Pay-per-request API platform on Base via x402 — $0.02/call for data, AI, finance, and utility endpoints.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a suite of endpoints across 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 and settle in USDC on the Base network.
The specific endpoint at `/api/v1/charges/33` is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme with no API keys or rate limits required — callers simply attach an X-PAYMENT header to each request.
Documentation is extremely sparse. The crawled /docs, /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the `/api/v1/charges/33` endpoint actually returns. The endpoint is confirmed live (402 challenge captured), but without documentation it is unclear what data or functionality "Premium API Access" specifically provides versus the other listed endpoints.
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 utility operations like geocoding, validation, and data conversion with instant crypto-settled payments
- —Integrating pay-per-use data analytics and reporting into agent workflows
Fit
Best for
- —Developers wanting zero-signup, pay-per-request API access
- —AI agents that can settle payments in USDC on Base via x402
- —Projects needing low-cost micropayment-gated endpoints without rate limits
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Applications requiring high-volume bulk pricing or subscription plans
- —Developers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/33 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and no examples. The specific purpose of '/api/v1/charges/33' labeled 'Premium API Access' is undefined. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —All documentation pages (/docs, /api, /pricing, /README) return only 'Connect wallet' with no content
- —The specific function of /api/v1/charges/33 ('Premium API Access') is unclear — it does not match any of the named endpoints on the landing page
- —No request or response examples are available anywhere in the crawled material
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and settle on the Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/charges/33 advertises maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/charges/33
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com