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/charges/140` is listed as "Premium API Access" and advertises a max amount of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The x402 challenge confirms the endpoint is live, accepts POST requests, and returns application/json. The payment timeout is 300 seconds.
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. However, the crawled documentation pages (docs, pricing, README) returned only wallet-connect stubs with no substantive content, so the actual behavior and response schemas of these endpoints remain undocumented. Without request/response examples or OpenAPI specs, the precise inputs and outputs for this endpoint are unknown.
Capabilities
Use cases
- —Programmatic access to premium API services without account signup or API key management
- —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
- —AI agents needing keyless, pay-per-call API access
- —Users who want to avoid subscription commitments for occasional API calls
Not for
- —Users needing detailed API documentation or OpenAPI schemas before integrating
- —High-volume use cases where per-request pricing may add up compared to bulk plans
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/140 \
-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 request/response schema, no documentation content (all doc pages return only a wallet-connect stub), and the actual functionality behind 'Premium API Access' at /charges/140 is entirely opaque.
Warnings
- —No OpenAPI or schema documentation available — endpoint inputs and outputs are unknown
- —All documentation pages (/docs, /pricing, /README, /api) returned only 'Connect wallet' with no substantive content
- —The specific purpose of /api/v1/charges/140 ('Premium API Access') is unclear and may be a generic or placeholder endpoint
- —Cannot verify what data or service is actually returned upon successful payment
Citations
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/charges/140
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com