Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides pay-per-request API access using the x402 payment protocol, settling in USDC on the Base network. The specific endpoint `/api/v1/lab/results/5` is labeled "Premium API Access" and returns JSON responses upon payment. The x402 challenge confirms it is live and accepts exact-scheme payments with a max amount of 20,000 base units of USDC (i.e., $0.02 per request).
The broader lowpaymentfee.com platform advertises a suite of APIs across several 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 listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments required.
However, the specific endpoint `/api/v1/lab/results/5` does not clearly map to any of the advertised categories on the landing page. Its exact functionality — what "lab results" it returns — is undocumented. There is no OpenAPI schema, no request/response examples, and no detailed documentation available from the crawled pages. The payment mechanism is confirmed working, but the actual data returned is unknown.
Capabilities
Use cases
- —Accessing premium data endpoints without traditional API key registration
- —Making one-off API calls with instant USDC micropayments on Base
- —Agent-driven data retrieval with per-request crypto settlement
Fit
Best for
- —Developers who want keyless, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Anyone without a Base-compatible USDC wallet
- —High-volume use cases where per-request pricing may not be cost-effective compared to bulk plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/lab/results/5 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02/request in USDC on Base). However, the specific endpoint's purpose ("lab/results/5") is entirely undocumented — it doesn't appear in the site's advertised API list. No OpenAPI schema, no request/response examples, and no documentation pages rendered meaningful content. This is effectively a stub listing.
Warnings
- —The endpoint /api/v1/lab/results/5 is not listed among the advertised APIs on the landing page; its actual functionality is unknown.
- —No OpenAPI schema or request/response documentation is available.
- —The /api, /pricing, and /README pages returned only 'Connect wallet' with no useful content.
- —The exact data returned by this endpoint cannot be verified without making a paid request.
Citations
- —The x402 challenge returns 402 with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/lab/results/5
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/lab/results/5
- —All listed APIs priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Advertised API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com