Loan amortization schedule API, pay-per-request via x402 on Base (USDC).
What it does
This endpoint at lowpaymentfee.com returns a loan amortization schedule for a specific loan (loan ID 73 in the URL path). It is part of a broader platform offering various pay-per-call APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services — all settled via the x402 protocol on the Base network using USDC.
The endpoint is live and returns a 402 Payment Required challenge, indicating it accepts x402 payments of up to $0.02 per request (maxAmountRequired of 20,000 base units of USDC, which has 6 decimals = $0.02). The payment is made to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using the USDC contract on Base (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). The endpoint accepts POST requests and returns application/json.
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 fields the loan schedule contains or what input parameters the POST body expects. The endpoint path suggests it returns a payment schedule for a pre-existing loan resource (ID 73), but it is unclear whether this is a static resource or whether the POST body can parameterize the schedule calculation. The platform's landing page confirms a flat $0.02/request pricing model with no API keys, no rate limits, and instant access.
Capabilities
Use cases
- —Retrieve a loan amortization schedule showing principal and interest breakdowns per period
- —Integrate loan payment schedule data into financial planning tools
- —Automate loan analysis workflows with per-call micropayments
Fit
Best for
- —Agents or apps needing on-demand loan schedule data without API key management
- —Developers who want to pay per request with crypto (USDC on Base)
- —Quick prototyping of financial tools without subscription commitments
Not for
- —Production use cases requiring documented request/response schemas and SLAs
- —Users who need to create or manage loans (this appears to be read-only for a fixed loan ID)
- —Anyone unable to transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/73/schedule \
-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 OpenAPI schema, no request/response examples, and the endpoint path is hardcoded to a single loan ID with no explanation of input parameters. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or request/response schema provided; input parameters for the POST body are unknown
- —Endpoint path is hardcoded to loan ID 73 — unclear if other loan IDs exist or how loans are created
- —The platform lists many API categories (AI, analytics, finance, etc.) but none have visible documentation, raising questions about maturity
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base, maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/loans/73/schedule
- —Platform pricing is $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/loans/73/schedule