Pay-per-call API platform on Base via x402 — 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 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 via the x402 protocol.
The specific endpoint at `/api/v1/transfers/140` is listed as "Premium API Access" and advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02. Payment is made inline via the X-PAYMENT header — no API keys, accounts, or rate limits are required. The x402 challenge specifies the "exact" payment scheme with a 300-second timeout.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. The actual functionality behind this particular `/transfers/140` path is unclear — the name "Premium API Access" is generic and does not describe what data or service is returned. Prospective users should be aware that without documentation, the behavior of this endpoint is essentially unknown.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API key signup
- —Fetching real-time finance data (prices, exchange rates, gas estimates) with per-call USDC payment
- —Running utility operations (geocoding, validation, conversion) on a pay-as-you-go basis
- —Integrating agent-purchasable endpoints into autonomous workflows via x402
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle payments via x402 on Base
- —Projects needing low-cost micropayment-gated endpoints
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume use cases where per-request pricing may add up versus subscription models
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/140 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is zero documentation, no OpenAPI schema, no request/response examples, and the specific functionality of /api/v1/transfers/140 is undefined. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —The endpoint path '/api/v1/transfers/140' and label 'Premium API Access' are generic; actual functionality is unknown
- —No OpenAPI schema or request/response examples provided
- —No robots.txt or agents.txt found
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 Base, equaling $0.02https://lowpaymentfee.com/api/v1/transfers/140
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs