Pay-per-call API platform on Base via x402 — data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request 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, paid in USDC on the Base network.
The specific endpoint at `/api/v1/charges/217` is labeled "Premium API Access" and returns a valid x402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02. Payment is made via the x402 exact scheme with no API keys or rate limits required. The endpoint accepts HTTP POST and returns application/json.
Documentation is extremely sparse — the docs, pricing, API, and README pages all render 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 endpoint actually returns. The platform's landing page lists the available endpoints and pricing but provides no details on request parameters or response formats. As a result, while the endpoint is confirmed live and the payment mechanics are clear, the actual functionality behind "Premium API Access" at this specific charge ID is unknown.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data such as token quotes, gas estimates, and exchange rates on a per-call basis
- —Running data analytics queries and exporting data with no subscription commitment
- —Using utility services like geocoding, validation, and conversion via micropayments
Fit
Best for
- —Agents or developers who want instant, keyless API access paid per request
- —Low-volume or bursty workloads where subscription pricing is wasteful
- —x402-compatible agents that can settle USDC payments on Base automatically
Not for
- —High-volume production workloads where per-request pricing at $0.02 adds up quickly
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/217 \
-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 documentation of request parameters or response schemas, and the specific functionality of '/api/v1/charges/217' ("Premium API Access") is undefined. The docs/pricing/README pages are all empty beyond a wallet connect prompt.
Warnings
- —No OpenAPI or schema documentation available — request/response formats are unknown
- —The specific endpoint /api/v1/charges/217 is labeled 'Premium API Access' but its actual functionality is not documented anywhere
- —All non-landing pages (docs, pricing, README, api) return only a 'Connect wallet' prompt with no content
- —No examples of successful responses are available
Citations
- —The endpoint returns a 402 x402 challenge requesting up to 20,000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/217
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/217
- —All 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 across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com