Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. It is one of many endpoints offered by the provider, which spans categories including data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, no rate limits, and no commitments required.
The specific endpoint `/api/v1/payments/340` returns a valid x402 challenge (HTTP 402) requesting payment of up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the `exact` scheme to wallet `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout. The endpoint accepts POST requests and returns `application/json`.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what this particular endpoint actually returns or what input it expects beyond a POST body. The provider's landing page lists many other endpoints (metrics, reports, sentiment analysis, summarization, price feeds, geocoding, etc.) but does not clarify what `/api/v1/payments/340` specifically does. Treat this as a stub listing until more documentation becomes available.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Testing x402 payment protocol integrations
Fit
Best for
- —Developers experimenting with x402 pay-per-call patterns
- —Agents that need keyless, on-demand API access settled in USDC on Base
- —Low-commitment API usage with no minimums or subscriptions
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —High-volume use cases where per-request crypto payments add unacceptable latency
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/340 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what this specific endpoint does. The docs pages are empty. This is effectively a stub.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or schema describing request parameters or response format for /api/v1/payments/340.
- —The purpose of this specific endpoint (/api/v1/payments/340) is unclear; 'Premium API Access' is a generic label.
- —No request or response examples available anywhere in the crawl.
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02.https://lowpaymentfee.com/api/v1/payments/340
- —Provider offers endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categories.https://lowpaymentfee.com