Mortgage data API endpoint on Base, pay-per-call via x402 with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to mortgage-related data at the path `/api/v1/mortgages/9`. It is part of a broader platform offering dozens of pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services. All endpoints use the x402 payment protocol, settling in USDC on the Base network with no API keys, no rate limits, and no subscriptions required.
The specific `/api/v1/mortgages/9` endpoint accepts POST requests and returns JSON. Based on the x402 challenge, the maximum cost per request is 20,000 base units of USDC (6 decimals), which equals $0.02 USD. The platform advertises a flat $0.02/request pricing across all its endpoints. Payment is made via the x402 `exact` scheme to the specified payee address on Base.
Documentation is extremely sparse — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no explanation of what data the mortgages endpoint actually returns or what parameters it accepts. The endpoint is live (returns a valid 402 challenge), but without documentation it is unclear what mortgage data is served or what the resource ID `9` represents.
Capabilities
Use cases
- —Retrieving mortgage-related data on a per-request basis without subscriptions
- —Integrating mortgage information into agent workflows that can settle payments via x402
- —Programmatic access to mortgage records for financial analysis
Fit
Best for
- —Agents or apps that need on-demand mortgage data with crypto micropayments
- —Developers experimenting with x402 pay-per-call APIs
- —Use cases where no API key management is desired
Not for
- —Production systems requiring well-documented request/response schemas
- —Bulk mortgage data retrieval at scale (pay-per-request model may be costly)
- —Users who cannot pay with USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/mortgages/9 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it exists and accepts payments. However, there is zero documentation on what the mortgages endpoint does, what parameters it accepts, or what it returns. No OpenAPI spec, no examples, and the docs pages are empty. This is effectively a stub listing.
Warnings
- —No documentation available for the /api/v1/mortgages/9 endpoint — request parameters and response format are unknown
- —Docs, pricing, API, and README pages all render only 'Connect wallet' with no technical content
- —The resource path '/mortgages/9' suggests a specific record but there is no explanation of what ID 9 represents or how to discover other IDs
- —No OpenAPI or schema specification provided
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/mortgages/9
- —Platform advertises $0.02/request flat pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/mortgages/9