Home Energy Calculators
Electric vehicle charging time, cost and range added from battery size, charge levels, charger power or circuit, and price.
TradingLiveeip155:8453Exactvia cdp
EnergyEvChargingElectric-vehicleCalculator
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"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "base",
"mimeType": "application/json",
"resource": "https://home-energy-calc.x402tookit.com/ev-charging",
"description": "Electric vehicle charging time, cost and range added from battery size, charge levels, charger power or circuit, and price.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"batteryKwh": 60,
"endPercent": 80,
"breakerAmps": 40,
"milesPerKwh": 3.5,
"pricePerKwh": 0.16,
"startPercent": 20
}
},
"output": {
"asOf": "2026-10-11T14:31:35.383Z",
"cost": 6.4,
"hours": 5.21,
"source": "computed locally",
"lossKwh": 4,
"minutes": 313,
"reasons": [
"Time = energy from the wall / charger power; energy from the wall = energy added / efficiency.",
"A continuous load (3 hours or more) may use only 80% of a breaker's rating, which is why a 40 A breaker supports 32 A."
],
"summary": "Charging 20% to 80% of a 60 kWh battery adds 36 kWh (40 kWh from the wall at 90% efficiency); at 7.68 kW (40 A breaker x 80% continuous = 32 A at 240 V) that takes about 5.2 hours. Cost 6.4 at 0.16 pe…",
"verdict": "COMPUTED",
"degraded": false,
"chargerKw": 7.68,
"batteryKwh": 60,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"endPercent": 80,
"milesAdded": 126,
"notChecked": [
"charge taper: batteries slow down above about 80% and in the cold, so the last percent takes longer than this linear estimate",
"the car's onboard charger limit (many cars accept only 7 to 11 kW AC regardless of the circuit)",
"…2 more"
],
"circuitAmps": 32,
"costPerMile": 0.0508,
"circuitVolts": 240,
"startPercent": 20,
"chargerSource": "40 A breaker x 80% continuous = 32 A at 240 V",
"energyFromWallKwh": 40,
"chargingEfficiency": 0.9,
"energyAddedToBatteryKwh": 36
}
},
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
},
{
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "BFK9TLC3edb13K6v4YyH3DwPb5DSUpkWvb7XnqCL9b4F"
},
"payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
"scheme": "exact",
"network": "solana",
"mimeType": "application/json",
"resource": "https://home-energy-calc.x402tookit.com/ev-charging",
"description": "Electric vehicle charging time, cost and range added from battery size, charge levels, charger power or circuit, and price.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"batteryKwh": 60,
"endPercent": 80,
"breakerAmps": 40,
"milesPerKwh": 3.5,
"pricePerKwh": 0.16,
"startPercent": 20
}
},
"output": {
"asOf": "2026-10-11T14:31:35.383Z",
"cost": 6.4,
"hours": 5.21,
"source": "computed locally",
"lossKwh": 4,
"minutes": 313,
"reasons": [
"Time = energy from the wall / charger power; energy from the wall = energy added / efficiency.",
"A continuous load (3 hours or more) may use only 80% of a breaker's rating, which is why a 40 A breaker supports 32 A."
],
"summary": "Charging 20% to 80% of a 60 kWh battery adds 36 kWh (40 kWh from the wall at 90% efficiency); at 7.68 kW (40 A breaker x 80% continuous = 32 A at 240 V) that takes about 5.2 hours. Cost 6.4 at 0.16 pe…",
"verdict": "COMPUTED",
"degraded": false,
"chargerKw": 7.68,
"batteryKwh": 60,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"endPercent": 80,
"milesAdded": 126,
"notChecked": [
"charge taper: batteries slow down above about 80% and in the cold, so the last percent takes longer than this linear estimate",
"the car's onboard charger limit (many cars accept only 7 to 11 kW AC regardless of the circuit)",
"…2 more"
],
"circuitAmps": 32,
"costPerMile": 0.0508,
"circuitVolts": 240,
"startPercent": 20,
"chargerSource": "40 A breaker x 80% continuous = 32 A at 240 V",
"energyFromWallKwh": 40,
"chargingEfficiency": 0.9,
"energyAddedToBatteryKwh": 36
}
},
"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/ev-charging",
"description": "Electric vehicle charging time, cost and range added from battery size, charge levels, charger power or circuit, and price.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"batteryKwh": 60,
"endPercent": 80,
"breakerAmps": 40,
"milesPerKwh": 3.5,
"pricePerKwh": 0.16,
"startPercent": 20
}
},
"output": {
"asOf": "2026-10-11T14:31:35.383Z",
"cost": 6.4,
"hours": 5.21,
"source": "computed locally",
"lossKwh": 4,
"minutes": 313,
"reasons": [
"Time = energy from the wall / charger power; energy from the wall = energy added / efficiency.",
"A continuous load (3 hours or more) may use only 80% of a breaker's rating, which is why a 40 A breaker supports 32 A."
