Pay-per-request API platform on Base via x402 — data, AI, finance, and utility endpoints at $0.02/call.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request 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, paid in USDC on the Base network.
The specific endpoint at `/api/v1/charges/13` is listed as "Premium API Access" and returns a standard x402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base. Payment is made via the x402 exact scheme with no API keys or rate limits required — callers simply attach an X-PAYMENT header to each POST request. The payment address is `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` and the timeout is 300 seconds.
Documentation is extremely sparse. The landing page lists available endpoints and pricing, but the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples. It is unclear what specific data or functionality the `/api/v1/charges/13` endpoint returns, as the description is simply "Premium API Access" with no further detail. The broader platform's individual endpoint capabilities (sentiment analysis, embeddings, etc.) are listed but not documented.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key signup
- —Fetching real-time financial data such as token quotes, exchange rates, and gas estimates on a per-call basis
- —Running data analytics queries and exporting data with instant pay-per-use billing
- —Using utility services like geocoding, validation, and conversion without subscriptions
Fit
Best for
- —Agents and developers who want instant API access without registration or API keys
- —Low-volume or bursty workloads where per-request pricing is more economical than subscriptions
- —Crypto-native applications already operating on the Base network with USDC
Not for
- —High-volume production workloads where per-request costs would accumulate significantly
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/13 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schemas, no documentation beyond a landing page listing, and the specific endpoint's purpose ('Premium API Access') is undefined. The docs, pricing, and README pages are all empty wallet-connect stubs.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The /docs, /pricing, /api, and /README pages all render only 'Connect wallet' with no usable content
- —The specific endpoint /api/v1/charges/13 has no description beyond 'Premium API Access' — its actual functionality is unknown
- —It is unclear whether the listed AI/finance/utility endpoints are fully functional or placeholders
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, on the Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/charges/13 requires up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/charges/13
- —Available endpoint categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —The /docs, /pricing, /api, and /README pages render only 'Connect wallet'https://lowpaymentfee.com/docs