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 priced at $0.02 per request, payable 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 to each request and receive the response immediately.
The specific endpoint at `/api/v1/payments/233` 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 generation — all at the same $0.02 price point. However, documentation beyond the landing page is essentially empty (all subpages 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 input parameters and output formats.
Capabilities
Use cases
- —Programmatic access to various utility and data APIs without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers exploring x402 payment protocol with minimal cost
- —AI agents needing keyless, pay-per-call API access
- —Projects wanting to avoid subscription commitments for occasional API usage
Not for
- —Production workloads requiring well-documented request/response schemas
- —Use cases needing detailed SLA guarantees or support
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/233 \
-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 it works. However, there is no OpenAPI spec, no documentation (all doc pages are empty), no request/response schema, and the specific purpose of the /payments/233 endpoint beyond 'Premium API Access' is unclear. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all doc/pricing/API pages return only 'Connect wallet'
- —The specific functionality of /api/v1/payments/233 ('Premium API Access') is not described anywhere
- —Request body format and response structure are completely unknown
- —No SLA, rate limit, or uptime guarantees documented
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 requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/payments/233
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com