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 accessible via the x402 payment protocol on the Base network. This specific endpoint (`/api/endpoint-90`) is labeled "Premium API Access" and accepts USDC payments on Base. The x402 challenge confirms the endpoint is live and charges a maximum of 20,000 base units of USDC (i.e., $0.02 per request, since USDC uses 6 decimals). Payment is settled on-chain to the specified wallet address, and no API keys or subscriptions are needed.
The broader lowpaymentfee.com platform advertises endpoints across several 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-90` does not map to any of the named endpoints on the site's landing page, so its exact functionality is unclear.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional content. There is no OpenAPI schema, no request/response examples, and no description of what `/api/endpoint-90` actually returns. The endpoint responds to POST requests and declares `application/json` as its MIME type, but input parameters and output format are unknown.
Capabilities
Use cases
- —Accessing a pay-per-call API endpoint without needing API keys or subscriptions
- —Making on-chain micropayments for API access using USDC on Base
- —Programmatic agent-driven API consumption via x402 protocol
Fit
Best for
- —Developers wanting zero-signup API access with crypto micropayments
- —AI agents that can settle x402 payment challenges autonomously
- —Users who prefer pay-as-you-go pricing without rate limits
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Anyone without a Base-compatible USDC wallet
- —Use cases requiring well-documented input/output schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-90 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the specific function of /api/endpoint-90 is unknown. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —The endpoint path /api/endpoint-90 does not correspond to any named endpoint on the provider's landing page — its actual functionality is unknown.
- —Documentation pages (/docs, /api, /pricing, /README) contain no useful content beyond a 'Connect wallet' prompt.
- —No OpenAPI schema or input/output examples are available; request format must be guessed.
- —The provider site lists many endpoint categories but offers no technical detail on any of them.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (USD Coin) on Base network, equating to $0.02 per request.https://lowpaymentfee.com/api/endpoint-90
- —The landing page lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all priced at $0.02/request.https://lowpaymentfee.com
- —The site advertises no API keys, no rate limits, instant access, and Base network settlement.https://lowpaymentfee.com
- —Documentation, API, pricing, and README pages render only a 'Connect wallet' prompt with no additional content.https://lowpaymentfee.com/docs