Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/payments/220` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, documentation beyond the landing page is essentially empty (all doc/pricing/API pages just show "Connect wallet"), so the actual request/response schemas for individual endpoints are unknown. Without documentation on what parameters each endpoint accepts or what data it returns, integration requires experimentation.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification) without API key management
- —Fetching real-time crypto token quotes or gas estimates via pay-per-call
- —Geocoding or data validation as a utility service with no subscription commitment
- —Exporting analytics data or generating insights on a per-request billing model
Fit
Best for
- —AI agents that need keyless, pay-per-call access to diverse utility endpoints
- —Developers wanting to avoid subscription commitments for low-volume API usage
- —x402-compatible wallets and agents on the Base network
Not for
- —High-volume production workloads where per-request pricing becomes expensive
- —Users who need detailed API documentation and guaranteed SLAs before integrating
- —Non-crypto users without Base network USDC wallets
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/220 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, all documentation pages are empty (just 'Connect wallet'), there is no OpenAPI spec, no request/response schema, and no examples. The 'Premium API Access' label is generic and doesn't describe what the endpoint actually does. This is effectively a stub listing.
Warnings
- —All documentation pages (/docs, /pricing, /api, /README) are empty — only showing 'Connect wallet'
- —No request or response schema available for any endpoint
- —The 'Premium API Access' endpoint at /api/v1/payments/220 has no description of what it actually returns
- —Cannot verify that the advertised AI/ML, finance, or utility endpoints actually function as described
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/payments/220
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com