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 11 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 gated behind the x402 payment protocol on the Base network using USDC.
The endpoint accepts POST requests and returns JSON. Each call costs $0.02 in USDC (20,000 base units with 6 decimals) settled on-chain via the x402 "exact" payment scheme to a specified wallet address. No API keys, rate limits, or upfront commitments are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all rendered only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no description of request parameters (e.g., loan principal, term, interest rate), and no example responses. The endpoint path suggests it serves a pre-configured loan schedule (loan ID 11), but it is unclear whether the POST body allows customization of loan parameters or whether other loan IDs are available. Prospective users should expect to experiment with the endpoint to discover its input/output contract.
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 or budgeting application
- —Agents autonomously fetching loan payment details without API key provisioning
Fit
Best for
- —Developers needing a quick, keyless loan schedule API
- —AI agents that can pay per-call via x402 on Base
- —Prototyping financial tools without subscription commitments
Not for
- —Production use requiring well-documented, stable API contracts
- —Users who need customizable loan parameters (unclear if supported)
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/11/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what loan ID 11 represents or what POST body parameters are accepted. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or input/output schema provided; request parameters and response format are unknown.
- —Endpoint is hardcoded to loan ID 11; unclear if other loan IDs exist or if parameters are customizable.
- —No example responses available to verify functionality.
Citations
- —The endpoint returns HTTP 402 with an x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/loans/11/schedule
- —Price is $0.02 per request (20000 base units of USDC with 6 decimals)https://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/loans/11/schedule