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 13 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 settled via the x402 protocol on the Base network using USDC.
The endpoint is live and returns a 402 challenge requesting payment of up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per request. Payment is made via the x402 "exact" scheme to the specified wallet address. The response MIME type is application/json. The endpoint accepts POST requests and is marked as discoverable.
Documentation beyond the landing page is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request body schema, and no example responses available. The specific input parameters for generating or retrieving a loan schedule (e.g., principal, rate, term) are unknown. The endpoint path suggests it retrieves a pre-existing schedule for loan ID 13 rather than generating one dynamically, but this cannot be confirmed from available material.
Capabilities
Use cases
- —Retrieving a loan amortization schedule showing payment breakdowns over time
- —Integrating loan schedule data into financial planning tools
- —Agent-driven financial analysis requiring structured loan payment data
Fit
Best for
- —Developers needing on-demand loan schedule data without API key management
- —AI agents that can settle micropayments via x402 on Base
- —Applications requiring pay-per-use financial calculation endpoints
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume batch processing where per-request pricing may add up
- —Custom loan configurations if the endpoint only serves a fixed loan ID
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/13/schedule \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it exists and accepts payments. However, there is no OpenAPI spec, no request/response schema, no documentation, and no examples. The endpoint path is specific to loan ID 13 with no indication of how to use other loan IDs or what parameters are accepted. Effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only a wallet connect prompt
- —No request body schema or example responses available; input parameters are unknown
- —Endpoint path is hardcoded to loan ID 13 — unclear if other loan IDs are supported or how loans are created
- —The platform lists many API categories on its landing page but this specific loans endpoint is not listed among them
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/loans/13/schedule
- —The platform advertises $0.02 per 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/13/schedule