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/40`. It is part of a broader platform (lowpaymentfee.com) that offers dozens of pay-per-request API endpoints 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/40` 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 site's advertised 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 further content. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/mortgages/40` endpoint actually returns (e.g., whether "40" is a mortgage ID, a term length, or something else). The endpoint is live and responding with a valid 402 challenge, but the lack of documentation makes it difficult to know what data to send or expect back.
Capabilities
Use cases
- —Retrieving mortgage-related data or calculations on a per-request basis
- —Integrating mortgage information into agent workflows without API key management
- —Programmatic access to mortgage data settled via crypto micropayments
Fit
Best for
- —Developers or agents needing on-demand mortgage data with no subscription
- —x402-compatible agents that can pay per call in USDC on Base
- —Prototyping financial applications with low per-request costs
Not for
- —Users who need detailed documentation or schema before integrating
- —High-volume mortgage data consumers who need bulk pricing or SLAs
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/mortgages/40 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what the mortgage endpoint accepts or returns. No OpenAPI schema, no examples, and the site's docs pages are empty. The listing is effectively a stub.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet' with no content.
- —No request or response schema for /api/v1/mortgages/40; it is unclear what '40' refers to (mortgage ID, term, etc.).
- —No OpenAPI or machine-readable spec provided.
- —The endpoint's actual functionality and data content cannot be verified from available materials.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/mortgages/40
- —The site advertises $0.02 per request flat pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/mortgages/40