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 at `/api/v1/payments/22` 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 subscriptions 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/22` endpoint is not documented beyond its "Premium API Access" label, and the crawled docs/pricing/README pages returned only a wallet-connect prompt with no additional content.
The endpoint is live, returning a valid x402 402 challenge with scheme "exact" on the Base network, paying to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the USDC contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`. The timeout is 300 seconds. No OpenAPI schema, request/response examples, or detailed documentation were found for this specific endpoint.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, on-demand API access
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers or agents wanting frictionless pay-per-use API access without subscriptions
- —x402-compatible wallets and agents on the Base network
- —Low-cost experimentation with crypto-settled API calls
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Users without access to USDC on the Base network
Quick start
# The endpoint requires an x402 payment header with USDC on Base.
# Using curl (you need an x402-compatible client to generate X-PAYMENT):
curl -X POST https://lowpaymentfee.com/api/v1/payments/22 \
-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 request/response examples, and the docs pages are empty beyond a wallet-connect prompt. The actual functionality behind 'Premium API Access' at /api/v1/payments/22 is undocumented, making this effectively a stub listing.
Warnings
- —The specific functionality of /api/v1/payments/22 ('Premium API Access') is not documented — it is unclear what data or service it returns.
- —All documentation, pricing, and README pages returned only a 'Connect wallet' prompt with no substantive content.
- —No OpenAPI spec, request schema, or response schema is available.
- —The platform lists many API categories (AI, finance, data, etc.) but none have documented request/response formats.
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/payments/22
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/22
- —All endpoints are priced at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com