Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints across four categories: 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 priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol.
The specific endpoint `/api/v1/keys/72` is listed as "Premium API Access" and carries a maximum charge of 20,000 base units of USDC (0.02 USDC, i.e., $0.02) per call. Payment is settled on-chain to a Base address, with a 300-second timeout window. No API keys or rate limits are advertised — access is gated entirely by the x402 payment header. The platform emphasizes simplicity: no subscriptions, no minimums, and no commitments.
Documentation is minimal. The crawled /api, /pricing, and /README pages all resolve to a "Connect wallet" prompt with no additional content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the site. The exact functionality behind the "Premium API Access" label at `/api/v1/keys/72` is unclear — it may be a meta-endpoint for generating or managing access keys, but this is speculative. Agents should probe the endpoint with a valid x402 payment to discover the actual response format.
Capabilities
Use cases
- —Agents paying per-call for AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes and gas estimates via micropayment
- —On-demand geocoding, data validation, or unit conversion with no subscription
Fit
Best for
- —AI agents that need stateless, key-free API access via on-chain micropayments
- —Developers prototyping with low-cost, no-commitment API calls
- —Web3-native applications that prefer USDC-on-Base settlement
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users who need detailed API documentation or SLAs before integrating
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/72 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and the specific purpose of /api/v1/keys/72 ('Premium API Access') is ambiguous. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The exact functionality of /api/v1/keys/72 ('Premium API Access') is unclear — it may be a key management endpoint rather than a data endpoint
- —All documentation pages (/api, /pricing, /README) returned only a 'Connect wallet' prompt with no useful content
- —No request or response examples are available
Citations
- —All endpoints priced at $0.02 per request with no minimums or commitmentshttps://lowpaymentfee.com
- —Endpoint categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0.02 USD) on Base networkhttps://lowpaymentfee.com/api/v1/keys/72
- —Payment settled to 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with 300-second timeouthttps://lowpaymentfee.com/api/v1/keys/72
- —No API keys, no rate limits, instant access advertisedhttps://lowpaymentfee.com