Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. Each call costs $0.02 in USDC on the Base network, settled via the x402 exact-payment scheme. No API keys, accounts, or rate limits are required — callers simply attach an X-PAYMENT header with a valid payment proof.
The specific endpoint at `/api/v1/payments/314` is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, which has 6 decimals), equating to $0.02 per call. Payment is directed 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. However, documentation pages (docs, pricing, README) returned only a "Connect wallet" prompt with no substantive content, so the actual behavior, input schemas, and response formats for these endpoints remain undocumented in the crawled material.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification, embeddings) without managing API keys
- —Fetching real-time crypto gas estimates or token price quotes with per-call payment
- —Geocoding or data validation as a utility service paid in USDC on Base
- —Exporting analytics data or generating reports on a pay-as-you-go basis
Fit
Best for
- —AI agents and bots that can settle x402 payments autonomously on Base
- —Developers who want zero-signup, zero-rate-limit API access
- —Micropayment use cases where $0.02/call is cost-effective
Not for
- —Users who need detailed API documentation or guaranteed SLAs — docs are currently empty
- —High-volume batch workloads where per-call crypto settlement overhead is impractical
- —Users without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/314 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no documentation of request/response formats, and all docs/pricing/README pages returned only 'Connect wallet' with no content. The actual functionality behind 'Premium API Access' at /payments/314 is unspecified. This is effectively a stub listing.
Warnings
- —Documentation pages (/docs, /pricing, /README, /api) all returned only 'Connect wallet' with no substantive content
- —No OpenAPI or schema available — request and response formats are unknown
- —The specific purpose of /api/v1/payments/314 ('Premium API Access') is not described anywhere; it may be a generic or placeholder endpoint
- —Cannot verify what data or service is actually returned upon successful payment
Citations
- —Platform advertises $0.02/request pricing 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 (USD Coin) on Base with 300-second timeouthttps://lowpaymentfee.com/api/v1/payments/314
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 (Base mainnet USDC with 6 decimals)https://lowpaymentfee.com/api/v1/payments/314
- —Available endpoint categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com