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 variety of endpoints across data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, no rate limits, and no commitments required. The x402 protocol handles payment inline: callers attach a payment header to each request and receive the response immediately.
The specific endpoint at `/api/v1/customers/83` is listed as "Premium API Access" and returns `application/json`. Based on the x402 challenge, it accepts POST requests and charges a maximum of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call, settled on the Base L2 network to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3`. The broader platform advertises additional endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, and more — all at the same $0.02 price point.
Documentation is extremely sparse. The /docs, /pricing, /api, 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 data or functionality behind the `/api/v1/customers/83` endpoint is unclear — the name "Premium API Access" is generic and does not describe what data is returned.
Capabilities
Use cases
- —Accessing premium data endpoints without API key registration
- —Making one-off API calls with per-request USDC micropayments
- —Agent-driven workflows that need keyless, pay-as-you-go API access
Fit
Best for
- —Developers who want zero-signup API access via crypto micropayments
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer pay-per-call pricing over subscription models
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/customers/83 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the purpose of the /customers/83 endpoint is entirely opaque. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No OpenAPI spec or schema documentation available
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no content
- —The purpose and response format of /api/v1/customers/83 is unknown — 'Premium API Access' is a generic label
- —No request body schema or response schema documented anywhere
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 (USD Coin) on Base networkhttps://lowpaymentfee.com/api/v1/customers/83
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/customers/83