Pay-per-call API platform on Base network via x402 — $0.02/request, no API keys required.
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/70` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
The broader platform offers endpoints across four 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 the same $0.02/request price point.
However, 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 the `/api/v1/transactions/70` endpoint actually returns or what input it expects beyond a POST request. The endpoint is live and responding with a valid x402 challenge, but without documentation it is unclear what data or functionality it provides.
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 with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless API access with crypto micropayments
- —Low-volume, on-demand API consumption without subscriptions
Not for
- —Production workloads requiring well-documented, stable APIs with SLAs
- —Users without a Base network USDC wallet
- —High-volume use cases where $0.02/request adds up significantly
Quick start
# The endpoint requires an x402 payment header with USDC on Base.
# Using curl with the x402 protocol:
curl -X POST https://lowpaymentfee.com/api/v1/transactions/70 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <your-x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no OpenAPI schema, no documentation beyond a landing page listing, no request/response examples, and no explanation of what this specific endpoint actually does. The docs pages are empty. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition for any endpoint
- —The purpose and expected input/output of /api/v1/transactions/70 is completely undocumented
- —Cannot verify what data or service is actually returned after payment
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/70
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —The platform advertises no API keys, no rate limits, instant access, and Base network settlementhttps://lowpaymentfee.com
- —The USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/70