Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, rate limits, or subscriptions are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/charges/188` is listed as "Premium API Access" and requires a maximum of 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises categories including: 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 (geocoding, validation, conversion, generation). Each of these is a separate endpoint, all at the same $0.02 price point.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. The x402 challenge is live and well-formed, confirming the endpoint accepts POST requests and pays out to a specified Ethereum address on Base. However, without documentation it is unclear what request body this particular endpoint expects or what response it returns.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data and crypto quotes with per-request USDC micropayments
- —Using utility services like geocoding, validation, and data conversion on a pay-as-you-go basis
- —Building agent workflows that pay for API calls programmatically via x402
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents that can settle payments on Base via x402
- —Projects needing low-cost micropayment-gated endpoints without subscriptions
Not for
- —Users who need detailed API documentation and request/response schemas before integrating
- —High-volume use cases where per-request pricing may not be cost-effective compared to bulk plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/188 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint works and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation beyond a landing page listing, no request/response examples, and all doc pages render only 'Connect wallet'. The specific purpose of /api/v1/charges/188 ('Premium API Access') is not explained anywhere.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema provided for any endpoint
- —The purpose and expected input/output of /api/v1/charges/188 specifically is undocumented
- —Cannot verify what data or service any of the listed endpoints actually return
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/188
- —Payment settles to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/v1/charges/188