Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, no rate limits, and no commitments required. The x402 protocol handles payment inline: callers attach an X-PAYMENT header with a signed USDC payment, and the endpoint processes the request upon verification.
The specific endpoint at `/api/v1/transactions/76` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader platform advertises categories including metrics, reports, data export, insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, documentation beyond the landing page is essentially empty (pages like /docs, /pricing, and /README only show a "Connect wallet" prompt), so the actual functionality behind each endpoint is unverified. The specific behavior of the `/api/v1/transactions/76` endpoint is not documented beyond its title.
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 analytics, AI, finance, or utility endpoints without subscriptions
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents with x402-compatible wallets on Base
- —Users who prefer crypto micropayments over API key management
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/76 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming pricing and payment details. However, there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality of this specific endpoint (/api/v1/transactions/76) is completely undocumented. The docs, pricing, and README pages are all blank beyond a wallet-connect prompt.
Warnings
- —No documentation available — /docs, /pricing, and /README pages are empty (only show 'Connect wallet')
- —No OpenAPI or schema describing request parameters or response format for this endpoint
- —The specific purpose of /api/v1/transactions/76 ('Premium API Access') is not explained anywhere
- —Functionality of advertised endpoints (AI, analytics, finance, etc.) is unverified
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/76
- —Payment address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with 300-second timeouthttps://lowpaymentfee.com/api/v1/transactions/76
- —Platform advertises categories: Data & Analytics, AI & Machine Learning, Finance & Web3, Infrastructurehttps://lowpaymentfee.com