.02USDC≈ $0.02 USD
on Base · exact scheme
Pay 0.02 USDC on Base to 0xb531…2DBDa. The signed payment is good for 5 minutes.
- Paid to
- 0xb531…2DBDa
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 20000 smallest units
20000units
on solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · exact scheme
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- DUPiup…eEm8s
- Token contract
- EPjFWd…TDt1v
- Payment window
- 5 minutes
20000units
on Polygon · exact scheme
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xb531…2DBDa
- Token contract
- 0x3c49…c3359
- Payment window
- 5 minutes
20000units
on Arbitrum · exact scheme
That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.
- Paid to
- 0xb531…2DBDa
- Token contract
- 0xaf88…e5831
- Payment window
- 5 minutes
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
},
{
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "D6ZhtNQ5nT9ZnTHUbqXZsTx5MH2rPFiBBggX4hY1WePM"
},
"payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
"amount": "20000",
"scheme": "exact",
"network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
"maxTimeoutSeconds": 300
},
{
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:137",
"maxTimeoutSeconds": 300
},
{
"asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:42161",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"gasPerTherm": 1.5,
"oilPerGallon": 4,
"annualHeatMMBtu": 60,
"propanePerGallon": 3.2,
"electricityPerKwh": 0.16
}
},
"output": {
"type": "json",
"example": {
"asOf": "2026-10-11T14:31:35.911Z",
"source": "computed locally",
"reasons": [
"Cost per delivered MMBtu = fuel price per MMBtu of energy content / efficiency (or COP).",
"Heat contents: 1 kWh = 3,412 BTU; 1 therm = 100,000 BTU; propane 91,452 BTU/gal and heating oil 137,381 BTU/gal (EIA). A heat pump at COP 3 beats the gas furnace while electricity costs under 0.1616 p…"
],
"summary": "Cheapest delivered heat: heat pump at 15.63 per million BTU (938 a year for 60 MMBtu); most expensive: electric resistance at 46.89.",
"verdict": "COMPUTED",
"degraded": false,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"equipment cost, maintenance, installation and duct losses",
"heat pump performance falling in very cold weather: the COP is a seasonal average you must choose for your climate",
"…2 more"
],
"systemsRankedCheapestFirst": [
{
"note": "seasonal COP 3",
"system": "heat pump",
"yearlyCost": 938,
"assumedEfficiency": 3,
"relativeToCheapest": 1,
"costPerMMBtuDelivered": 15.63
},
{
"note": "AFUE 0.95",
"system": "natural gas furnace",
"yearlyCost": 947,
"assumedEfficiency": 0.95,
"relativeToCheapest": 1.01,
"costPerMMBtuDelivered": 15.79
}
],
"heatPumpBreakEvenElectricityPerKwhVsGas": 0.1616
}
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method"
],
"properties": {
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"type": "object",
"required": [],
"properties": {
"gasAfue": {
"type": "number",
"description": "Gas furnace efficiency 0.5 to 0.99 (default 0.95)"
},
"oilAfue": {
"type": "number",
"description": "Oil furnace efficiency 0.5 to 0.99 (default 0.85)"
},
"gasPerTherm": {
"type": "number",
"description": "Natural gas price per therm (1 therm = 100,000 BTU)"
},
"heatPumpCop": {
"type": "number",
"description": "Seasonal heat pump COP, 1.5 to 6 (default 3)"
},
"propaneAfue": {
"type": "number",
"description": "Propane furnace efficiency 0.5 to 0.99 (default 0.95)"
},
"oilPerGallon": {
"type": "number",
"description": "Heating oil price per gallon (137,381 BTU/gal)"
},
"annualHeatMMBtu": {
"type": "number",
"description": "Yearly heat your home needs in million BTU (see /heat-loss), for yearly cost"
},
"propanePerGallon": {
"type": "number",
"description": "Propane price per gallon (91,452 BTU/gal)"
},
"electricityPerKwh": {
"type": "number",
"description": "Electricity price per kWh (gives resistance and heat pump)"
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"properties": {
"asOf": {
"type": [
"null",
"string"
]
},
"source": {
"type": [
"null",
"string"
]
},
"reasons": {
"type": [
"array",
"null"
],
"items": {
"type": "string"
}
},
"summary": {
"type": [
"null",
"string"
]
},
"verdict": {
"type": [
"null",
"string"
]
},
"degraded": {
"type": [
"boolean",
"null"
]
},
"disclaimer": {
"type": [
"null",
"string"
]
},
"notChecked": {
"type": [
"array",
"null"
],
"items": {
"type": "string"
}
},
"systemsRankedCheapestFirst": {
"type": [
"array",
"null"
],
"items": {
"type": "object",
"properties": {
"note": {
"type": [
"null",
"string"
]
},
"system": {
"type": [
"null",
"string"
]
},
"yearlyCost": {
"type": [
"null",
"number"
]
},
"assumedEfficiency": {
"type": [
"null",
"number"
]
},
"relativeToCheapest": {
"type": [
"null",
"number"
]
},
"costPerMMBtuDelivered": {
"type": [
"null",
"number"
]
}
}
}
},
"heatPumpBreakEvenElectricityPerKwhVsGas": {
"type": [
"null",
"number"
]
}
}
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-10-20 20:33Z
- Last indexed by Roundhouse
- 2026-10-22 12:40Z
- Last enriched (probe, favicon, geo)
- 2026-10-21 00:15Z
- x402 version
- 2
- Max timeout
- 300s
- Liveness probe
- HTTP 402
Hand this page to an agent
Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.
GET api.roundhouseai.io/v0/endpoints
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 4 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.
Show the promptHide the prompt
Using Roundhouse, look up the x402 service Home Energy Calculators and tell me whether it is worth paying: what a call costs, whether the endpoint answered when last probed, and what its payment record actually shows. curl -s 'https://api.roundhouseai.io/v0/endpoints?q=Home%20Energy%20Calculators' curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>' Then call it: read the price from the live 402 at https://home-energy-calc.x402tookit.com/heating-cost-compare, never from a cached figure, and pay with an x402 client. The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except /v0/unified* and /v0/endpoints. Either pay over x402 (mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.