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/payments/289` is listed as "Premium API Access" and returns a standard x402 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) per call. No API keys or accounts are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises multiple API categories including 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 uniformly priced at $0.02 per request. The platform claims no rate limits, no minimums, and instant access.
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/payments/289` endpoint actually returns. The endpoint is confirmed live (402 challenge captured), but the actual functionality behind this specific path is unclear.
Capabilities
Use cases
- —Accessing premium API endpoints without creating an account or managing API keys
- —Making one-off API calls with per-request USDC micropayments on Base
- —Agent-driven workflows that need frictionless, wallet-based API access
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —AI agents with Base network USDC wallets needing on-demand API calls
- —Prototyping and low-volume usage where subscription plans are overkill
Not for
- —High-volume production workloads needing SLAs and guaranteed uptime
- —Users without a Base network wallet or USDC holdings
- —Anyone needing detailed API documentation or schema guarantees before integration
Quick start
# The endpoint returns HTTP 402 with an x402 challenge.
# Attach a valid X-PAYMENT header (x402 protocol) to complete the call.
curl -X POST https://lowpaymentfee.com/api/v1/payments/289 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality of this specific endpoint path (/api/v1/payments/289) is entirely undocumented. The docs and related pages are empty beyond a wallet-connect prompt.
Warnings
- —No OpenAPI schema or endpoint documentation available
- —The /docs, /pricing, /api, and /README pages all render only 'Connect wallet' with no usable content
- —The specific functionality of /api/v1/payments/289 ('Premium API Access') is not described anywhere
- —No request body schema or response schema is documented
- —Cannot verify what data or service this endpoint actually provides
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/payments/289
- —The platform advertises $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs