Mortgage data endpoint on Base, paid per-call with USDC via x402.
What it does
This endpoint at lowpaymentfee.com provides access to mortgage-related data behind an x402 paywall. The specific resource `/api/v1/mortgages/4` is a POST endpoint that returns JSON and costs $0.02 per request, settled in USDC on the Base network. The x402 challenge confirms the endpoint is live and accepting payments.
The broader lowpaymentfee.com platform advertises a wide catalog of pay-per-call APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services — all priced at $0.02 per request with no API keys, no rate limits, and no commitments. However, the specific `/api/v1/mortgages/4` endpoint is not listed on the site's landing page among the advertised categories, so its exact response schema and data content are unclear. No OpenAPI spec, detailed documentation, or example responses were found during the crawl; the docs, pricing, and README pages all returned only a "Connect wallet" prompt with no substantive content.
Payment is made via the x402 protocol using USDC (contract `0x8335...2913`) on Base. The `maxAmountRequired` of 20000 base units equals $0.02 (USDC uses 6 decimals). The endpoint accepts POST requests and is marked as discoverable.
Capabilities
Use cases
- —Retrieving mortgage-related data on demand without subscription
- —Integrating mortgage information into agent workflows via x402 micropayments
- —Accessing financial data endpoints with crypto-native payment rails
Fit
Best for
- —Agents or apps needing on-demand mortgage data with no signup
- —Developers experimenting with x402 pay-per-call protocols
- —Crypto-native workflows that settle in USDC on Base
Not for
- —Users needing well-documented, schema-specified mortgage APIs
- —Bulk mortgage data retrieval (no documented batch endpoint)
- —Fiat-only payment environments without x402 support
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/mortgages/4 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is no OpenAPI spec, no documentation, no example request/response, and the specific mortgages/4 endpoint is not even listed on the provider's own landing page. The response schema is entirely unknown.
Warnings
- —The /api/v1/mortgages/4 endpoint is not listed among the provider's advertised APIs on the landing page — its data content and schema are unknown.
- —No OpenAPI spec or documentation found; docs/pricing/README pages returned only a wallet-connect prompt.
- —Response format and fields are completely undocumented; callers cannot predict what they will receive.
Citations
- —The x402 challenge returns 402 with maxAmountRequired of 20000 base units in USDC on Base network.https://lowpaymentfee.com/api/v1/mortgages/4
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base.https://lowpaymentfee.com/api/v1/mortgages/4
- —The platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant access.https://lowpaymentfee.com
- —The landing page lists APIs in categories: Data & Analytics, AI & ML, Finance & Web3, Infrastructure — but no mortgages category.https://lowpaymentfee.com