Loan amortization schedule API, pay-per-call at $0.02 via USDC on Base.
What it does
This x402-enabled endpoint at lowpaymentfee.com returns a loan payment schedule for a specific loan (loan ID 84 in this URL pattern). It is part of a broader platform offering various pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, infrastructure utilities, and more — all priced at $0.02 per request with no API keys, no rate limits, and no commitments required.
The endpoint accepts POST requests and is gated by the x402 payment protocol. Callers must include an X-PAYMENT header containing a valid payment proof. The payment settles in USDC on the Base network, with a maximum amount of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The response MIME type is application/json, and the x402 challenge timeout is 300 seconds.
Documentation on the site is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional content. There is no OpenAPI schema, no request/response examples, and no description of what fields the loan schedule endpoint expects or returns. The endpoint path suggests it retrieves or generates an amortization schedule for loan ID 84, but the exact input parameters and output structure are unknown.
Capabilities
Use cases
- —Retrieve a loan amortization schedule showing principal and interest breakdowns per period
- —Integrate loan schedule data into financial planning or lending applications
- —Automate loan payment calculations without maintaining a subscription or API key
Fit
Best for
- —Developers needing on-demand loan schedule calculations without API key management
- —Agents that can pay per-call via x402 USDC on Base
- —Low-volume or sporadic loan schedule lookups where $0.02/request is cost-effective
Not for
- —High-volume batch loan calculations where per-request pricing adds up quickly
- —Users who need detailed API documentation or guaranteed SLA before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/84/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it exists and is gated. However, there is no OpenAPI schema, no request/response examples, and the docs pages are empty stubs. The specific loan schedule endpoint's input parameters and output format are entirely unknown, making integration speculative.
Warnings
- —No API documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or JSON schema describing request parameters or response structure for the loan schedule endpoint.
- —The endpoint path is hardcoded to loan ID 84; it is unclear whether other loan IDs are supported or how to parameterize requests.
- —The platform lists many API categories on its homepage but provides no verifiable documentation for any of them.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/loans/84/schedule
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/loans/84/schedule