Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint at `/api/v1/payments/141` is listed as "Premium API Access" and returns a live 402 challenge requiring up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform offers endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request and settle in USDC on Base.
Note that this specific endpoint (`/api/v1/payments/141`) is labeled generically as "Premium API Access" and does not appear in the site's public API listing. Its actual functionality beyond the payment gate is unclear — there is no OpenAPI schema, no documented request/response format, and the crawled docs pages returned only a wallet-connect prompt with no substantive content. Treat this endpoint with caution until more documentation surfaces.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic access to gated endpoints without subscription or signup
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle x402 payments autonomously
- —Users already holding USDC on the Base network
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Anyone without USDC on Base or an x402-compatible payment client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/141 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documented request/response format, and the endpoint path (/api/v1/payments/141) doesn't match any publicly listed API on the site. Docs pages returned only wallet-connect stubs with no content. Functionality is essentially unknown.
Warnings
- —Endpoint /api/v1/payments/141 is not listed among the site's publicly documented APIs — its actual functionality is unknown.
- —No OpenAPI spec, request schema, or response schema is available.
- —All documentation pages (/docs, /api, /pricing, /README) returned only a 'Connect wallet' stub with no substantive content.
- —The generic label 'Premium API Access' provides no indication of what data or service is returned after payment.
Citations
- —The endpoint returns a live 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/141
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/141
- —Platform advertises $0.02/request, no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —Site lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com