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/349` 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.
However, documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/transactions/349` endpoint actually returns. The endpoint is live and responds with a valid x402 challenge, but without documentation it is unclear what data or functionality this specific resource provides.
Capabilities
Use cases
- —Accessing premium API data without requiring 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 zero-signup, pay-per-use 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
- —High-volume consumers who need bulk pricing or subscription plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/349 \
-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 virtually no documentation: no OpenAPI schema, no request/response examples, and the docs/pricing/README pages are empty beyond a wallet-connect prompt. It is unclear what this specific endpoint actually does or returns. The listing is effectively a stub.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or request/response schema provided; impossible to know what this endpoint returns.
- —The endpoint path '/api/v1/transactions/349' with description 'Premium API Access' is generic and does not clarify the resource's purpose.
- —All non-homepage crawled pages returned no meaningful content.
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/349
- —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 Basehttps://lowpaymentfee.com/api/v1/transactions/349