Pay-per-call API platform on Base (USDC) via x402 — $0.02/request, no API keys required.
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 at `/api/v1/payments/146` is labeled "Premium API Access" and charges up to 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals) per call. No API keys, rate limits, or upfront commitments are required — each request is individually settled on-chain.
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 functionality behind the `/api/v1/payments/146` endpoint is not documented beyond its "Premium API Access" label. There is no OpenAPI schema, no request/response examples, and the crawled docs, pricing, and API pages all returned only a "Connect wallet" prompt with no additional content. The endpoint is confirmed live (returns a valid x402 402 challenge), but what data or service it actually returns upon successful payment is unknown.
Capabilities
Use cases
- —Paying per-request for API access without managing API keys or subscriptions
- —Integrating on-chain USDC micropayments into agent workflows
- —Accessing various utility, AI, or data endpoints with instant crypto settlement
Fit
Best for
- —Developers or agents who want zero-signup, pay-as-you-go API access
- —Use cases requiring on-chain payment receipts for each API call
- —Low-volume or sporadic API consumers who want to avoid subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —High-volume consumers who would benefit from bulk pricing or rate-limited plans
- —Anyone without access to USDC on the Base network
Quick start
# The endpoint returns HTTP 402 with an x402 challenge.
# Use an x402-compatible client to pay and access:
curl -X POST https://lowpaymentfee.com/api/v1/payments/146 \
-H 'Content-Type: application/json'
# Returns 402 with accepts[].maxAmountRequired = 20000 (USDC, 6 decimals = $0.02)
# Attach a valid X-PAYMENT header to complete the transaction.Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge and clear pricing ($0.02 USDC on Base). However, there is no documentation of what the endpoint actually returns, no OpenAPI schema, no request/response examples, and the docs pages are empty. The 'Premium API Access' label is generic and uninformative.
Warnings
- —No documentation available — all doc/pricing/API pages return only 'Connect wallet' with no content
- —The specific functionality of /api/v1/payments/146 is completely undocumented
- —No OpenAPI schema or request/response examples provided
- —Cannot verify what data or service is delivered after successful payment
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 USDC base units on Base networkhttps://lowpaymentfee.com/api/v1/payments/146
- —The platform lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $0.02/request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/payments/146