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/238` 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. No API keys or rate limits are required; callers simply attach an x402 payment header to each request.
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.
Documentation is extremely sparse — 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/238` endpoint actually returns. The endpoint is live and responds with a valid x402 challenge, but without documentation it is unclear what data or functionality this specific resource provides.
Capabilities
Use cases
- —Accessing premium data or transaction information via a single USDC micropayment
- —Integrating pay-per-call APIs without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand API access settled in USDC on Base
Fit
Best for
- —Developers who want keyless, pay-as-you-go API access
- —AI agents with x402-compatible payment capabilities
- —Users already holding USDC on the Base network
Not for
- —Users who need detailed API documentation or schemas before integrating
- —Applications requiring free or subscription-based access models
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/238 \
-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 it accepts USDC on Base at $0.02/request. However, there is no OpenAPI schema, no documentation beyond a wallet-connect prompt, no request/response examples, and no description of what this specific endpoint actually returns. The listing is effectively a stub.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request parameters or response format
- —The purpose of /api/v1/transactions/238 ('Premium API Access') is completely undocumented
- —Cannot verify what data or functionality this endpoint provides
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on the Base networkhttps://lowpaymentfee.com/api/v1/transactions/238
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/238
- —API categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com