x402-gated API collection on Base — pay $0.02 per request in USDC, no API keys required.
What it does
lowpaymentfee.com hosts a suite of x402-protocol pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint costs $0.02 per request, settled in USDC on the Base network. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/collections/44` is listed as "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x8335…2913 on Base, 6 decimals), which equals $0.02. The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises endpoints in four categories: 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). Documentation pages exist but appear gated behind a wallet connection, so detailed request/response schemas are not publicly available.
Capabilities
Use cases
- —Agent-driven data retrieval without managing API keys or subscriptions
- —On-demand AI inference (sentiment, summarization, classification, embeddings) paid per call
- —Fetching real-time crypto prices, gas estimates, and exchange rates via micropayment
- —Geocoding and data conversion utilities for automated pipelines
Fit
Best for
- —AI agents that need frictionless, keyless API access with crypto micropayments
- —Developers prototyping against multiple API categories without signup
- —Low-volume or bursty workloads where per-request pricing beats subscriptions
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —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/collections/44 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint works and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documented request/response format, and all docs pages are gated behind wallet connection, leaving the actual functionality of /collections/44 opaque.
Warnings
- —No public documentation — all doc pages return only a 'Connect wallet' prompt, so request/response schemas are unknown.
- —The purpose of /api/v1/collections/44 ('Premium API Access') is vague; it is unclear what data or service it returns.
- —No OpenAPI spec or AI plugin manifest is available.
- —No examples of successful responses could be gathered.
Citations
- —The platform advertises $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/collections/44 specifies maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with a 300-second timeout.https://lowpaymentfee.com/api/v1/collections/44
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com