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 46 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. Payment is handled inline via the X-PAYMENT header using the x402 exact-payment scheme. The maximum amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02 USD. The platform advertises a flat $0.02/request pricing model across all endpoints, with no API keys, no rate limits, and no minimum commitments.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples available. The specific input parameters for the loan schedule endpoint (e.g., whether the loan ID is always hardcoded in the path or configurable, what POST body fields are accepted) are unknown. The endpoint is confirmed live via a valid 402 challenge response.
Capabilities
Use cases
- —Retrieving an amortization schedule for a loan showing principal and interest breakdowns per period
- —Integrating loan schedule data into financial planning tools or dashboards
- —Agent-driven financial calculations that need structured loan repayment data
Fit
Best for
- —Developers needing on-demand loan amortization data without API key management
- —AI agents that can pay per-call via x402 for financial computations
- —Prototyping financial apps with zero signup friction
Not for
- —Production systems requiring documented, stable API contracts with SLAs
- —Users who need bulk loan calculations at scale (no documented batch support)
- —Anyone needing detailed API documentation before integration
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/46/schedule \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it exists and accepts payments. However, there is no documentation, no OpenAPI spec, no request/response schema, and no examples. The loan endpoint path has a hardcoded loan ID (46) with no explanation of how to use other IDs or what parameters the POST body accepts. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all return only a wallet-connect prompt with no content
- —No OpenAPI or schema definition; request body parameters and response format are completely unknown
- —The endpoint URL contains a hardcoded loan ID (46); it is unclear whether other loan IDs are supported or how to create/reference loans
- —The platform lists many diverse API categories (AI, analytics, finance, utilities) all at $0.02 — the actual functionality behind each endpoint is unverified
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/loans/46/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 contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/loans/46/schedule