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/94` is labeled "Premium API Access" and requires a POST request with an x402 payment header. The maximum amount required per call is 20,000 base units of USDC (0x8335…), which equals $0.02 given USDC's 6 decimals. No API keys, rate limits, or upfront commitments are needed — each request is paid individually via an on-chain micropayment.
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 listed endpoints are priced at $0.02 per request. However, the specific endpoint probed here (`/api/v1/payments/94`) does not clearly map to any of those named services — its description is simply "Premium API Access" with no further documentation on what data or functionality it returns.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the endpoint actually returns. The endpoint is confirmed live (returns a valid 402 challenge), but without knowing what it does beyond the generic label, agents should treat this as an opaque paid endpoint.
Capabilities
Use cases
- —Paying per-call for API access without subscriptions or API keys
- —Integrating x402-compatible agents with a low-cost paid endpoint
- —Testing x402 protocol payment flows on Base network
Fit
Best for
- —Agents that support x402 payment protocol on Base
- —Developers exploring pay-per-request API models with crypto micropayments
- —Low-volume consumers who want no-commitment API access
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-network USDC wallet
Quick start
# The endpoint requires an X-PAYMENT header with a valid x402 payment proof.
# Using curl (you need an x402-compatible client to generate the header):
curl -X POST https://lowpaymentfee.com/api/v1/payments/94 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge, but there is zero documentation on what the endpoint actually does or returns. No OpenAPI spec, no request/response examples, and the docs pages are empty. The 'Premium API Access' label is completely generic.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content.
- —The endpoint path '/api/v1/payments/94' does not match any of the named API categories on the landing page; its actual functionality is unknown.
- —No request body schema or response schema is documented anywhere.
- —No OpenAPI or machine-readable spec is available.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/payments/94
- —All listed endpoints are priced at $0.02 per request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/94