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. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no upfront commitments. The specific endpoint at `/api/v1/transactions/84` is listed as "Premium API Access" and returns `application/json` via POST.
The platform advertises four main categories of APIs: (1) Data & Analytics — metrics, reports, data export, and insights; (2) AI & Machine Learning — sentiment analysis, text summarization, classification, and embeddings; (3) Finance & Web3 — price feeds, exchange rates, token quotes, and gas estimates; (4) Infrastructure — geocoding, validation, conversion, and generation utilities. All endpoints follow the x402 payment protocol, where callers attach an `X-PAYMENT` header containing a signed USDC payment to unlock the response.
The probe confirmed the endpoint is live, returning a proper 402 challenge with `maxAmountRequired` of 20000 base units of USDC (6 decimals), which equals $0.02. Payment is sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base. Documentation pages beyond the landing page were largely empty (showing only "Connect wallet"), so details about request/response schemas, specific data sources, or model specifications are unavailable.
Capabilities
Use cases
- —Querying real-time financial data or exchange rates without an API key
- —Running AI inference (sentiment, summarization, classification, embeddings) on a per-call basis
- —Accessing utility services like geocoding or data validation with micropayments
- —Exporting analytics data or generating insights reports
Fit
Best for
- —Developers who want instant API access without signup or API key management
- —Agents or bots that can settle USDC payments on Base per request
- —Low-volume or bursty workloads where pay-per-call is more economical than subscriptions
Not for
- —High-volume production workloads where $0.02/request adds up quickly
- —Users who cannot transact in USDC on the Base network
- —Applications requiring detailed SLAs, guaranteed uptime, or support contracts
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/84 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation pages are effectively empty ('Connect wallet' only), there is no OpenAPI schema, no request/response examples, and the specific purpose of the '/api/v1/transactions/84' endpoint labeled 'Premium API Access' is unclear. The broad catalog claims cannot be verified.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) are all empty beyond a 'Connect wallet' prompt — no usable docs available.
- —The specific function of /api/v1/transactions/84 ('Premium API Access') is not described anywhere; it may be a generic or placeholder endpoint.
- —No OpenAPI schema or request/response examples are provided for any endpoint.
- —The breadth of advertised capabilities (AI, finance, analytics, utilities) cannot be verified from available material.
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge shows maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base.https://lowpaymentfee.com/api/v1/transactions/84
- —Platform offers APIs in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com