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 spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are paid per-request using USDC on the Base network, with no API keys, no rate limits, and no minimum commitments required. The specific endpoint at `/api/v1/transactions/3` is labeled "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per call (USDC uses 6 decimals).
The platform advertises four categories of APIs: 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 are listed at the same $0.02 price point. Payment is handled via the x402 protocol's exact scheme, settling on the Base L2 network.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. The actual functionality behind the "Premium API Access" label at `/api/v1/transactions/3` is unclear, as it does not correspond to any of the named API categories on the landing page.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification) without managing API keys
- —Fetching real-time crypto price feeds and gas estimates with per-call USDC payments
- —Running geocoding or data validation utilities with no subscription commitment
- —Exporting analytics data or generating insights on a pay-as-you-go basis
Fit
Best for
- —Developers or agents wanting zero-friction, keyless API access paid in USDC
- —Low-volume or bursty workloads where per-request pricing avoids subscription waste
- —Web3-native applications that prefer on-chain settlement for API calls
Not for
- —High-volume production workloads needing SLAs, rate-limit guarantees, or detailed documentation
- —Users without access to USDC on the Base network
- —Applications requiring well-documented, schema-validated API contracts
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/3 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no meaningful documentation beyond the landing page listing. The specific endpoint path '/api/v1/transactions/3' is not described anywhere on the site. Effectively a stub listing.
Warnings
- —No OpenAPI schema or detailed documentation available for any endpoint
- —The /docs, /pricing, /api, and /README pages all render only 'Connect wallet' with no content
- —The endpoint path /api/v1/transactions/3 ('Premium API Access') does not match any of the named APIs on the landing page — its actual functionality is unknown
- —No request or response examples are available anywhere in the crawled material
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/transactions/3 requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/3
- —The platform offers APIs in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com