Pay-per-call API platform on Base network via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad suite of endpoints spanning data analytics, AI/ML inference, finance/crypto data, and utility services. All endpoints are paid per-request at $0.02 each using USDC on the Base network, with no API keys, rate limits, or subscription commitments required.
The specific endpoint at `/api/v1/charges/25` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme with a 300-second timeout. The endpoint accepts HTTP POST and returns application/json.
The broader 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, documentation pages beyond the landing page are essentially empty (showing only "Connect wallet"), so the actual behavior, request schemas, and response formats for these endpoints are undocumented in the crawled material.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification) without managing API keys
- —Fetching real-time crypto token quotes and gas estimates via micropayment
- —Running geocoding or data validation calls with no subscription overhead
- —Exporting analytics data or generating insights on a per-request basis
Fit
Best for
- —AI agents that need key-free, pay-as-you-go access to diverse API endpoints
- —Developers prototyping with low-cost per-call pricing on Base/USDC
- —Web3-native applications that prefer on-chain payment settlement
Not for
- —High-volume production workloads where subscription pricing would be cheaper
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/25 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty stubs. The specific purpose of the '/api/v1/charges/25' endpoint beyond 'Premium API Access' is unclear, and the broader platform's endpoint behaviors are entirely undocumented.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) are all empty — only 'Connect wallet' is rendered.
- —No OpenAPI or schema available for any endpoint; request and response formats are unknown.
- —The specific function of /api/v1/charges/25 ('Premium API Access') is ambiguous — it is not listed among the categorized endpoints on the landing page.
- —Cannot verify that the advertised AI, finance, and utility endpoints actually function as described.
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base (equals $0.02)https://lowpaymentfee.com/api/v1/charges/25
- —Payment settles to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 on Base networkhttps://lowpaymentfee.com/api/v1/charges/25