Pay-per-call premium API on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints settled via the x402 protocol on the Base network using USDC. This specific endpoint (`/api/endpoint-80`) is listed as "Premium API Access" and accepts POST requests. Payment is 0.02 USDC per call (maxAmountRequired of 20,000 base units with 6-decimal USDC). No API keys, rate limits, or upfront commitments are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform advertises endpoints across four categories: 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 are priced at $0.02 per request. However, this listing covers `/api/endpoint-80` specifically, which is described only as "Premium API Access" without further detail on what data or functionality it returns.
The endpoint is live and returns a well-formed x402 challenge (version 1, scheme "exact") paying to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` in USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base. The response MIME type is `application/json`. Documentation beyond the landing page is essentially empty (all sub-pages just show "Connect wallet"), so the actual request/response schema for this endpoint is unknown.
Capabilities
Use cases
- —Programmatic access to a premium API endpoint without needing API key registration
- —Agent-driven workflows that settle per-call costs in USDC on Base
- —Testing x402 payment flows against a low-cost live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —AI agents that need keyless, pay-as-you-go API access
- —Users who want to avoid subscription commitments for occasional API calls
Not for
- —Users who need detailed documentation or well-defined request/response schemas before integrating
- —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/endpoint-80 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but the actual functionality behind '/api/endpoint-80' is undocumented. No request/response schema, no examples, and all documentation pages are blank ('Connect wallet'). The listing is effectively a stub with only pricing and protocol details confirmed.
Warnings
- —The specific functionality of /api/endpoint-80 is completely undocumented — 'Premium API Access' is the only description available.
- —All documentation pages (/docs, /api, /pricing, /README) return only 'Connect wallet' with no actual content.
- —No request body schema or response schema is provided, so callers cannot know what to send or what to expect back.
- —This endpoint path (/api/endpoint-80) does not match any of the named endpoints listed on the landing page, raising questions about what it actually does.
Citations
- —Endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/endpoint-80
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/endpoint-80
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com