Pay-per-call API platform on Base (USDC) via x402 — $0.02/request, no API keys required.
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/customers/3` is listed as "Premium API Access" and returns a 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 x402 payment header to each request.
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 priced at $0.02 per request.
Note that the specific `/api/v1/customers/3` endpoint's purpose is unclear — it sits under a "customers" path that doesn't appear in the site's public API catalog. No OpenAPI schema, request/response examples, or detailed documentation were found during the crawl (docs, pricing, and API pages all returned only a "Connect wallet" prompt). The endpoint is live and responds with a valid x402 challenge, but the actual data it returns after payment is unknown.
Capabilities
Use cases
- —Accessing premium data endpoints without traditional API key management
- —Making one-off API calls with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
Fit
Best for
- —Developers who want to avoid API key signup and subscription commitments
- —AI agents that can settle x402 payments autonomously on Base
- —Low-volume or sporadic API consumers who prefer per-call pricing
Not for
- —High-volume consumers who need bulk/subscription pricing
- —Users without a Base-network USDC wallet or x402-compatible client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/customers/3 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI schema, no documentation beyond a landing page catalog, no request/response examples, and the specific /api/v1/customers/3 path is not listed in the site's public catalog. The purpose of this particular endpoint is unclear.
Warnings
- —The /api/v1/customers/3 endpoint does not appear in the site's publicly listed API catalog — its actual function is unknown.
- —No OpenAPI spec or detailed documentation was found; docs/pricing/API pages all render only a 'Connect wallet' prompt.
- —No request body schema or response schema is available — callers cannot know what to send or what to expect back.
- —The platform appears to be a demo or early-stage project; treat with caution.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base network.https://lowpaymentfee.com/api/v1/customers/3
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access.https://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/customers/3
- —The site lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com