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 broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no subscriptions required. The x402 protocol handles payment inline: callers attach a signed USDC payment in the X-PAYMENT header and receive the response immediately.
The specific endpoint at `/api/v1/payments/369` 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 endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, documentation beyond the landing page is essentially empty (docs, pricing, and README pages only show a "Connect wallet" prompt), so the actual request/response schemas for individual endpoints are unknown.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification) without API key management
- —Fetching real-time crypto token quotes and gas estimates via micropayment
- —Geocoding or data validation as a utility service with no subscription commitment
- —Exporting analytics data or generating insights on a per-request billing model
Fit
Best for
- —AI agents that need keyless, pay-per-call access to diverse utility endpoints
- —Developers prototyping with low-cost API calls and no signup friction
- —Web3-native applications already holding USDC on Base
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Applications requiring non-USDC or non-Base-network payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/369 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what this specific 'Premium API Access' endpoint actually does. The docs, pricing, and README pages are all blank beyond a wallet-connect prompt. The listing is effectively a stub.
Warnings
- —No documentation available — docs, pricing, and README pages only show 'Connect wallet'
- —No OpenAPI or request/response schema for any endpoint
- —The purpose of '/api/v1/payments/369' specifically (vs. the other listed endpoints) is unclear
- —Cannot verify that the advertised AI, finance, or utility endpoints actually function as described
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 (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/payments/369
- —Platform lists endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com
- —Documentation pages (docs, pricing, README) contain only a 'Connect wallet' prompt with no substantive contenthttps://lowpaymentfee.com/docs