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 41 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 gated via the x402 payment protocol on the Base network using USDC.
The endpoint accepts POST requests and returns JSON. Payment is handled inline: callers attach an X-PAYMENT header containing a signed USDC payment on Base. The x402 challenge advertises a maximum cost of 20,000 base units of USDC (6 decimals), which equals $0.02 per request. The platform advertises uniform $0.02/request pricing across all its endpoints, with no API keys, no rate limits, and no minimum commitments.
Documentation is extremely sparse. The /docs, /pricing, /api, and /README pages all resolve to a wallet-connect stub with no meaningful content. There is no OpenAPI spec, no request/response schema, and no example payloads available. The specific input parameters for the loan schedule endpoint (e.g., whether the loan ID is variable, what POST body fields are accepted) are unknown from the available material. The endpoint is confirmed live via a valid 402 challenge response.
Capabilities
Use cases
- —Retrieve an amortization schedule for a loan showing principal and interest breakdowns per period
- —Integrate loan schedule data into a financial planning application
- —Automate loan payment calculations without managing API keys or subscriptions
Fit
Best for
- —Agents or apps needing on-demand loan amortization data
- —Developers who want key-free, pay-per-call financial APIs
- —Crypto-native workflows that can settle micropayments in USDC on Base
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume batch processing where per-call pricing may add up
- —Applications requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/41/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-signed-payment-header>"Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI spec, no documentation, no request/response schema, and no examples. The loan schedule endpoint's input parameters and output format are entirely unknown. The docs pages are empty wallet-connect stubs.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README all return empty wallet-connect pages
- —No request body schema or response schema documented for this endpoint
- —The loan ID (41) is hardcoded in the endpoint URL; it is unclear whether other loan IDs are supported or how loans are created
- —The platform lists many endpoint categories but provides no detailed docs for any of them
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/loans/41/schedule
- —Platform-wide pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The /docs, /pricing, /api, and /README pages contain only a 'Connect wallet' stub with no documentation contenthttps://lowpaymentfee.com/docs