Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/transactions/146` is listed as "Premium API Access" and returns a 402 challenge requiring payment of up to 20,000 base units of USDC (i.e., $0.02) per call. No API keys or rate limits are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises multiple API categories including 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.
However, the specific functionality behind `/api/v1/transactions/146` is not documented beyond the label "Premium API Access." There is no OpenAPI schema, no request/response examples, and the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further content. The endpoint is confirmed live (402 challenge captured), but what data or service it actually returns upon successful payment is unknown.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Testing x402 protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless API access with crypto micropayments
- —Low-volume, on-demand API consumption without subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume use cases where $0.02/request adds up significantly
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/146 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 x402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no documentation of what the endpoint actually returns, no OpenAPI schema, no request/response examples, and the docs pages are empty. The specific purpose of '/api/v1/transactions/146' is entirely opaque beyond the generic label 'Premium API Access.'
Warnings
- —No documentation available — docs, pricing, and API pages only show 'Connect wallet' with no content
- —The specific functionality of /api/v1/transactions/146 is undocumented; 'Premium API Access' is the only description
- —No OpenAPI schema or request/response examples provided
- —No way to verify what data or service is returned after payment without actually paying
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/146
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/146