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/27` is labeled "Premium API Access" and charges up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
The broader platform offers 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 endpoints are listed at the same $0.02/request price point.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed description of what the `/api/v1/payments/27` endpoint specifically returns. The x402 challenge confirms the endpoint is live and accepts POST requests, but the actual functionality behind this particular path is unclear from available materials.
Capabilities
Use cases
- —Agents that need on-demand API access without pre-registration or API key management
- —Programmatic access to data, AI, finance, or utility endpoints with per-call USDC micropayments
- —Testing x402 protocol integrations with a low-cost live endpoint
Fit
Best for
- —Developers exploring x402 payment protocol integrations
- —AI agents needing keyless, pay-as-you-go API access
- —Low-volume consumers who want no subscription commitments
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/27 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge confirms the endpoint is live and pricing is clear ($0.02 USDC on Base). However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and the specific functionality of /api/v1/payments/27 is not described anywhere. This is effectively a stub listing.
Warnings
- —No documentation available — all doc/pricing/API/README pages render only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific purpose of /api/v1/payments/27 ('Premium API Access') is not explained anywhere
- —No request or response examples available to verify actual functionality
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base network, maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/payments/27
- —Platform lists endpoints at $0.02/request across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/27