Loan amortization schedule endpoint, pay-per-request via x402 on Base (USDC).
What it does
This x402-enabled endpoint at lowpaymentfee.com returns a loan amortization schedule for loan ID 63. It is part of a broader platform offering pay-per-call APIs across data analytics, AI/ML, finance, and utility categories, all settled on the Base network using USDC. The endpoint accepts POST requests and returns JSON.
The x402 challenge confirms the endpoint is live and charges a maximum of $0.02 per request (20,000 base units of USDC with 6 decimals = $0.02). Payment is made via the x402 exact scheme to the specified wallet address on Base. No API keys, rate limits, or subscriptions are required — each call is individually settled on-chain.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all rendered only a "Connect wallet" prompt with no further content. The specific input schema for the POST body (e.g., what loan parameters to supply) is not documented anywhere in the available material. The endpoint path suggests it returns a schedule for a fixed loan (ID 63), but it is unclear whether the caller can customize parameters. Use with caution until better documentation is available.
Capabilities
Use cases
- —Retrieve a loan amortization schedule showing principal and interest breakdowns per period
- —Integrate pay-per-call loan schedule data into financial planning tools
- —Programmatic access to loan payment schedules without API key management
Fit
Best for
- —Agents or apps needing on-demand loan schedule data with no subscription
- —Developers experimenting with x402 micropayment-gated APIs
- —Quick one-off amortization lookups settled via USDC on Base
Not for
- —Bulk or high-volume loan analytics requiring batch pricing
- —Users who need detailed API documentation before integrating
- —Applications requiring customizable loan parameters (unclear if supported)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/63/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear at $0.02/request in USDC on Base. However, there is no OpenAPI schema, no documented input/output format, no examples, and all documentation pages returned only a wallet-connect prompt. The specific purpose of this endpoint (loan 63 schedule) is inferred solely from the URL path.
Warnings
- —No API documentation available — all doc pages render only 'Connect wallet'
- —Input schema for the POST body is completely unknown
- —The endpoint path is hardcoded to loan ID 63; unclear if other loan IDs or custom parameters are supported
- —The endpoint is not listed on the provider's homepage among their advertised APIs
Citations
- —The endpoint returns a 402 challenge with x402Version 1, accepting USDC on Base with maxAmountRequired of 20000 (=$0.02)https://lowpaymentfee.com/api/v1/loans/63/schedule
- —The 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 is the canonical USDC contract on Basehttps://lowpaymentfee.com/api/v1/loans/63/schedule