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 `/api/v1/transfers/181` is listed as "Premium API Access" and returns a standard x402 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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 uniformly priced at $0.02 per request.
This particular endpoint (`/api/v1/transfers/181`) is labeled "Premium API Access" but its actual functionality is unclear — the description is generic and no OpenAPI schema, request/response examples, or detailed documentation were found. The docs, pricing, and API pages all returned only a "Connect wallet" prompt with no substantive content. Callers should be aware that the endpoint's concrete behavior is undocumented beyond its title.
Capabilities
Use cases
- —Programmatic access to a premium API endpoint with per-call USDC micropayments
- —Agent-driven workflows that need keyless, on-demand API access settled on Base
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC on Base for per-call API access
- —Use cases requiring no-signup, no-API-key access
Not for
- —Users who need detailed documentation or guaranteed SLAs before calling
- —Applications requiring known, well-documented response schemas
- —Non-crypto callers who cannot produce x402 payment headers
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/181 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no meaningful documentation — the docs pages all show only 'Connect wallet'. The actual functionality behind 'Premium API Access' at /api/v1/transfers/181 is entirely undocumented.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The endpoint name 'Premium API Access' is generic; actual functionality is unknown
- —All documentation pages (docs, pricing, API, README) returned only 'Connect wallet' with no content
- —No request body schema or response format documented anywhere
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/transfers/181
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com