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/330` is labeled "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting up to 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 required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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 here (`/api/v1/payments/330`) is only described 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 `/payments/330` endpoint actually does. The platform's concept is clear — low-fee, keyless, per-call APIs settled in USDC on Base — but the lack of documentation for this specific endpoint makes it difficult to know what you're paying for.
Capabilities
Use cases
- —Programmatic access to premium API functionality paid per-call in USDC on Base
- —Agent-driven workflows that need keyless, instant API access without subscriptions
- —Demonstrating x402 payment protocol integration for pay-per-use services
Fit
Best for
- —Developers wanting to test x402 protocol integrations
- —Agents that can settle USDC payments on Base L2
- —Users who prefer pay-per-call pricing with no commitments or API keys
Not for
- —Users who need detailed API documentation or guaranteed SLAs before paying
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/330 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is zero documentation on what this specific endpoint returns. No OpenAPI schema, no request/response examples, and all doc pages render only 'Connect wallet'. The endpoint's purpose beyond 'Premium API Access' is unknown.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format for /api/v1/payments/330
- —The label 'Premium API Access' is generic and does not describe what data or functionality is provided
- —Cannot verify what the endpoint actually returns without making a paid request
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/payments/330
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com