Loan amortization schedule API, pay-per-call via x402 on Base (USDC).
What it does
This endpoint at lowpaymentfee.com returns a loan amortization schedule for a given loan (in this case, loan ID 20). It is part of a broader platform offering various pay-per-request 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 specific endpoint `/api/v1/loans/20/schedule` is a GET request that returns JSON. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0x8335… on Base), which equals $0.02 per request (USDC uses 6 decimals). The platform advertises uniform $0.02/request pricing across all endpoints, with no API keys, no rate limits, and no minimum commitments required. Payment is handled entirely through the x402 protocol's X-PAYMENT header.
While the endpoint is confirmed live (returning a proper 402 challenge), 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 schema, no example responses, and no detailed documentation describing the loan schedule output format or available parameters. The endpoint path suggests it serves a fixed loan ID (20), but it is unclear whether other loan IDs are supported or how loan parameters are configured.
Capabilities
Use cases
- —Retrieving a loan amortization schedule showing principal and interest breakdowns per period
- —Integrating loan payment calculations into financial planning tools
- —Agent-driven financial analysis requiring on-demand loan schedule data
Fit
Best for
- —Developers needing quick loan schedule data without API key signup
- —AI agents that can pay per-call via x402 for financial calculations
- —Applications requiring on-demand amortization tables
Not for
- —Users who need detailed documentation or guaranteed SLA before integrating
- —Bulk loan portfolio analysis requiring thousands of calls (no volume discounts indicated)
- —Custom loan configurations if the endpoint only supports fixed loan IDs
Quick start
curl -X GET https://lowpaymentfee.com/api/v1/loans/20/schedule
# Returns 402 with x402 challenge; attach X-PAYMENT header with USDC payment on Base to access.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no example responses, no documentation beyond a landing page listing, and the endpoint path is hardcoded to loan ID 20 with no explanation of parameters or output format. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all return only 'Connect wallet' with no content
- —No OpenAPI or output schema provided; response format is unknown
- —Endpoint path is hardcoded to loan ID 20; unclear if other loan IDs or parameters are supported
- —The broader platform lists many API categories but this specific loans endpoint is not listed on the homepage
Citations
- —The x402 challenge requires a maximum of 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/loans/20/schedule
- —Platform pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com