Pay-per-call API suite on Base (USDC) covering analytics, AI, finance, and utilities at $0.02/request.
What it does
lowpaymentfee.com offers a collection of x402-enabled API endpoints spanning four categories: 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 endpoints are priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol.
The specific endpoint listed here (`/api/endpoint-1`) is described as "Premium API Access" and returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0.02 USD). Payment is made to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base. The endpoint accepts HTTP POST requests and returns `application/json` responses. No API keys or rate limits are advertised; access is gated purely by per-call micropayment.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI schema, no request/response examples, and no description of what `/api/endpoint-1` actually returns. The site lists 16 other named endpoints at versioned paths (e.g., `/api/v2/ai/sentiment`), but this endpoint's path (`/api/endpoint-1`) does not match any of them, so its specific functionality is unclear.
Capabilities
Use cases
- —Programmatic access to analytics, AI inference, finance data, or utility services via micropayment
- —Agent-driven workflows that need keyless, per-call API access settled in USDC on Base
- —Testing x402 payment flows against a low-cost endpoint
Fit
Best for
- —Developers exploring x402 micropayment-gated APIs
- —AI agents that can settle USDC payments on Base per request
- —Users who want no-signup, no-API-key access to utility endpoints
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who prefer subscription or bulk pricing over per-call payments
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-1 \
-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 pricing and payment details. However, there is no OpenAPI schema, no request/response examples, and no documentation beyond a wallet-connect prompt. The specific functionality of /api/endpoint-1 is undocumented and does not correspond to any of the named endpoints on the landing page.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —The path /api/endpoint-1 does not match any of the 16 named endpoints listed on the site; its actual functionality is unknown
- —No OpenAPI schema or request/response examples provided
- —No information on what data or service this specific endpoint returns
Citations
- —All endpoints priced at $0.02 per request 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 (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/endpoint-1
- —Site lists 16 endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only 'Connect wallet' with no additional contenthttps://lowpaymentfee.com/docs