Pay-per-request API platform on Base network via x402 — $0.02/call in USDC.
What it does
lowpaymentfee.com is an x402-enabled API marketplace that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/products/52` is listed as "Premium API Access" and returns `application/json` via POST. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, which has 6 decimals), equating to $0.02 per call. The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises endpoints for 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. Documentation pages exist but appear to require a wallet connection to view, so detailed request/response schemas are not publicly available. The endpoint is confirmed live (402 challenge captured successfully).
Capabilities
Use cases
- —Agents needing on-demand API access without pre-registration or API keys
- —Programmatic access to data, AI, finance, or utility endpoints with per-call USDC micropayments
- —Testing x402 payment protocol integrations on Base network
Fit
Best for
- —AI agents that can settle x402 payments in USDC on Base
- —Developers exploring pay-per-request API models without subscriptions
- —Low-volume or bursty workloads where flat-rate pricing is wasteful
Not for
- —High-volume production workloads where $0.02/request adds up quickly
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Callers without access to USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/52 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and the x402 challenge is well-formed with clear pricing. However, there is no OpenAPI spec, no request/response schema documentation, and the docs pages all just show 'Connect wallet' with no actual content. The purpose of this specific '/api/v1/products/52' endpoint is unclear beyond the generic label 'Premium API Access'.
Warnings
- —No OpenAPI or request/response schema available — input format for this endpoint is unknown
- —Documentation pages require wallet connection and contain no visible content
- —The specific purpose of /api/v1/products/52 ('Premium API Access') is not described anywhere — it may be a generic or placeholder endpoint
- —Cannot verify what data or service this endpoint actually returns
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 returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) equaling $0.02https://lowpaymentfee.com/api/v1/products/52
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com