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 paid per-request at $0.02 each using USDC on the Base network, with no API keys, no rate limits, and no commitments required. The specific endpoint at `/api/v1/transactions/117` is labeled "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 functionality behind each endpoint is unverified.
The x402 challenge is live and well-formed, settling payments to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base. The endpoint accepts POST requests and returns `application/json`. Without documentation or example responses, the exact data returned by this particular transactions endpoint is unknown.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time finance and crypto market data on a per-request basis
- —Running data analytics queries and exporting reports with micropayments
- —Using utility services like geocoding and validation without subscription commitments
Fit
Best for
- —Developers wanting zero-friction, keyless API access via crypto micropayments
- —Agents and bots that need on-demand API calls settled in USDC on Base
- —Low-volume or sporadic API consumers who don't want subscriptions
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users without a Base-compatible wallet or USDC holdings
- —Anyone needing detailed SLAs, documentation, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/117 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and accepts payment. However, documentation pages are empty (all show only 'Connect wallet'), there is no OpenAPI schema, no example requests or responses, and the actual functionality of the /api/v1/transactions/117 endpoint is unclear. The listing is effectively a stub with pricing info.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all returned no content — only a 'Connect wallet' prompt.
- —No OpenAPI or schema available; actual request/response format for this endpoint is unknown.
- —The specific purpose of /api/v1/transactions/117 ('Premium API Access') is not documented — it may be a generic or placeholder endpoint.
- —The breadth of advertised endpoints (AI, finance, analytics, utils) is unverified; actual functionality behind each is unknown.
Citations
- —All endpoints priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base (=$0.02)https://lowpaymentfee.com/api/v1/transactions/117
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/117
- —Platform advertises Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com