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 broad set of endpoints spanning 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 probed (/api/v1/transfers/125) is labeled "Premium API Access" and returns a valid 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 platform advertises additional endpoint categories including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, gas estimates, geocoding, validation, conversion, and data export — 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 further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The actual functionality behind each endpoint cannot be verified from the available material, so the precise inputs and outputs remain unknown.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification) without API key management
- —Fetching real-time crypto token quotes or gas estimates via a single paid HTTP call
- —Geocoding or data validation as a utility microservice with per-request billing
- —Exporting analytics data or generating reports with zero subscription commitment
Fit
Best for
- —AI agents that need simple, keyless, per-call API access
- —Developers wanting to avoid API key provisioning and subscription overhead
- —Low-volume or bursty workloads where flat per-request pricing is economical
Not for
- —High-volume production workloads where $0.02/request adds up quickly
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
- —Applications requiring non-USDC or non-Base-network payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/125 \
-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 USDC payments on Base at $0.02/request. However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schemas, and no examples. The actual functionality behind 'Premium API Access' and the other listed endpoints cannot be verified.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README all render only 'Connect wallet'
- —No OpenAPI or schema definitions found; request/response formats are unknown
- —The specific endpoint /api/v1/transfers/125 is labeled generically as 'Premium API Access' with no description of what it actually does
- —Cannot verify that the advertised AI, finance, and utility endpoints are functional
Citations
- —All endpoints priced at $0.02/request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —Endpoint categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —x402 challenge requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/transfers/125
- —Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/v1/transfers/125