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 86) via a POST request. 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 through the x402 protocol on the Base network using USDC.
The x402 challenge confirms the endpoint is live and accepts payments of up to $0.02 per request (20,000 base units of USDC with 6 decimals = $0.02). No API keys or rate limits are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof. The response MIME type is application/json.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all rendered only a "Connect wallet" prompt with no additional 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 loan 86, but the request body schema and response structure are entirely unknown. The platform advertises uniform $0.02 pricing across all endpoints, no minimums, and no commitments.
Capabilities
Use cases
- —Retrieving a loan amortization schedule showing principal and interest breakdowns per period
- —Integrating loan payment schedule data into financial planning tools
- —Agent-driven loan analysis workflows that need structured repayment data
Fit
Best for
- —Developers needing quick, keyless access to loan schedule data
- —AI agents that can pay per-call via x402 without pre-registration
- —Prototyping financial applications with minimal setup
Not for
- —Production systems requiring documented, stable API contracts with SLAs
- —Use cases needing custom loan parameters (the endpoint is hardcoded to loan ID 86)
- —Users who cannot transact on the Base network with USDC
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/86/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear at $0.02/request in USDC on Base. However, there is no OpenAPI schema, no request/response documentation, no examples, and the endpoint is scoped to a single hardcoded loan ID with no explanation of what parameters it accepts. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and README pages all render only a wallet-connect prompt with no content.
- —No request body schema or response schema documented; callers must guess at the expected input.
- —Endpoint is hardcoded to loan ID 86 — unclear if other loan IDs are supported or how loans are created.
- —No OpenAPI specification or ai-plugin manifest found.
Citations
- —The endpoint returns HTTP 402 with an x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/loans/86/schedule
- —maxAmountRequired is 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), equaling $0.02https://lowpaymentfee.com/api/v1/loans/86/schedule
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com