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 data, and utility services. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, rate limits, or subscriptions are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/charges/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. The platform also 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.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no description of what the individual endpoints actually accept or return. The 402 challenge confirms the endpoint is live and uses x402 version 1 with the "exact" payment scheme, a 300-second timeout, and outputs application/json via HTTP POST.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes, gas estimates, or exchange rates with per-call payment
- —Geocoding or data validation as a utility service with no subscription commitment
- —Exporting analytics data or generating insights on a pay-as-you-go basis
Fit
Best for
- —AI agents that need low-friction, keyless API access via x402
- —Developers wanting to prototype with multiple API categories at a flat $0.02/call
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/233 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages return only 'Connect wallet' with no useful content. The purpose of this specific endpoint (/api/v1/charges/233) is unclear beyond the generic label 'Premium API Access'.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only 'Connect wallet' with no substantive content
- —No OpenAPI or schema available — request and response formats are unknown
- —The specific purpose of /api/v1/charges/233 ('Premium API Access') is not documented; it is unclear how it differs from other listed endpoints
- —No information on uptime, SLAs, or data sources behind any of the advertised endpoints
Citations
- —All endpoints priced at $0.02/request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —402 challenge requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/233
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com