Loan amortization schedule API, pay-per-call at $0.02 via USDC on Base.
What it does
This endpoint at lowpaymentfee.com returns a loan amortization schedule for a specific loan (loan ID 5 in the URL path). It is part of a broader platform offering dozens of pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services. All endpoints use the x402 payment protocol, settling in USDC on the Base network.
The specific endpoint `/api/v1/loans/5/schedule` accepts POST requests and returns JSON. Based on the x402 challenge, the maximum amount required per call is 20,000 base units of USDC (0x8335… on Base), which equals $0.02 USD (USDC uses 6 decimals). The platform advertises uniform $0.02/request pricing across all its APIs with no API keys, no rate limits, and no minimum commitments.
Documentation 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 parameters the loan schedule endpoint expects or what fields it returns. The endpoint is live (returns a proper 402 challenge), but without documentation it is difficult to know what request body to send or what output to expect.
Capabilities
Use cases
- —Generating an amortization schedule for a loan to see principal and interest breakdowns per period
- —Integrating loan schedule data into a financial planning application
- —Agents autonomously fetching loan repayment details as part of a financial workflow
Fit
Best for
- —Developers needing on-demand loan amortization data without API key management
- —AI agents that can pay per request via x402/USDC on Base
- —Applications requiring simple, low-cost financial calculations
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume batch processing where $0.02 per call adds up significantly
- —Production systems requiring SLA guarantees or support contracts
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/5/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no documentation, no OpenAPI schema, no request/response examples, and the docs pages are empty. The loan schedule endpoint's expected input and output are entirely unknown.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema describing request parameters or response format for the loan schedule endpoint
- —The endpoint path is hardcoded to loan ID 5; it is unclear whether other loan IDs are supported or how loans are created
- —Cannot verify what the endpoint actually returns without making a paid request
Citations
- —The endpoint returns HTTP 402 with an x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/loans/5/schedule
- —The platform advertises $0.02/request 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/loans/5/schedule