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 broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are priced at $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no commitments required. The specific endpoint at `/api/v1/transactions/273` is labeled "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02, since USDC uses 6 decimals) on Base.
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). However, the crawled documentation pages (docs, api, pricing, README) all returned only a "Connect wallet" prompt with no substantive content, so the actual functionality behind these endpoints is unverified. There is no OpenAPI schema, no example request/response documentation, and no detailed description of what the `/api/v1/transactions/273` endpoint specifically does.
The x402 challenge is live and well-formed: it specifies the USDC contract on Base (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), a 300-second timeout, and accepts POST requests. The payment address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3.
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
- —Running data analytics queries and exporting reports on a per-request billing model
- —Using utility services like geocoding, validation, and data conversion with micropayments
Fit
Best for
- —Developers wanting zero-setup, pay-as-you-go API access via crypto micropayments
- —AI agents that can autonomously pay for API calls using x402 on Base
- —Projects needing low-cost, keyless access to a variety of utility and data endpoints
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Teams requiring non-crypto payment methods or fiat invoicing
- —High-volume production workloads where per-request pricing at $0.02 may not be cost-effective
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/273 \
-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 schema, no documentation content (all doc pages return only 'Connect wallet'), no example requests or responses, and the specific purpose of the /api/v1/transactions/273 endpoint is undefined beyond the generic label 'Premium API Access'.
Warnings
- —All documentation pages (/docs, /api, /pricing, /README) returned only 'Connect wallet' with no actual content
- —No OpenAPI or schema available — endpoint input/output formats are unknown
- —The specific functionality of /api/v1/transactions/273 is unclear; 'Premium API Access' is a generic label
- —The breadth of advertised capabilities (AI, finance, analytics, utilities) is unverified
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 (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/273
- —Platform advertises Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com
- —Documentation pages returned only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs