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/358` is listed as "Premium API Access" and returns a 402 challenge requesting 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 — callers 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.
However, the specific endpoint being listed here (`/api/v1/transactions/358`) 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, request/response examples, or detailed documentation, the actual behavior of this endpoint remains unclear.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic access to transaction or premium data without subscription commitments
Fit
Best for
- —Developers wanting no-signup, pay-per-call API access
- —AI agents that can settle x402 payments autonomously
- —Users already holding USDC on Base network
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —Anyone without a Base-network USDC wallet
- —High-volume use cases where per-request pricing may add up
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/358 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, no documentation beyond a landing page listing, and the specific endpoint's purpose ("Premium API Access" at /transactions/358) is unexplained. Docs pages returned only 'Connect wallet' with no content.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The endpoint path /api/v1/transactions/358 does not match any documented API category on the site
- —All documentation pages (docs, pricing, README, api) returned only a 'Connect wallet' prompt with no substantive content
- —The actual response payload and expected request body are unknown
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/358
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —The platform advertises no API keys, no rate limits, instant access, and Base network settlementhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/358