],
"summary": "Charging 20% to 80% of a 60 kWh battery adds 36 kWh (40 kWh from the wall at 90% efficiency); at 7.68 kW (40 A breaker x 80% continuous = 32 A at 240 V) that takes about 5.2 hours. Cost 6.4 at 0.16 pe…",
"verdict": "COMPUTED",
"degraded": false,
"chargerKw": 7.68,
"batteryKwh": 60,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"endPercent": 80,
"milesAdded": 126,
"notChecked": [
"charge taper: batteries slow down above about 80% and in the cold, so the last percent takes longer than this linear estimate",
"the car's onboard charger limit (many cars accept only 7 to 11 kW AC regardless of the circuit)",
"…2 more"
],
"circuitAmps": 32,
"costPerMile": 0.0508,
"circuitVolts": 240,
"startPercent": 20,
"chargerSource": "40 A breaker x 80% continuous = 32 A at 240 V",
"energyFromWallKwh": 40,
"chargingEfficiency": 0.9,
"energyAddedToBatteryKwh": 36
}
},
"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/heat-loss",
"path": "/heat-loss",
"what": "Heat loss of a building in BTU/h and watts from surface areas and R-values plus air leaka…",
"price": "$0.02"
},
{
"url": "https://home-energy-calc.x402tookit.com/heating-cost-compare",
"path": "/heating-cost-compare",
"what": "Cost per million BTU of delivered heat for resistance, heat pump, gas, propane and heatin…",
"price": "$0.02"
},
{
"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"
}
]
}
}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": {
"batteryKwh": 60,
"endPercent": 80,
"breakerAmps": 40,
"milesPerKwh": 3.5,
"pricePerKwh": 0.16,
"startPercent": 20
}
},
"output": {
"type": "json",
"example": {
"asOf": "2026-10-11T14:31:35.383Z",
"cost": 6.4,
"hours": 5.21,
"source": "computed locally",
"lossKwh": 4,
"minutes": 313,
"reasons": [
"Time = energy from the wall / charger power; energy from the wall = energy added / efficiency.",
"A continuous load (3 hours or more) may use only 80% of a breaker's rating, which is why a 40 A breaker supports 32 A."
],
"summary": "Charging 20% to 80% of a 60 kWh battery adds 36 kWh (40 kWh from the wall at 90% efficiency); at 7.68 kW (40 A breaker x 80% continuous = 32 A at 240 V) that takes about 5.2 hours. Cost 6.4 at 0.16 pe…",
"verdict": "COMPUTED",
"degraded": false,
"chargerKw": 7.68,
"batteryKwh": 60,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"endPercent": 80,
"milesAdded": 126,
"notChecked": [
"charge taper: batteries slow down above about 80% and in the cold, so the last percent takes longer than this linear estimate",
"the car's onboard charger limit (many cars accept only 7 to 11 kW AC regardless of the circuit)",
"…2 more"
],
"circuitAmps": 32,
"costPerMile": 0.0508,
"circuitVolts": 240,
"startPercent": 20,
"chargerSource": "40 A breaker x 80% continuous = 32 A at 240 V",
"energyFromWallKwh": 40,
"chargingEfficiency": 0.9,
"energyAddedToBatteryKwh": 36
}
}
},
"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": [
"batteryKwh",
"startPercent",
"endPercent"
],
"properties": {
"level": {
"type": "string",
"description": "Or level1 (120 V, 12 A) or level2 (240 V, 32 A)"
},
"volts": {
"type": "number",
"description": "Circuit voltage with breakerAmps, 100 to 480 (default 240)"
},
"chargerKw": {
"type": "number",
"description": "Charger power in kW delivered to the car's charger, 0.5 to 400 (or use breakerAmps, or level)"
},
"batteryKwh": {
"type": "number",
"description": "Usable battery capacity in kWh, 5 to 300"
},
"endPercent": {
"type": "number",
"description": "State of charge wanted, 1 to 100 (above the start)"
},
"breakerAmps": {
"type": "number",
"description": "Or the circuit breaker size in amps; a continuous load may use 80% of it (voltage from volts, default 240)"
},
"milesPerKwh": {
"type": "number",
"description": "Vehicle efficiency in miles per kWh, 0.5 to 8, for range added"
},
"pricePerKwh": {
"type": "number",
"description": "Electricity price per kWh, for cost"
},
"startPercent": {
"type": "number",
"description": "State of charge at the start, 0 to 99"
},
"chargingEfficiency": {
"type": "number",
"description": "Wall-to-battery efficiency 0.7 to 1 (default 0.90 for AC charging)"
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"properties": {
"asOf": {
"type": [
"null",
"string"
]
},
"cost": {
"type": [
"null",
"number"
]
},
"hours": {
"type": [
"null",
"number"
]
},
"source": {
"type": [
"null",
"string"
]
},
"lossKwh": {
"type": [
"null",
"number"
]
},
"minutes": {
"type": [
"null",
"number"
]
},
"reasons": {
"type": [
"array",
"null"
],
"items": {
"type": "string"
}
},
"summary": {
"type": [
"null",
"string"
]
},
"verdict": {
"type": [
"null",
"string"
]
},
"degraded": {
"type": [
"boolean",
"null"
]
},
"chargerKw": {
"type": [
"null",
"number"
]
},
"batteryKwh": {
"type": [
"null",
"number"
]
},
"disclaimer": {
"type": [
"null",
"string"
]
},
"endPercent": {
"type": [
"null",
"number"
]
},
"milesAdded": {
"type": [
"null",
"number"
]
},
"notChecked": {
"type": [
"array",
"null"
],
"items": {
"type": "string"
}
},
"circuitAmps": {
"type": [
"null",
"number"
]
},
"costPerMile": {
"type": [
"null",
"number"
]
},
"circuitVolts": {
"type": [
"null",
"number"
]
},
"startPercent": {
"type": [
"null",
"number"
]
},
"chargerSource": {
"type": [
"null",
"string"
]
},
"energyFromWallKwh": {
"type": [
"null",
"number"
]
},
"chargingEfficiency": {
"type": [
"null",
"number"
]
},
"energyAddedToBatteryKwh": {
"type": [
"null",
"number"
]
}
}
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-10-20 20:33Z
- Last indexed by Roundhouse
- 2026-10-22 06:50Z
- 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/ev-charging, 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.