Loan amortization schedule API on Base, pay $0.02 per request in USDC via x402.
What it does
This endpoint at lowpaymentfee.com returns a loan amortization schedule for a specific loan (loan ID 12 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 priced at $0.02 per request and settled via the x402 protocol using USDC on the Base network.
The endpoint accepts POST requests and returns JSON. Payment is handled inline: callers attach an X-PAYMENT header containing an x402 payment proof for 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) to the payTo address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3. No API keys, accounts, or rate limits are advertised — access is purely payment-gated.
Documentation is extremely sparse. The crawled /docs, /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no substantive 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 loan terms, principal, or rate are passed in the POST body or are pre-configured for loan ID 12) are unknown. The endpoint is confirmed live via a valid 402 challenge response.
Capabilities
Use cases
- —Retrieve a loan amortization schedule showing principal and interest breakdowns per period
- —Integrate pay-per-call loan calculations into a financial planning agent
- —Programmatically fetch repayment schedules without API key management
Fit
Best for
- —Agents needing on-demand loan schedule data with no signup
- —Developers building financial tools who prefer crypto micropayments
- —Automated workflows requiring amortization tables
Not for
- —Users who need detailed API documentation before integrating
- —Applications requiring custom loan parameters (unclear if supported)
- —High-volume batch processing where per-request pricing may add up
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/12/schedule \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, but documentation is essentially nonexistent — no OpenAPI spec, no request/response schemas, no examples. The loan schedule endpoint's input parameters and output format are completely unknown. The listing is effectively a stub.
Warnings
- —No API documentation available; /docs, /api, /pricing, and /README pages all return only a wallet-connect prompt
- —No OpenAPI or schema definition found for request or response payloads
- —Unknown what input parameters the POST body expects or what the loan schedule response looks like
- —The URL is hardcoded to loan ID 12; unclear if other loan IDs are supported or how loans are created
Citations
- —Endpoint returns 402 with x402 challenge requiring 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/loans/12/schedule
- —Platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/loans/12/schedule