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 variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/payments/71` 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 per call. However, documentation beyond the landing page is extremely sparse; the docs, API, pricing, and README pages all appear to require a wallet connection and contain no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material.
Capabilities
Use cases
- —Agent-driven API calls where per-request micropayments replace API key management
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without subscriptions
- —Fetching real-time crypto/finance data (token quotes, gas estimates, exchange rates) on demand
- —Geocoding and data validation utilities paid per use
Fit
Best for
- —AI agents that need frictionless, keyless API access via x402
- —Developers prototyping with low-cost, no-commitment API calls
- —Web3-native applications already operating on the Base network
Not for
- —High-volume production workloads where per-request pricing becomes expensive compared to bulk plans
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/71 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, documentation is essentially nonexistent — all doc/pricing/README pages require wallet connection and show no content. There is no OpenAPI spec, no request/response schemas, and no examples. The specific purpose of the '/payments/71' endpoint beyond 'Premium API Access' is unclear.
Warnings
- —No OpenAPI specification or request/response schema available
- —Documentation pages (docs, pricing, README, api) are empty or require wallet connection — no substantive docs found
- —The specific functionality of /api/v1/payments/71 ('Premium API Access') is not documented; it is unclear what data or service it returns
- —No examples of successful responses are available
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 returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/payments/71
- —Platform offers endpoints for analytics, AI/ML (sentiment, summarization, classification, embeddings), finance (prices, rates, quotes, gas), and utilities (geocode, validate, convert, generate)https://lowpaymentfee.com