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 43 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 standard x402 402 challenge when called without payment. The price is $0.02 per request (20,000 base units of USDC with 6 decimals). Payment is made via the x402 "exact" scheme to the specified wallet address on Base. The endpoint accepts POST requests and returns application/json. No API keys or rate limits are advertised; access is gated purely by micropayment.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all rendered only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no description of request parameters, and no example responses. The specific endpoint path suggests it returns a payment schedule for a pre-existing loan resource (ID 43), but it is unclear whether callers can specify different loan IDs, pass loan parameters in the POST body, or if this is a fixed demo resource. The platform's landing page lists many endpoint categories but this particular loans/schedule endpoint is not among them, raising questions about its discoverability and documentation status.
Capabilities
Use cases
- —Retrieving a loan amortization schedule showing principal and interest breakdowns per period
- —Integrating loan payment calculations into financial planning tools
- —Agent-driven financial analysis requiring on-demand loan schedule data
Fit
Best for
- —Developers needing a simple pay-per-call loan schedule endpoint without API key management
- —AI agents that can settle x402 micropayments on Base for financial data
- —Prototyping financial applications with low-cost per-request pricing
Not for
- —Production use requiring detailed API documentation and SLAs
- —Bulk loan portfolio analysis where per-request costs would accumulate significantly
- —Users who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/43/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no request/response examples, no documentation beyond a wallet-connect prompt, and the specific loans/schedule endpoint is not listed on the provider's own landing page. The purpose and parameters of this endpoint are largely inferred from the URL path alone.
Warnings
- —No API documentation available — docs, pricing, and README pages all show only 'Connect wallet'
- —This specific endpoint (/api/v1/loans/43/schedule) is not listed among the provider's advertised APIs on the landing page
- —Request body schema and response format are completely unknown
- —It is unclear whether loan ID 43 is a fixed resource or if other IDs are supported
- —No OpenAPI or schema definition provided
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/loans/43/schedule
- —Platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/loans/43/schedule