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. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no commitments required. The x402 protocol handles payment inline: callers attach a payment header and the server fulfills the request upon verification.
The specific endpoint at `/api/v1/transactions/314` is listed as "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 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
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 to require wallet connection to view, so detailed request/response schemas are not available from the crawl.
Capabilities
Use cases
- —Querying real-time crypto price feeds and gas estimates without API key management
- —Running AI inference tasks (sentiment, summarization, classification) on a per-call payment basis
- —Accessing geocoding and data conversion utilities with instant USDC micropayments
- —Exporting analytics data and insights via pay-as-you-go endpoints
Fit
Best for
- —Developers who want instant API access without signup or API key provisioning
- —Agents and bots that can settle payments programmatically via x402 on Base
- —Low-volume or bursty workloads where per-request pricing is more economical than subscriptions
Not for
- —High-volume production workloads where bulk pricing or subscriptions would be cheaper
- —Users without a Base-network USDC wallet or x402-compatible client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/314 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base). However, documentation pages all resolve to a wallet-connect prompt with no actual content, so there are no request/response schemas, no OpenAPI spec, and no concrete examples of what the endpoints return. The specific endpoint '/api/v1/transactions/314' has no description beyond 'Premium API Access', making its actual function unclear.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only a 'Connect wallet' prompt — no usable docs are publicly accessible.
- —No OpenAPI or schema available; request and response formats are unknown.
- —The specific endpoint /api/v1/transactions/314 is not listed among the advertised endpoints on the homepage — its purpose is unclear.
- —The platform advertises many endpoint categories (AI, finance, analytics, etc.) but without accessible docs it is impossible to verify they actually function.
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/314
- —Platform offers endpoints in Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com