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 85 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 to a specified payTo address. The x402 challenge confirms the endpoint is live and uses the "exact" payment scheme with a 300-second timeout. No API keys or rate limits are advertised; access is granted purely through per-request micropayments.
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 documentation, and no explanation of what input parameters the POST body expects or what fields the amortization schedule response contains. The endpoint path suggests it is tied to a specific loan ID (85), but it is unclear whether this is a demo resource or whether other loan IDs are available. Users should expect to experiment with the endpoint to discover its input/output contract.
Capabilities
Use cases
- —Retrieving an amortization schedule for a loan showing principal and interest breakdowns per period
- —Integrating loan payment calculations into financial planning tools
- —Agents autonomously fetching loan schedules without API key provisioning
Fit
Best for
- —Developers needing on-demand loan amortization data via micropayment
- —AI agents that can settle x402 payments on Base for financial data
- —Projects wanting keyless, pay-per-use access to financial calculations
Not for
- —Users who need detailed API documentation before integrating
- —Bulk or high-volume loan schedule generation where per-call fees add up
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/85/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is zero documentation on request parameters or response schema. The /docs and other pages are empty beyond a wallet connect prompt. The endpoint path is hardcoded to loan ID 85 with no explanation of how to use other resources. Effectively a stub listing.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages are all empty
- —No OpenAPI spec or request/response schema provided
- —Endpoint path is hardcoded to loan ID 85; unclear if other loan IDs are supported or how to parameterize
- —The broader platform advertises many API categories but this specific endpoint's functionality is undocumented
Citations
- —Endpoint returns 402 with x402 challenge advertising $0.02 USDC on Base networkhttps://lowpaymentfee.com/api/v1/loans/85/schedule
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/loans/85/schedule