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 hosts a broad collection of endpoints spanning data analytics, AI/ML inference, finance/Web3 market data, and general-purpose utility services. Every endpoint is priced at $0.02 per request, settled in USDC on the Base network. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an x402 payment header to each request.
The specific endpoint `/api/v1/inbox/109` is listed as "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maximum cost of 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 platform also advertises sibling endpoints for metrics, reports, data export, insights, 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, no OpenAPI schema, request/response examples, or detailed documentation were found for any of these endpoints, so the exact input parameters and output formats remain unknown.
Capabilities
Use cases
- —Querying real-time financial data (prices, exchange rates, gas estimates) without managing API keys
- —Running AI inference tasks (sentiment analysis, summarization, classification, embeddings) on a per-call basis
- —Performing utility operations like geocoding, validation, and data conversion with instant pay-per-use access
- —Exporting data or generating analytics reports via micropayment-gated endpoints
Fit
Best for
- —Agents or bots that need keyless, pay-per-call access to diverse API services
- —Developers prototyping with low-cost, no-commitment API endpoints
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where $0.02/request adds up and bulk pricing is needed
- —Users who require detailed API documentation, SLAs, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/109 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no documentation beyond a landing page listing endpoint names. The specific purpose of /api/v1/inbox/109 is unclear — it is labeled generically as 'Premium API Access' with no further detail. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The specific function of /api/v1/inbox/109 is undocumented — 'Premium API Access' is a generic label
- —No request body format or response format is documented anywhere
- —The /api, /pricing, and /README pages all returned only a 'Connect wallet' prompt with no useful content
- —Cannot verify that the advertised AI, finance, and utility endpoints actually return meaningful data
Citations
- —The platform lists endpoints across data/analytics, AI/ML, finance/Web3, and infrastructure categories, all priced at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge for /api/v1/inbox/109 shows maxAmountRequired of 20000 base units of USDC on Base with 300s timeouthttps://lowpaymentfee.com/api/v1/inbox/109