Pay-per-call API platform on Base (USDC) via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are paid per-request using USDC on the Base network, with a uniform price of $0.02 per call. The x402 protocol eliminates the need for API keys or account registration — callers simply attach a payment header to each request.
The specific endpoint at `/api/v1/payments/90` is listed as "Premium API Access" and returns a 402 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 for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. Documentation pages exist but appear to require a wallet connection to view, so detailed request/response schemas for individual endpoints are not available from the crawl.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification) without managing API keys
- —Fetching real-time crypto token quotes or gas estimates with per-call payment
- —Geocoding or data validation as a utility service within automated workflows
- —Exporting analytics data or generating insights reports on demand
- —Programmatic access to exchange rates and price feeds for DeFi applications
Fit
Best for
- —AI agents and bots that can pay per-request via x402 on Base
- —Developers who want instant API access without signup or rate limits
- —Low-volume or bursty workloads where flat subscription pricing is wasteful
Not for
- —High-volume production workloads where per-call costs add up quickly
- —Users without a Base-network USDC wallet or x402-compatible client
- —Anyone needing detailed API documentation before integrating (docs are sparse)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/90 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation pages are gated behind wallet connection, no OpenAPI schema is available, and there are no request/response examples for this specific endpoint. The endpoint path '/api/v1/payments/90' is generic and its actual functionality beyond 'Premium API Access' is unclear.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) all appear to require wallet connection and returned no useful content during crawl.
- —No OpenAPI or schema documentation is available — request and response formats for this endpoint are unknown.
- —The endpoint path '/api/v1/payments/90' does not match any of the named endpoints listed on the homepage; its specific functionality is unclear.
- —The 'Premium API Access' description is generic and does not explain what data or service this endpoint provides.
Citations
- —Uniform pricing of $0.02 per request across all endpointshttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base (= $0.02)https://lowpaymentfee.com/api/v1/payments/90
- —Available endpoint categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com