x402-gated API collection on Base — pay $0.02 per request in USDC, no 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 is gated by an x402 payment challenge: callers attach a USDC payment on the Base network in the X-PAYMENT header and receive the response immediately — no API keys, no accounts, no rate limits.
The specific endpoint `/api/v1/collections/10` is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The site's landing page confirms a flat $0.02/request price across all endpoints.
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 utilities (geocoding, validation, conversion, generation). Documentation pages beyond the landing page returned only a "Connect wallet" prompt with no further technical detail, so request/response schemas for this specific collection endpoint are unknown.
Capabilities
Use cases
- —Agents that need on-demand API access without pre-registration or API key management
- —Programmatic access to a bundle of data, AI, finance, and utility endpoints via a single payment protocol
- —Testing x402 payment flows against a live, low-cost endpoint
Fit
Best for
- —AI agents with x402-compatible wallets looking for frictionless API consumption
- —Developers prototyping x402 payment integrations on Base
- —Use cases requiring small, one-off API calls without subscription commitments
Not for
- —High-volume batch workloads where per-request micropayments add up quickly
- —Users who need detailed API documentation or guaranteed SLAs
- —Callers without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/10 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no OpenAPI schema, no documentation beyond a landing page, and no example request/response bodies. The purpose of the '/collections/10' endpoint specifically is unclear beyond the generic label 'Premium API Access'. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown.
- —All documentation pages (/docs, /api, /pricing, /README) returned only 'Connect wallet' with no usable content.
- —The specific purpose of /api/v1/collections/10 is not described anywhere; 'Premium API Access' is a generic label.
- —No information on uptime, SLAs, or data freshness guarantees.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/collections/10
- —The site advertises $0.02/request flat pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/collections/10