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 at `/api/v1/transactions/257` is labeled "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 $0.02 per request.
This particular endpoint (`/api/v1/transactions/257`) is confirmed live, returning a valid x402 challenge via POST. However, there is no documentation describing what this specific endpoint returns — the crawled docs, pricing, and README pages all rendered only a "Connect wallet" prompt with no substantive content. Without an OpenAPI schema or example responses, the actual functionality of this endpoint remains unclear.
Capabilities
Use cases
- —Accessing premium API data without traditional API key registration
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
Fit
Best for
- —Developers who want to avoid API key management and subscriptions
- —AI agents that can attach x402 payment headers autonomously
- —Users already holding USDC on the Base network
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/257 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no documentation, no OpenAPI schema, no example request/response, and the actual functionality of '/api/v1/transactions/257' is entirely undescribed. The docs, pricing, and README pages all render only 'Connect wallet' with no content. This is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, and README pages all show only 'Connect wallet' with no substantive content.
- —The specific functionality of /api/v1/transactions/257 ('Premium API Access') is not described anywhere in the crawled material.
- —No OpenAPI schema or example request/response is available.
- —The platform lists many endpoint categories (AI, analytics, finance, infrastructure) but none have documented schemas or verifiable functionality.
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/257
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 is USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/257
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com