Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
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/171 is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an X-PAYMENT header with a valid x402 payment proof to authenticate each request.
The broader 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 listed at the same $0.02 per request price point.
However, the specific endpoint /api/v1/payments/171 has no detailed documentation about what it returns or what input it expects beyond a POST request. The docs, pricing, and API pages on the site all render only a "Connect wallet" prompt with no further content. Without schema details or example responses, it is unclear what data or functionality this particular endpoint provides.
Capabilities
Use cases
- —Programmatic access to premium API endpoints without subscription or API key management
- —Agent-driven workflows that need on-demand paid API calls settled in USDC on Base
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —AI agents that need keyless, pay-per-use API access
- —Users who prefer crypto micropayments over traditional billing
Not for
- —Users who need detailed API documentation and response schemas before integrating
- —High-volume use cases where per-request pricing may add up versus flat-rate plans
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/171 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no documentation on what this specific endpoint does, no input/output schema, no example requests or responses, and the site's docs/pricing/API pages are empty beyond a wallet connect prompt. The listing title 'Premium API Access' is generic and uninformative.
Warnings
- —No documentation available for /api/v1/payments/171 — unclear what data or service it provides
- —All non-homepage pages (docs, pricing, API, README) render only 'Connect wallet' with no content
- —No OpenAPI spec, no input schema, no output schema, and no example responses available
- —The endpoint name 'Premium API Access' is generic and does not describe functionality
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/payments/171
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, instant access, and Base network settlementhttps://lowpaymentfee.com