Finance Calculators
Home price you can afford under the 28/36 rule from income, monthly debts, down payment, rate and term.
The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
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.
{
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"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
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"version": "2"
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"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "base",
"mimeType": "application/json",
"resource": "https://finance-calculators.x402tookit.com/mortgage-affordability",
"description": "Home price you can afford under the 28/36 rule from income, monthly debts, down payment, rate and term.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"years": 30,
"down_payment": 60000,
"annual_income": 120000,
"monthly_debts": 500,
"annual_rate_pct": 6.5,
"tax_insurance_monthly": 600
}
},
"output": {
"asOf": "2026-10-11T03:59:14.990Z",
"source": "computed locally",
"maxLoan": 348063.8,
"reasons": [
"28/36 rule: housing costs up to 28% and all debt payments up to 36% of gross monthly income."
],
"summary": "Maximum loan $348,063.80 (payment $2,200.00 for principal and interest), so a price up to $408,063.80 with $60,000.00 down. The housing ratio (28%) is the limit.",
"verdict": "AFFORDABILITY_COMPUTED",
"degraded": false,
"limitedBy": "housing ratio (28%)",
"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": [
"credit score and lender rules",
"closing costs and PMI",
"…2 more"
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"maxPurchasePrice": 408063.8,
"grossMonthlyIncome": 10000,
"maxMonthlyPrincipalInterest": 2200
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"mimeType": "application/json",
"resource": "https://finance-calculators.x402tookit.com/mortgage-affordability",
"description": "Home price you can afford under the 28/36 rule from income, monthly debts, down payment, rate and term.",
"outputSchema": {
"input": {
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"method": "GET",
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"years": 30,
"down_payment": 60000,
"annual_income": 120000,
"monthly_debts": 500,
"annual_rate_pct": 6.5,
"tax_insurance_monthly": 600
}
},
"output": {
"asOf": "2026-10-11T03:59:14.990Z",
"source": "computed locally",
"maxLoan": 348063.8,
"reasons": [
"28/36 rule: housing costs up to 28% and all debt payments up to 36% of gross monthly income."
],
"summary": "Maximum loan $348,063.80 (payment $2,200.00 for principal and interest), so a price up to $408,063.80 with $60,000.00 down. The housing ratio (28%) is the limit.",
"verdict": "AFFORDABILITY_COMPUTED",
"degraded": false,
"limitedBy": "housing ratio (28%)",
"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": [
"credit score and lender rules",
"closing costs and PMI",
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],
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"maxMonthlyPrincipalInterest": 2200
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"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact",
"network": "polygon",
"mimeType": "application/json",
"resource": "https://finance-calculators.x402tookit.com/mortgage-affordability",
"description": "Home price you can afford under the 28/36 rule from income, monthly debts, down payment, rate and term.",
"outputSchema": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"years": 30,
"down_payment": 60000,
"annual_income": 120000,
"monthly_debts": 500,
"annual_rate_pct": 6.5,
"tax_insurance_monthly": 600
}
},
"output": {
"asOf": "2026-10-11T03:59:14.990Z",
"source": "computed locally",
"maxLoan": 348063.8,
"reasons": [
"28/36 rule: housing costs up to 28% and all debt payments up to 36% of gross monthly income."
],
"summary": "Maximum loan $348,063.80 (payment $2,200.00 for principal and interest), so a price up to $408,063.80 with $60,000.00 down. The housing ratio (28%) is the limit.",
"verdict": "AFFORDABILITY_COMPUTED",
"degraded": false,
"limitedBy": "housing ratio (28%)",
"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": [
"credit score and lender rules",
"closing costs and PMI",
"…2 more"
],
"checkPayment": 2200,
"maxPurchasePrice": 408063.8,
"grossMonthlyIncome": 10000,
"maxMonthlyPrincipalInterest": 2200
}
},
"maxAmountRequired": "20000",
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}
],
"x402Version": 1,
"alsoAvailable": {
"llms": "https://finance-calculators.x402tookit.com/llms.txt",
"catalog": "https://finance-calculators.x402tookit.com/catalog",
"message": "Finance Calculators has 9 pay-per-call endpoints (Exact loan, savings, growth, break-even and cash-flow calculations for agents, with no model guesswork.), from $0.02 a call. See the full menu and send your agents our way.",
"openapi": "https://finance-calculators.x402tookit.com/openapi.json",
"related": [
{
"url": "https://finance-calculators.x402tookit.com/loan-payment",
"path": "/loan-payment",
"what": "Loan payment, total interest and amortization preview from principal, annual rate and ter…",
"price": "$0.02"
},
{
"url": "https://finance-calculators.x402tookit.com/npv-irr",
"path": "/npv-irr",
"what": "Net present value and internal rate of return (IRR) for a list of cash flows, with a clea…",
"price": "$0.02"
},
{
"url": "https://finance-calculators.x402tookit.com/pay-convert",
"path": "/pay-convert",
"what": "Convert pay between hourly, weekly, biweekly, monthly and annual for a given hours per we…",
"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.
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
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
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
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
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"extra": {
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"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": {
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"version": "2"
},
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"amount": "20000",
"scheme": "exact",
"network": "eip155:42161",
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]Extensions
{
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"years": 30,
"down_payment": 60000,
"annual_income": 120000,
"monthly_debts": 500,
"annual_rate_pct": 6.5,
"tax_insurance_monthly": 600
}
},
"output": {
"type": "json",
"example": {
"asOf": "2026-10-11T03:59:14.990Z",
"source": "computed locally",
"maxLoan": 348063.8,
"reasons": [
"28/36 rule: housing costs up to 28% and all debt payments up to 36% of gross monthly income."
],
"summary": "Maximum loan $348,063.80 (payment $2,200.00 for principal and interest), so a price up to $408,063.80 with $60,000.00 down. The housing ratio (28%) is the limit.",
"verdict": "AFFORDABILITY_COMPUTED",
"degraded": false,
"limitedBy": "housing ratio (28%)",
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"notChecked": [
"credit score and lender rules",
"closing costs and PMI",
"…2 more"
],
"checkPayment": 2200,
"maxPurchasePrice": 408063.8,
"grossMonthlyIncome": 10000,
"maxMonthlyPrincipalInterest": 2200
}
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
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"properties": {
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"required": [
"type",
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"const": "http"
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"method": {
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"GET"
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"type": "string"
},
"queryParams": {
"type": "object",
"required": [
"annual_income",
"annual_rate_pct"
],
"properties": {
"years": {
"type": "integer",
"description": "Term in years, default 30"
},
"down_payment": {
"type": "number",
"description": "Cash down payment, default 0"
},
"annual_income": {
"type": "number",
"description": "Gross annual household income"
},
"monthly_debts": {
"type": "number",
"description": "Other monthly debt payments, default 0"
},
"annual_rate_pct": {
"type": "number",
"description": "Mortgage rate in percent"
},
"tax_insurance_monthly": {
"type": "number",
"description": "Property tax plus insurance per month, default 0"
}
}
}
},
"additionalProperties": false
},
"output": {
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"properties": {
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]
},
"notChecked": {
"type": [
"array",
"null"
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}
},
"checkPayment": {
"type": [
"null",
"number"
]
},
"maxPurchasePrice": {
"type": [
"null",
"number"
]
},
"grossMonthlyIncome": {
"type": [
"null",
"number"
]
},
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"number"
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}
}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)
- 2026-10-20 23:15Z
- 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 Finance 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=Finance%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://finance-calculators.x402tookit.com/mortgage-affordability, 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.