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, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/charges/396` 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 HTTP POST 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 price point. However, documentation beyond the landing page is essentially empty (docs, pricing, and API pages all show only a "Connect wallet" prompt), so the actual request/response schemas for individual endpoints are unknown.
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 via micropayment
- —Geocoding or data validation as a utility service with no subscription commitment
- —Exporting analytics data or generating insights on a per-request basis
Fit
Best for
- —AI agents that need stateless, pay-per-call access to diverse utility endpoints
- —Developers prototyping with low-cost API calls and no signup friction
- —Web3-native applications already operating on Base network with USDC
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs
- —Applications requiring non-USDC or non-Base-network payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/396 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, documentation is effectively nonexistent — all doc/pricing/API pages render only a wallet-connect prompt. No request or response schemas are available for any endpoint, and the specific purpose of /api/v1/charges/396 ('Premium API Access') is entirely opaque. The platform lists many endpoints but provides no detail on what inputs they accept or what they return.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) are all empty beyond a 'Connect wallet' prompt — no usable API docs exist
- —No request or response schema is available for this endpoint or any other on the platform
- —The specific function of /api/v1/charges/396 ('Premium API Access') is unclear — it may be a generic charge endpoint rather than a specific service
- —No OpenAPI spec, ai-plugin manifest, or agents.txt is provided
Citations
- —All endpoints priced at $0.02 per request, no API keys, no rate limits, settled 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/charges/396
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com