Pay-per-call API platform on Base (USDC) covering 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 endpoints spanning data analytics, AI/ML inference, finance/Web3 market data, and general utility services. Every endpoint is priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol. There are no API keys, no rate limits, and no upfront commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/332` is listed as "Premium API Access" and returns `application/json`. Its x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and is discoverable. Payment is sent to `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout.
The broader 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). Documentation pages exist but appear to require a wallet connection and contain no visible content, so the actual request/response schemas for individual endpoints are unknown.
Capabilities
Use cases
- —Querying real-time financial data or exchange rates without managing API keys
- —Running AI inference tasks (sentiment, summarization, classification) on a per-call payment basis
- —Accessing geocoding or data conversion utilities with no subscription commitment
- —Fetching gas estimates or token quotes for Web3 applications
- —Exporting analytics data or generating insights on demand
Fit
Best for
- —Agents or bots that need keyless, on-demand API access paid per call
- —Developers prototyping across multiple API categories without subscription overhead
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where per-call pricing becomes expensive compared to subscription plans
- —Users who cannot transact in USDC on the Base network
- —Applications requiring detailed SLAs, guaranteed uptime, or enterprise support
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/332 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, documentation pages are empty (wallet-gated), there is no OpenAPI spec, no request/response schema, and no examples. The purpose of this specific '/transactions/332' endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only 'Connect wallet' with no visible content — actual API schemas and behavior are undocumented.
- —The specific endpoint /api/v1/transactions/332 is labeled 'Premium API Access' but its exact functionality is unknown; it does not appear in the site's listed API catalog.
- —No OpenAPI spec or request/response schema is available for any endpoint.
- —No information on uptime guarantees, rate limits (site claims none), or data freshness.
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 shows maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/332
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com
- —Payment address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with 300-second timeouthttps://lowpaymentfee.com/api/v1/transactions/332