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 `/api/v1/payments/358` is listed as "Premium API Access" and costs $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys, rate limits, or upfront commitments are required — each request is paid for individually via an X-PAYMENT header.
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 and settle on the Base network using USDC.
However, the specific endpoint probed here (`/api/v1/payments/358`) does not clearly map to any of the named API categories on the landing page. Its description is simply "Premium API Access" with no further documentation on what data or functionality it returns. The docs, pricing, and API pages all render only a "Connect wallet" prompt with no additional content, so there is no schema documentation, example requests, or example responses available.
Capabilities
Use cases
- —Accessing premium API endpoints with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers wanting to experiment with x402 payment protocol
- —Agents that need instant, keyless API access settled in USDC
- —Low-volume or sporadic API consumers who prefer per-call pricing over subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/358 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge), but there is no documentation, no OpenAPI schema, no example requests or responses, and the endpoint's actual functionality is unclear. The docs/pricing/API pages are all empty beyond a wallet connect prompt.
Warnings
- —The endpoint path /api/v1/payments/358 does not correspond to any documented API on the landing page — its actual functionality is unknown.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no useful content.
- —No OpenAPI spec, input schema, or output schema is available — callers cannot know what to send or expect back.
- —This listing may be a generic or placeholder endpoint rather than a fully functional API.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 USDC base units on Base networkhttps://lowpaymentfee.com/api/v1/payments/358
- —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 is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/358