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/transactions/55` is listed as "Premium API Access" and advertises a maxAmountRequired of 20,000 base units of USDC (0x8335… on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and returns application/json. The x402 challenge confirms the endpoint is live and version 1 compliant with a 300-second payment timeout.
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. However, documentation beyond the landing page is essentially empty (all sub-pages just show "Connect wallet"), so the actual request/response schemas for individual endpoints are unknown. Without documentation or OpenAPI specs, callers will need to experiment to discover required input fields and response formats.
Capabilities
Use cases
- —Accessing premium API endpoints without creating accounts or managing API keys
- —Making one-off API calls with instant USDC micropayments on Base
- —Agent-driven workflows that need pay-as-you-go API access without subscriptions
Fit
Best for
- —Developers who want zero-friction API access without signup
- —AI agents that can autonomously pay for API calls via x402
- —Users already holding USDC on Base who want instant access
Not for
- —Users who need detailed API documentation and request/response schemas before integrating
- —High-volume callers who would benefit from bulk pricing or subscription discounts
- —Developers without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/55 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is no OpenAPI spec, no documentation, no request/response schemas, and all doc pages are empty stubs. The specific purpose of /api/v1/transactions/55 ('Premium API Access') is vague and undocumented. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request/response formats are unknown
- —All documentation pages (/docs, /api, /pricing, /README) return only 'Connect wallet' with no actual content
- —The specific endpoint /api/v1/transactions/55 has a generic 'Premium API Access' description with no details on what it actually does
- —Cannot verify what data or service this specific endpoint provides
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —maxAmountRequired is 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/55
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com