Pay-per-call premium API on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints settled over the x402 protocol on the Base network using USDC. The specific endpoint `/api/endpoint-38` is labeled "Premium API Access" and accepts POST requests. Payment is 0.02 USDC per call (maxAmountRequired of 20,000 base units with 6-decimal USDC). No API keys, rate limits, or upfront commitments are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform advertises 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 listed endpoints share the same $0.02/request pricing.
However, the specific endpoint `/api/endpoint-38` does not correspond to any of the named endpoints on the site's landing page. There is no documentation, request/response schema, or example available for this particular path. The docs, pricing, and API pages all returned only a "Connect wallet" prompt with no substantive content. Without knowing what this endpoint actually does, callers should treat it as an opaque premium access point until further documentation is published.
Capabilities
Use cases
- —Programmatic access to a premium API endpoint without needing API key registration
- —Agent-driven workflows that settle per-call costs in USDC on Base
- —Testing x402 payment flows against a low-cost live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol integration
- —AI agents that need keyless, pay-as-you-go API access
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or guaranteed SLAs before calling
- —Anyone without a Base-network USDC wallet or x402-compatible client
- —High-throughput production workloads requiring well-documented schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-38 \
-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 zero documentation on what /api/endpoint-38 actually does — no input schema, no output schema, no examples. The docs/pricing/API pages are all empty beyond a wallet-connect prompt. The endpoint path doesn't match any named service on the landing page. This is effectively a stub listing.
Warnings
- —Endpoint path /api/endpoint-38 does not match any documented endpoint on the provider's landing page — its actual functionality is unknown.
- —All documentation pages (docs, pricing, API, README) returned only a 'Connect wallet' prompt with no substantive content.
- —No request or response schema is available; callers cannot know what to send or what to expect back.
- —Provider site appears to be a generic x402 demo or template rather than a production service.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/endpoint-38
- —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
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/endpoint-38
- —The site lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com