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/23` is listed as "Premium API Access" and returns JSON content upon payment. The x402 challenge advertises a max amount of 20,000 base units of USDC (0x8335…), which equals $0.02 per request (USDC uses 6 decimals). No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform offers endpoints 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 uniformly priced at $0.02 per request.
This particular endpoint (`/api/v1/lab/results/23`) appears to be a lab/results resource, but no documentation describes what data it returns beyond the generic "Premium API Access" label. The endpoint is live and responds with a proper 402 challenge on POST. There is no OpenAPI schema, no detailed documentation, and no example responses available from the crawled material.
Capabilities
Use cases
- —Accessing premium data or lab results without subscription or API key management
- —Agent-driven workflows that need on-demand paid API calls settled in crypto
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 micropayment protocols
- —AI agents that need keyless, pay-per-use API access on Base
- —Low-volume consumers who want no-commitment API access at $0.02/call
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/lab/results/23 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no OpenAPI schema, no documentation of request/response formats, and no description of what '/api/v1/lab/results/23' actually returns. The listing is essentially a stub with confirmed liveness and pricing.
Warnings
- —No documentation available for what this specific endpoint returns — 'Premium API Access' is the only description
- —No OpenAPI or JSON schema provided for request or response bodies
- —No example responses available; actual payload content is unknown
- —The '/api/v1/lab/results/23' path suggests a specific resource ID (23) but no context is given for what 'lab results' means in this domain
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/lab/results/23
- —All endpoints on lowpaymentfee.com are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/lab/results/23
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com