Pay-per-call premium API endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. This specific endpoint (`/api/endpoint-19`) is listed as "Premium API Access" and accepts USDC payments on Base. The x402 challenge confirms the endpoint is live and requires a maximum of 20,000 base units of USDC (0.02 USD) per request. No API keys or rate limits are advertised — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform advertises endpoints across several 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 listed endpoints share the same $0.02/request pricing. However, this particular endpoint path (`/api/endpoint-19`) does not correspond to any of the named endpoints on the site's landing page, so its exact functionality is unclear.
The endpoint responds to POST requests and returns `application/json`. Payment is sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base. Documentation pages (/docs, /pricing, /README) returned only a "Connect wallet" prompt with no substantive content, so detailed request/response schemas are unavailable.
Capabilities
Use cases
- —Programmatic access to a premium API without traditional API key management
- —Agent-driven workflows that need to pay per call using USDC on Base
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment flows
- —AI agents with Base USDC wallets needing on-demand API access
- —Low-volume, pay-as-you-go API consumption without subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume use cases where $0.02/request adds up significantly
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-19 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but the specific functionality of /api/endpoint-19 is unknown — it doesn't match any named endpoint on the landing page. Documentation pages are empty stubs. No request/response schema is available.
Warnings
- —The path /api/endpoint-19 does not match any of the named endpoints listed on the provider's landing page; its actual functionality is unknown.
- —All documentation pages (/docs, /pricing, /README, /api) returned only 'Connect wallet' with no substantive content.
- —No OpenAPI spec, request schema, or response schema is available — callers cannot know what to send or expect back.
- —The provider site appears to be a generic x402 demo or placeholder; endpoint reliability and data quality are unverified.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base, equating to $0.02 per request.https://lowpaymentfee.com/api/endpoint-19
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —USDC contract address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 and payTo is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3.https://lowpaymentfee.com/api/endpoint-19
- —Documentation pages (/docs, /pricing, /README) returned only a 'Connect wallet' prompt.https://lowpaymentfee.com/docs