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/221 is labeled "Premium API Access" and accepts POST requests with payment via the x402 exact scheme. The x402 challenge indicates a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per call (USDC uses 6 decimals). No API keys or rate limits are advertised; access is granted instantly upon payment.
The broader platform advertises 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 $0.02 per request. However, the specific endpoint probed (/api/v1/payments/221) 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 detailed description of what this particular endpoint actually does or what parameters it accepts.
Capabilities
Use cases
- —Programmatic access to a pay-per-request API without needing API keys or subscriptions
- —Agent-driven API consumption with automatic USDC micropayments on Base
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers exploring x402 payment protocol integrations
- —Agents that need keyless, pay-as-you-go API access on Base
- —Low-cost per-request API consumption without commitments
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Anyone without a Base-network USDC wallet
- —Use cases requiring well-documented request/response schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/221 \
-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 accepts USDC on Base at $0.02/request. However, there is no OpenAPI schema, no request/response examples, and no documentation beyond a generic label. The docs pages are empty (just 'Connect wallet'). It is unclear what this specific endpoint actually returns.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided for this endpoint
- —The endpoint description 'Premium API Access' is generic and does not explain what data or functionality is returned
- —Cannot verify what the endpoint actually does without paying for a request
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/payments/221
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/221
- —All endpoints listed at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com