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 47 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 via the x402 "exact" payment scheme to the provider's wallet. No API keys, rate limits, or subscriptions are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no description of request parameters (e.g., how to specify loan terms, interest rate, or principal), and no example responses. The specific loan path `/api/v1/loans/47/schedule` is not listed on the homepage's API catalog, so it may be a less-advertised or legacy endpoint. Without request/response schemas, callers will need to experiment or contact the provider to understand the expected input format and output structure.
Capabilities
Use cases
- —Generating an amortization schedule for a loan to see principal and interest breakdowns per period
- —Integrating loan schedule data into a fintech application without managing API keys
- —Agent-driven financial planning that needs on-demand loan calculations
Fit
Best for
- —Developers needing quick, keyless access to loan schedule calculations
- —AI agents that can settle x402 micropayments on Base
- —Pay-as-you-go financial computation without subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume batch loan calculations where per-request pricing adds up
- —Anyone without a Base-network USDC wallet or x402-compatible client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/47/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 ($0.02 USDC on Base), but there is no documentation, no request/response schema, no examples, and the specific loans endpoint isn't even listed on the provider's homepage. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, API, pricing, and README pages all return only a wallet-connect prompt
- —No request body schema or response schema provided; callers must guess or reverse-engineer the expected input
- —The /api/v1/loans/47/schedule path is not listed in the provider's public API catalog, suggesting it may be unlisted or experimental
- —Loan ID 47 is hardcoded in the URL; unclear whether other loan IDs are supported or how loans are created
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/loans/47/schedule
- —The platform advertises $0.02 per request 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/47/schedule