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 set of endpoints across data analytics, AI/ML inference, finance/Web3, and utility services. All endpoints are paid per-request using USDC on the Base network at $0.02 per call, with no API keys, no rate limits, and no commitments required. The specific endpoint at `/api/v1/transactions/13` is listed as "Premium API Access" and returns an x402 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 behavior and response schemas of these endpoints are unknown.
The x402 challenge is live and well-formed: it specifies the exact payment scheme on Base, paying to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`, with a 300-second timeout. The endpoint accepts POST requests. Without documentation or example responses, the actual data returned by this specific transactions endpoint remains unclear.
Capabilities
Use cases
- —Accessing analytics metrics and reports without API key management
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) on a per-call payment basis
- —Fetching real-time crypto prices, gas estimates, and exchange rates
- —Performing utility operations like geocoding, validation, and data conversion
Fit
Best for
- —Developers wanting zero-friction API access without signup or API keys
- —Agents and bots that can settle payments in USDC on Base
- —Low-volume or bursty workloads where per-call pricing is cost-effective
Not for
- —High-volume production workloads needing guaranteed SLAs and detailed documentation
- —Users without a Base-compatible USDC wallet
- —Applications requiring well-documented response schemas and error handling
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/13 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02/request in USDC on Base). However, all documentation pages return only 'Connect wallet' with no actual content. There is no OpenAPI schema, no example requests or responses, and the specific purpose of the /api/v1/transactions/13 endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —All documentation pages (docs, api, pricing, README) returned no substantive content — only 'Connect wallet' prompts.
- —No OpenAPI or schema documentation available for any endpoint.
- —The specific behavior and response format of /api/v1/transactions/13 is undocumented and unclear.
- —The platform lists many endpoint categories but without documentation it is impossible to verify they function as described.
Citations
- —The endpoint returns a 402 x402 challenge requesting up to 20,000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/13
- —USDC contract address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/13
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com