Mortgage data 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/51`. It is part of a broader platform (lowpaymentfee.com) that offers a variety of pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services — all gated via the x402 payment protocol on the Base network using USDC.
The specific endpoint `/api/v1/mortgages/51` accepts POST requests and returns JSON. The x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). This is consistent with the platform's stated flat pricing of $0.02 per request across all endpoints. No API keys are required; payment is handled inline via the X-PAYMENT header.
Documentation on the site is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no substantive content. The mortgage endpoint itself is not listed on the homepage's catalog of available APIs, so its exact response schema and the nature of the data it returns (e.g., whether ID 51 refers to a specific mortgage product, rate quote, or calculation) are unknown. Use with caution until more documentation is available.
Capabilities
Use cases
- —Retrieving mortgage-related data or calculations programmatically
- —Integrating mortgage information into financial dashboards or agent workflows
- —Paying per-request for financial data without API key management
Fit
Best for
- —Developers needing on-demand mortgage data with no subscription
- —AI agents that can settle x402 payments on Base
- —Prototyping financial tools with low per-call costs
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Bulk mortgage data retrieval where per-call pricing would be expensive
- —Anyone unable to pay with USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/mortgages/51 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02/request in USDC on Base), but there is no documentation, no request/response schema, and the mortgage endpoint is not even listed on the provider's homepage. The actual data returned is entirely unknown.
Warnings
- —The /api/v1/mortgages/51 endpoint is not listed in the provider's public API catalog — its purpose and response format are undocumented.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no useful content.
- —No OpenAPI spec, request schema, or response schema is available.
- —The nature of the mortgage data (rate quotes, product info, calculations, etc.) is unknown.
Citations
- —Platform advertises $0.02 per request flat pricing with no API keys, no rate limits, and Base network settlement.https://lowpaymentfee.com
- —x402 challenge shows maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base network.https://lowpaymentfee.com/api/v1/mortgages/51
- —Docs, pricing, API, and README pages all show only 'Connect wallet' with no substantive documentation.https://lowpaymentfee.com/docs