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 pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/219` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader 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 utilities (geocoding, validation, conversion, generation). However, documentation pages beyond the landing page are essentially empty (showing only "Connect wallet"), so the actual functionality, request schemas, and response formats for any of these endpoints are undocumented. It is unclear what data or computation this specific `/transactions/219` endpoint actually provides.
Capabilities
Use cases
- —Accessing on-demand API services without creating accounts or managing API keys
- —Making micropayment-gated API calls settled in USDC on Base
- —Programmatic agent-to-service transactions using x402 protocol
Fit
Best for
- —Developers wanting zero-friction API access without signup
- —Agents that can settle x402 payments on Base in USDC
- —Use cases requiring low-cost per-request pricing with no commitments
Not for
- —Users who need detailed API documentation and request/response schemas before integrating
- —High-volume consumers who need bulk pricing or subscription discounts
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/219 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming pricing and payment details. However, there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what the endpoint actually does beyond the generic label "Premium API Access." All doc pages are empty stubs.
Warnings
- —No documentation available — all doc/pricing/API pages show only 'Connect wallet' with no content
- —The specific purpose of /api/v1/transactions/219 ('Premium API Access') is completely undocumented
- —No request body schema or response schema is provided anywhere
- —Cannot verify what data or computation any endpoint actually returns
Citations
- —All endpoints priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (6 decimals = $0.02) on Basehttps://lowpaymentfee.com/api/v1/transactions/219
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/219