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 81) via a POST request. It is part of a broader platform offering various pay-per-call APIs across data analytics, AI/ML, finance, and utility categories, all settled through the x402 protocol on the Base network using USDC.
The endpoint is live and returns a 402 challenge requesting payment of up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per request. Payment is made to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 on Base. The response MIME type is application/json. No API keys or rate limits are advertised; access is gated purely by the x402 micropayment.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all rendered only a "Connect wallet" prompt with no additional content. There is no OpenAPI schema, no request/response examples, and no description of what fields the loan schedule endpoint accepts or returns. The endpoint path suggests it serves a pre-configured loan (ID 81), but it is unclear whether the POST body allows customization of loan parameters or simply triggers generation of a fixed schedule. Use with caution until more documentation is available.
Capabilities
Use cases
- —Retrieving a loan amortization schedule showing principal and interest breakdowns per period
- —Integrating loan payment data into financial planning tools or dashboards
- —Agent-driven financial calculations requiring on-demand loan schedule generation
Fit
Best for
- —Developers needing a simple pay-per-call loan schedule API without signup
- —AI agents that can settle x402 micropayments on Base for financial data
- —Prototyping financial applications that need amortization data
Not for
- —Production systems requiring well-documented, schema-validated APIs
- —Users who need to compute schedules for arbitrary loan IDs or custom parameters (unclear if supported)
- —Non-crypto users who cannot settle USDC payments on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/81/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the purpose of the specific loan ID 81 is unexplained. Effectively a stub listing.
Warnings
- —No OpenAPI schema or request/response documentation available
- —Docs, API, pricing, and README pages all render only 'Connect wallet' with no useful content
- —Endpoint is hardcoded to loan ID 81; unclear if other loan IDs or custom parameters are supported
- —No information on what fields the POST body accepts or what the response contains
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/loans/81/schedule
- —Platform advertises $0.02 per request, no API keys, no rate limits, Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/loans/81/schedule