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/transfers/161` is labeled "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
The broader lowpaymentfee.com site lists multiple API categories including 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/request price point. However, the specific endpoint being listed here (`/api/v1/transfers/161`) is described only as "Premium API Access" with no further documentation on what data or functionality it returns.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no description of what the `/transfers/161` endpoint actually does. The endpoint is confirmed live (402 challenge captured), but the lack of documentation makes it difficult to determine its purpose or output format.
Capabilities
Use cases
- —Accessing a pay-per-request API endpoint without needing API keys or subscriptions
- —Making USDC micropayments on Base for individual API calls
- —Programmatic agent-driven API consumption via x402 protocol
Fit
Best for
- —Developers wanting keyless, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation before integrating
- —Applications requiring guaranteed SLAs or support contracts
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/161 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge, but there is zero documentation on what /api/v1/transfers/161 actually returns. No OpenAPI schema, no request/response examples, and all doc pages show only 'Connect wallet'. The purpose of this specific endpoint is unknown.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README all render only 'Connect wallet'
- —The purpose and response format of /api/v1/transfers/161 ('Premium API Access') is completely undocumented
- —No OpenAPI schema or request/response examples provided
- —Cannot verify what data or service this endpoint delivers
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transfers/161
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transfers/161
- —The site lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com