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 & machine learning, finance & Web3, and infrastructure utility categories. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, rate limits, or commitments are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/item/3` is listed as "Premium API Access" and returns `application/json`. The x402 challenge indicates a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using the "exact" scheme with a 300-second 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 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 functionality, request/response schemas, and data sources behind each endpoint are unknown. The `/api/v1/item/3` endpoint specifically lacks any description of what data or service it provides beyond the generic "Premium API Access" label.
Capabilities
Use cases
- —Programmatic access to various API services without needing API key registration
- —Agent-driven workflows that need on-demand API calls with crypto micropayments
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers wanting zero-friction API access without signup or API keys
- —AI agents that can settle payments via x402 on Base
- —Users comfortable paying per-request in USDC on Base network
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Anyone requiring free or subscription-based API access
- —Production workloads that depend on well-documented request/response contracts
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/item/3 \
-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 accepts payments. However, there is no documentation, no OpenAPI schema, no request/response examples, and the purpose of `/api/v1/item/3` ("Premium API Access") is completely opaque. All doc pages return only "Connect wallet" with no actual content.
Warnings
- —The specific endpoint /api/v1/item/3 has no description of what it actually does — 'Premium API Access' is a generic label
- —All documentation pages (docs, api, pricing, README) are empty, showing only 'Connect wallet'
- —No OpenAPI spec, no request schema, no response schema available
- —The actual data or service behind this endpoint is unknown — callers cannot predict what they will receive for $0.02
Citations
- —All endpoints priced at $0.02 per request, no API keys, no rate limits, Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base with 300s timeouthttps://lowpaymentfee.com/api/v1/item/3
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/item/3
- —Platform lists endpoints across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com