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/38` is listed as "Premium API Access" and costs $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys, rate limits, or subscriptions are required — each request is paid individually via an X-PAYMENT header containing a signed payment.
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 listed at the same $0.02/request price point.
However, the specific endpoint probed (`/api/v1/transactions/38`) does not clearly map to any of the advertised API categories on the landing page. Its description is simply "Premium API Access" with no further documentation on what data or functionality it returns. The docs, pricing, and API pages all returned only a "Connect wallet" prompt with no substantive content. Without documentation or example responses, the actual behavior of this endpoint is unknown.
Capabilities
Use cases
- —Programmatic access to a pay-per-request API without needing API keys or subscriptions
- —Agent-driven workflows that settle per-call costs in USDC on Base
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers exploring x402 payment protocol integrations
- —Agents that need keyless, pay-as-you-go API access
- —Low-cost per-request API consumption settled on-chain
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Anyone without a Base-network USDC wallet
- —Production workloads requiring well-documented response schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/38 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge), but there is no documentation, no OpenAPI schema, no example responses, and the endpoint path '/api/v1/transactions/38' doesn't match any advertised API on the landing page. The docs/pricing/API pages are all empty beyond a wallet-connect prompt. Effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, and API pages all return only 'Connect wallet' with no content
- —The endpoint path /api/v1/transactions/38 does not correspond to any of the advertised API categories on the landing page
- —No response schema or example output is available; actual endpoint behavior is unknown
- —No OpenAPI spec or ai-plugin manifest found
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 in USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/38
- —All listed APIs are priced at $0.02/request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform advertises categories including Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com