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/276` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) 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 priced at $0.02 per request.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/transactions/276` endpoint actually returns. The endpoint is live (402 challenge confirmed), but without documentation it is unclear what data or functionality this specific transaction endpoint provides.
Capabilities
Use cases
- —Accessing premium API data without subscription or API key management
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven workflows that need instant, keyless API access with crypto payment
Fit
Best for
- —Developers who want pay-per-use API access without sign-up
- —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 schemas before integrating
- —Anyone without USDC on Base or unfamiliar with x402 payment flows
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/276 \
-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 zero documentation on what the endpoint actually does or returns. No OpenAPI schema, no request/response examples, and all doc pages render only 'Connect wallet'. The specific endpoint path (/api/v1/transactions/276) is not listed on the homepage, making its purpose unclear.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all show only 'Connect wallet'
- —No OpenAPI or output schema describing request parameters or response format
- —The specific endpoint /api/v1/transactions/276 is not listed among the advertised APIs on the homepage
- —Purpose of this endpoint is entirely unclear — 'Premium API Access' is a generic label
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/276
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/276
- —Documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet'https://lowpaymentfee.com/docs