Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are paid per-request at $0.02 each using USDC on the Base network, with no API keys, no rate limits, and no commitments required. The specific endpoint at `/api/v1/transactions/378` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) on Base.
The platform advertises 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 (geocoding, validation, conversion, generation). However, the crawled documentation pages (`/docs`, `/api`, `/pricing`, `/README`) all returned only a "Connect wallet" prompt with no substantive content, so there is no detailed documentation, request/response schemas, or usage examples available for any of these endpoints.
Without documentation or example payloads, it is unclear what input this specific `/api/v1/transactions/378` endpoint expects or what it returns. The x402 challenge confirms the endpoint is live and accepts POST requests settled in USDC on Base, but the actual functionality behind "Premium API Access" is not described anywhere in the crawled material.
Capabilities
Use cases
- —Paying per-call for API access without needing API keys or subscriptions
- —Integrating x402 payment protocol into agent workflows for on-demand data
- —Accessing various utility and data endpoints with USDC micropayments on Base
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost per-request billing without rate limits
Not for
- —Users who need detailed API documentation and schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/378 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is zero documentation, no request/response schemas, and no examples for any endpoint. The specific endpoint's purpose ('Premium API Access') is entirely opaque. All doc pages return only 'Connect wallet' with no content.
Warnings
- —No documentation available — all doc pages (/docs, /api, /pricing, /README) return only 'Connect wallet' with no content
- —No request or response schema provided for this endpoint
- —The purpose and functionality of /api/v1/transactions/378 ('Premium API Access') is undocumented and unclear
- —Cannot verify what data or service is actually delivered 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/378
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure endpointshttps://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) contain only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs