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 a pay-per-call API marketplace that uses the x402 payment protocol to gate access to a variety of endpoints. The platform accepts USDC payments on the Base network, with most endpoints priced at $0.02 per request. No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/lab/results/25` is listed as "Premium API Access" and its x402 challenge advertises a maximum cost of 20,000 base units of USDC (i.e., $0.02, since USDC uses 6 decimals). The endpoint accepts POST requests and returns `application/json`. However, the exact data returned by this particular path (`/lab/results/25`) is not documented on the site — the landing page catalogs categories like Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure utilities, but does not mention a "lab/results" path. It is unclear whether this endpoint returns lab test results, experimental data, or something else entirely.
The broader platform offers endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. All endpoints settle via USDC on Base to the same payTo address.
Capabilities
Use cases
- —Accessing gated API data with per-request USDC micropayments on Base
- —Integrating pay-as-you-go endpoints into agent workflows without API key management
- —Retrieving lab or experimental results behind a paywall
Fit
Best for
- —Developers wanting zero-commitment, pay-per-call 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 free or ad-supported API access
- —Applications requiring high-throughput bulk requests where per-call pricing is inefficient
- —Anyone needing detailed documentation or guaranteed SLAs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/lab/results/25 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge) and pricing is clear ($0.02 USDC on Base). However, the specific /lab/results/25 path is not documented anywhere on the site, there is no OpenAPI schema, no request/response examples, and the crawled docs pages (api, pricing, README) returned only 'Connect wallet' with no useful content. The purpose of this particular endpoint is unknown.
Warnings
- —The /api/v1/lab/results/25 path is not listed on the provider's landing page — its purpose and response format are undocumented.
- —No OpenAPI spec, request schema, or response examples are available for any endpoint on this platform.
- —The /pricing, /api, and /README pages returned no meaningful content (only 'Connect wallet'), suggesting documentation is minimal or requires wallet connection to view.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base, equating to $0.02 per request.https://lowpaymentfee.com/api/v1/lab/results/25
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 is used for payment on Base.https://lowpaymentfee.com/api/v1/lab/results/25
- —The site lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com