Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. Every endpoint is priced at $0.02 per request, settled in USDC on the Base network. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/customers/43` is listed as "Premium API Access" and returns `application/json` via POST. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
Documentation beyond the landing page is extremely sparse — 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 available. The purpose of the `/api/v1/customers/43` endpoint specifically is unclear; it may be a demo or sample resource. The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, and data export, all at the same $0.02 price point.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —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 pricing
- —Using utility services like geocoding, validation, and conversion via x402 micropayments
Fit
Best for
- —Agents and bots that need keyless, pay-per-call API access
- —Developers prototyping with multiple API categories without subscription commitments
- —Web3-native applications already holding USDC on Base
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads where per-request pricing may add up compared to bulk plans
- —Users without USDC on Base or unfamiliar with x402 payment protocol
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/customers/43 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page, and the specific purpose of /api/v1/customers/43 is unexplained. Most doc pages render only 'Connect wallet' with no content.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —All documentation pages (/docs, /pricing, /api, /README) return only a 'Connect wallet' prompt with no useful content
- —The specific endpoint /api/v1/customers/43 is not listed on the landing page catalog — its purpose is unclear
- —No request body schema or response examples are documented anywhere
- —The breadth of advertised endpoints (AI, finance, data, utils) is unverifiable without documentation
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with 300s timeouthttps://lowpaymentfee.com/api/v1/customers/43
- —Platform advertises endpoints for analytics, AI (sentiment, summarization, classification, embeddings), finance, and utilitieshttps://lowpaymentfee.com
- —Documentation pages /docs, /pricing, /api, /README render only 'Connect wallet'https://lowpaymentfee.com/docs