Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that gates access behind x402 micropayments settled in USDC on the Base network. The specific endpoint `/api/v1/lab/results/44` is listed under "Premium API Access" and costs up to $0.02 per call (maxAmountRequired of 20,000 base units of USDC, i.e. 20000 / 10^6 = $0.02). No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.
The broader platform offers 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 uniformly priced at $0.02 per request.
This particular endpoint (`/api/v1/lab/results/44`) appears to be a specific lab result resource. However, the crawled documentation does not describe what "lab results" contain or what the expected request/response payloads look like. The endpoint accepts POST requests and returns `application/json`. Payment is made to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base.
Capabilities
Use cases
- —Fetching specific lab result data via a single paid API call
- —Programmatic access to premium data without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand data retrieval with crypto micropayments
Fit
Best for
- —Developers wanting zero-friction, keyless API access paid in USDC
- —AI agents that can settle x402 payments autonomously on Base
- —Use cases requiring low-cost per-call pricing without rate limits
Not for
- —Users who need free or ad-supported API access
- —High-volume batch processing where per-call pricing becomes expensive
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/lab/results/44 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base). However, there is no documentation on what '/api/v1/lab/results/44' actually returns, no request/response schema, and no examples. The 'lab results' concept is not explained anywhere in the crawled material, making this effectively a stub listing.
Warnings
- —No documentation found for the specific '/api/v1/lab/results/44' endpoint — its purpose and response format are unknown.
- —This endpoint does not appear in the site's listed API catalog, which raises questions about its intended use.
- —No OpenAPI spec, request schema, or response schema available.
- —No examples of request or response payloads could be found.
Citations
- —The endpoint returns a 402 challenge requiring USDC payment on Base with maxAmountRequired of 20000 base units ($0.02).https://lowpaymentfee.com/api/v1/lab/results/44
- —All endpoints on the platform are priced at $0.02 per request with no API keys, rate limits, or commitments.https://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 and payTo address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3.https://lowpaymentfee.com/api/v1/lab/results/44