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/354` 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 — 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.
This particular endpoint (`/api/v1/transactions/354`) is labeled "Premium API Access" but its actual functionality is not documented beyond that label. The crawled docs, pricing, API, and README pages all rendered only a "Connect wallet" prompt with no additional content. Without further documentation or an OpenAPI schema, the exact request format and response structure for this endpoint remain unknown.
Capabilities
Use cases
- —Programmatic access to premium API services paid per-call with USDC on Base
- —Agent-driven workflows that need keyless, on-demand API access
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously
- —Users already holding USDC on the Base network
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Anyone without USDC on Base or an x402-compatible payment client
- —High-volume consumers who need bulk/subscription pricing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/354 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and network. However, there is no OpenAPI schema, no documentation beyond a landing page listing, no request/response examples, and the actual functionality behind 'Premium API Access' at /api/v1/transactions/354 is entirely undocumented. The docs, pricing, API, and README pages all render only a wallet-connect prompt.
Warnings
- —The exact functionality of /api/v1/transactions/354 ('Premium API Access') is not documented anywhere in the crawled material.
- —All documentation pages (docs, pricing, API, README) returned only 'Connect wallet' with no usable content.
- —No OpenAPI schema or request/response examples are available.
- —The endpoint name 'transactions/354' suggests a resource-specific path but its purpose is unclear.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base network.https://lowpaymentfee.com/api/v1/transactions/354
- —The platform lists all endpoints at $0.02/request with no API keys, no rate limits, and instant access.https://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/354
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com