Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API marketplace that exposes a broad set of endpoints across four categories: Data & Analytics (metrics, reports, 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, settled in USDC on the Base network via the x402 protocol.
The specific endpoint at `/api/v1/lab/results/41` is listed under the title "Premium API Access" and returns an x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0.02 USD given 6 decimals). Payment is made via the `exact` scheme to a specified wallet address. The endpoint accepts HTTP POST requests and returns `application/json` responses. No API keys or rate limits are advertised; access is gated entirely by per-request micropayment.
Documentation is minimal — the crawled site pages beyond the landing page only show a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The endpoint is live (402 challenge confirmed), but the actual functionality behind `/api/v1/lab/results/41` is unclear since it doesn't map to any of the publicly listed API categories on the homepage. Users should expect to experiment to discover the request format and response structure.
Capabilities
Use cases
- —Accessing data analytics and reports via per-request micropayments
- —Running AI inference (sentiment, summarization, classification, embeddings) without subscriptions
- —Fetching real-time crypto and finance data with no API key required
- —Using utility services like geocoding and validation on a pay-as-you-go basis
Fit
Best for
- —Developers who want zero-commitment, pay-per-use API access
- —Agent workflows that can settle USDC micropayments on Base
- —Prototyping and low-volume use cases where subscription APIs are overkill
Not for
- —High-volume production workloads needing SLAs and guaranteed uptime
- —Users who need detailed API documentation and request/response schemas before integrating
- —Teams that cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/lab/results/41 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Example
Request
{
"url": "https://lowpaymentfee.com/api/v1/lab/results/41",
"body": {},
"method": "POST",
"headers": {
"X-PAYMENT": "<x402-payment-token>",
"Content-Type": "application/json"
}
}Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming pricing and payment details. However, there is no OpenAPI spec, no documentation for request/response schemas, no examples, and the specific endpoint path (/api/v1/lab/results/41) does not correspond to any publicly listed API on the site. Functionality is essentially unknown.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The path /api/v1/lab/results/41 is not listed among the site's publicly advertised APIs — its purpose is unclear
- —All non-landing crawled pages returned only 'Connect wallet' with no useful content
- —No request body schema or response examples are documented anywhere
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/lab/results/41
- —Site offers endpoints in Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com