Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/invoices/35` is labeled "Premium API Access" and charges up to $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys or accounts are required — callers authenticate and pay via the x402 protocol's `X-PAYMENT` header.
The platform advertises four categories of endpoints: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All listed endpoints are priced at $0.02 per request with no rate limits or minimum commitments.
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 schema, no request/response examples, and no detailed description of what the `/api/v1/invoices/35` endpoint specifically returns. The x402 challenge confirms the endpoint is live and accepts POST requests, but the actual functionality behind "Premium API Access" is unclear from available materials.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key signup
- —Fetching real-time financial data like token quotes, gas estimates, and exchange rates on a per-call basis
- —Running data analytics queries and exporting data with instant crypto-settled micropayments
- —Using utility services like geocoding and validation without rate limits or subscriptions
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle payments via x402 on Base
- —Projects needing low-cost micropayment-settled API calls without accounts
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Applications requiring guaranteed SLAs or enterprise support
- —Callers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/invoices/35 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The x402 challenge confirms the endpoint is live and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what 'Premium API Access' at /api/v1/invoices/35 actually returns. All doc pages render only 'Connect wallet' with no content.
Warnings
- —No documentation available — all doc/API/pricing/README pages show only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific functionality of /api/v1/invoices/35 ('Premium API Access') is undefined in available materials
- —No examples of request bodies or response payloads anywhere in crawled content
- —Platform appears to be a demo or early-stage project with placeholder content
Citations
- —The endpoint charges up to 20,000 base units of USDC (asset 0x8335…) on Base, which equals $0.02https://lowpaymentfee.com/api/v1/invoices/35
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages all render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs