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/charges/322` is listed as "Premium API Access" and returns a 402 challenge requiring payment of 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 lowpaymentfee.com 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.
This particular endpoint (`/api/v1/charges/322`) is labeled "Premium API Access" but the crawled material does not clarify what specific data or functionality it returns beyond the generic label. The docs, pricing, and README pages all rendered only a "Connect wallet" prompt with no additional documentation. Without further detail on the request/response schema, callers should treat this as an under-documented endpoint.
Capabilities
Use cases
- —Programmatic access to premium API functionality paid per-call with USDC on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers or agents wanting zero-signup, pay-per-call API access
- —x402 protocol experimentation on Base mainnet
- —Low-cost micropayment API consumption at $0.02/request
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Use cases requiring free or subscription-based access without crypto wallets
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/322 \
-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 documentation on what the endpoint actually returns, no request/response schema, and the docs/pricing/README pages are all blank beyond a wallet-connect prompt. The "Premium API Access" label is generic and uninformative.
Warnings
- —No documentation available — docs, pricing, and README pages only show 'Connect wallet' with no content.
- —The specific functionality of /api/v1/charges/322 ('Premium API Access') is completely undocumented; it is unclear what data or service it provides.
- —No OpenAPI spec, no request schema, and no response schema available.
- —No examples of successful responses found in crawl material.
Citations
- —Endpoint returns 402 with x402 challenge requiring up to 20,000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/charges/322
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/322
- —Platform advertises $0.02/request, no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com