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/210` 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 thin. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/transactions/210` endpoint actually returns. The endpoint is live (402 challenge confirmed), but without documentation it is unclear what data or functionality it provides beyond the generic "Premium API Access" label.
Capabilities
Use cases
- —Accessing premium data or transaction information via a single micropayment per request
- —Integrating pay-as-you-go API calls into agent workflows without managing API keys
- —Testing x402 protocol payment flows on the Base network
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-per-call API access
- —Low-volume consumers who want no subscription commitments
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone requiring guaranteed SLAs or support
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/210 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no request/response examples, and all documentation pages render only 'Connect wallet' with no content. The purpose of this specific endpoint (/api/v1/transactions/210) is entirely unclear beyond the generic label.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific function of /api/v1/transactions/210 is undocumented; 'Premium API Access' is a generic label
- —No request or response examples available anywhere in crawled content
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/210
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/210