Mortgage data endpoint on Base, pay-per-request via x402 with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to mortgage-related data at `/api/v1/mortgages/21`. It is part of a broader platform (lowpaymentfee.com) that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance, crypto, and utility services — all gated via the x402 payment protocol on the Base network.
The specific endpoint `/api/v1/mortgages/21` accepts POST requests and returns JSON. Payment is settled in USDC on Base (contract `0x8335…2913`), with a maximum amount of 20,000 base units. Since USDC uses 6 decimals, this translates to $0.02 per request, consistent with the platform's uniform $0.02/request pricing across all endpoints. No API keys are required; access is granted by including a valid X-PAYMENT header with each call.
The platform advertises no rate limits, no minimums, and instant access. However, documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no description of what mortgage data is actually returned (e.g., rates, amortization schedules, property data). The endpoint path suggests it may return data for a specific mortgage record (ID 21), but this is speculative. The x402 challenge is live and well-formed.
Capabilities
Use cases
- —Retrieving mortgage-related data programmatically without API key registration
- —Integrating mortgage information into agent workflows with per-call crypto payments
- —Accessing financial data via x402 protocol on Base network
Fit
Best for
- —Developers wanting keyless, pay-per-call mortgage data access
- —AI agents that can settle x402 payments in USDC on Base
- —Prototyping financial applications with low per-request costs
Not for
- —Users needing detailed documentation or guaranteed SLAs before integration
- —Bulk mortgage data retrieval at scale (no documented batch endpoints)
- —Users who cannot transact in USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/mortgages/21 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and pricing is clear ($0.02 USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and no description of what data the mortgage endpoint actually returns. Effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema describing request parameters or response format for /api/v1/mortgages/21
- —Unknown what mortgage data is returned — the endpoint path and description are generic ('Premium API Access')
- —The endpoint path '/api/v1/mortgages/21' is not listed on the provider's homepage among available APIs, raising questions about its status
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/mortgages/21
- —Platform-wide pricing is $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/mortgages/21