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 accessible via the x402 payment protocol on the Base network. This specific endpoint (`/api/endpoint-54`) is listed as "Premium API Access" and accepts USDC payments on Base. The x402 challenge confirms the endpoint is live and charges a maximum of 20,000 base units of USDC (i.e., $0.02 per request, since USDC uses 6 decimals). Payment is settled on-chain to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3`.
The provider's landing page advertises a broad suite of endpoints spanning 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 priced at $0.02 per request. However, this particular endpoint path (`/api/endpoint-54`) does not correspond to any of the named endpoints on the landing page, and no documentation, input schema, or response schema is available for it. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional content.
Without documentation or an output schema describing what this endpoint actually returns, its concrete functionality is unknown. The x402 challenge confirms it is a POST endpoint returning `application/json`, but the actual data or service behind it is unspecified.
Capabilities
Use cases
- —Programmatic access to a premium API service with per-call USDC micropayments
- —Agent-driven workflows that need keyless, on-demand API access on Base
- —Exploring x402 payment protocol integrations
Fit
Best for
- —Developers experimenting with x402 payment flows
- —Agents that can settle USDC on Base for per-call API access
- —Low-volume, pay-as-you-go API consumption without subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume use cases where $0.02/request adds up significantly
- —Anyone unable to transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-54 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is zero documentation for this specific endpoint path. No input/output schema, no examples, and the docs pages are empty. The endpoint path does not match any named service on the landing page, making its actual functionality unknown.
Warnings
- —Endpoint path /api/endpoint-54 does not match any documented endpoint on the provider's landing page
- —No input or output schema available — actual functionality is unknown
- —All documentation pages (docs, API, pricing, README) render only a 'Connect wallet' prompt with no content
- —No OpenAPI spec or AI plugin manifest found
Citations
- —The x402 challenge returns 402 with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/endpoint-54
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/endpoint-54
- —Landing page lists endpoints at $0.02/request with no API keys, no rate limitshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages show only 'Connect wallet'https://lowpaymentfee.com/docs