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 19 in this case). 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 its 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 further content. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The endpoint is live (returns a proper 402 challenge), but without documentation it is unclear what request body fields are expected or what the response schedule format looks like. The loan ID (19) is hardcoded in the URL path, suggesting other loan IDs may also be available at similar paths.
Capabilities
Use cases
- —Retrieve a detailed amortization schedule for a given loan
- —Integrate loan payment breakdowns into financial planning tools
- —Programmatic access to loan schedule data without API key management
Fit
Best for
- —Agents needing on-demand loan amortization data with crypto micropayments
- —Developers building financial tools who want keyless API access
- —Applications requiring per-call billing with no subscription overhead
Not for
- —Users who need comprehensive loan origination or underwriting services
- —Applications requiring bulk/batch loan schedule generation at scale (no documented batch endpoint)
- —Users without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/loans/19/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 with clear pricing. However, there is no documentation, no OpenAPI spec, no request/response schema, and no examples. The docs pages are empty stubs. The specific purpose (loan schedule) is only inferable from the URL path. This is effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or request/response schema provided; request body format is unknown
- —Loan ID 19 is hardcoded in the URL; unclear if other loan IDs exist or how to discover them
- —No examples of request or response payloads available anywhere in crawled content
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/loans/19/schedule
- —Platform-wide pricing is $0.02 per request 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/19/schedule