Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
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/transactions/271` is listed as "Premium API Access" and returns a 402 challenge requiring payment of up to 20,000 base units of USDC (i.e., $0.02) per call. No API keys or rate limits are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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 priced at $0.02 per request.
However, the specific endpoint probed here (`/api/v1/transactions/271`) does not clearly map to any of the documented API categories. Its description is simply "Premium API Access" with no further documentation on what data or functionality it returns. The docs, pricing, and README pages all rendered only a "Connect wallet" prompt with no substantive content. Without an OpenAPI schema, example responses, or detailed documentation, the actual behavior of this endpoint remains unclear.
Capabilities
Use cases
- —Programmatic access to premium API endpoints without managing API keys or subscriptions
- —Agent-driven workflows that need to pay per call using USDC on Base
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers exploring x402 pay-per-call patterns
- —AI agents that need keyless, on-demand API access
- —Low-volume or sporadic API consumers who prefer pay-as-you-go
Not for
- —Users needing well-documented, production-grade APIs with clear response schemas
- —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/transactions/271 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no example request/response, and the docs pages are empty. The specific endpoint '/api/v1/transactions/271' has no documented purpose beyond the generic label 'Premium API Access'. This is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, and README pages all show only 'Connect wallet' with no content.
- —The endpoint path '/api/v1/transactions/271' does not match any of the advertised API categories on the landing page; its actual functionality is unknown.
- —No OpenAPI schema or response examples are available; callers cannot know what this endpoint returns before paying.
- —No input schema documented — unclear what POST body (if any) is expected.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/271
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/271
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com