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 15 in the URL path). It is part of a broader platform offering dozens of 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 per request is $0.02 (20,000 base units of USDC with 6 decimals). Payment is made via the x402 "exact" scheme to a specified wallet address on Base. No API keys, rate limits, or subscriptions 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 render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what input parameters the POST body expects or what the schedule response looks like. The endpoint path suggests it returns an amortization schedule for loan ID 15, but it is unclear whether the loan ID is variable, what fields the schedule contains, or what POST body (if any) is required.
Capabilities
Use cases
- —Retrieve a loan amortization schedule showing principal and interest breakdowns per period
- —Integrate loan schedule data into a financial planning application
- —Automate loan analysis workflows with per-call payment and no subscription
Fit
Best for
- —Agents or apps needing on-demand loan schedule data without API key management
- —Developers building financial tools who prefer pay-per-use pricing
- —Crypto-native applications that can settle payments on Base L2
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume batch processing where per-call pricing may add up
- —Applications requiring authenticated sessions or complex query parameters (no docs available to confirm support)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/15/schedule \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"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, and all documentation pages render only a wallet-connect prompt. The specific purpose of this endpoint (loan 15 schedule) is inferred solely from the URL path. This is effectively a stub listing.
Warnings
- —No API documentation available — all doc pages render only 'Connect wallet' with no content
- —No OpenAPI or JSON schema describing request body or response format
- —Endpoint path is hardcoded to loan ID 15; unclear if other loan IDs are supported or how to parameterize
- —No request or response examples available from any source
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/loans/15/schedule
- —Platform pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/loans/15/schedule