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 variety of endpoints across data & analytics, AI & machine learning, finance & Web3, and infrastructure/utility categories. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, rate limits, or commitments required.
The specific endpoint at `/api/v1/payments/388` is labeled "Premium API Access" and accepts POST requests. The x402 challenge advertises a max amount of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is settled on-chain to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The platform lists 16 endpoints spanning metrics, reports, data export, insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation. However, documentation pages (/docs, /api, /pricing, /README) all returned only a "Connect wallet" prompt with no substantive content, so the actual behavior, input schemas, and response formats for these endpoints remain undocumented. The "Premium API Access" label on this particular endpoint does not clarify which specific service it provides.
Capabilities
Use cases
- —Programmatic access to utility and data APIs without traditional API key registration
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Accessing AI inference, financial data, or geocoding endpoints with per-request crypto payments
Fit
Best for
- —Developers or agents who want keyless, pay-per-use API access
- —Users already holding USDC on Base who want frictionless micropayments
- —Prototyping and low-volume usage where $0.02/call is cost-effective
Not for
- —High-volume production workloads where per-call crypto settlement adds overhead
- —Users who need detailed API documentation, SDKs, or guaranteed SLAs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/388 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no input/output schema, and the 'Premium API Access' label is generic. All doc pages returned only 'Connect wallet' with no useful content, making it impossible to determine what this endpoint actually does.
Warnings
- —No documentation available — all doc pages (/docs, /api, /pricing, /README) return only 'Connect wallet' with no content
- —The endpoint label 'Premium API Access' is vague and does not describe what the endpoint does or returns
- —No input schema or output schema beyond basic HTTP POST method is provided
- —No OpenAPI spec, ai-plugin manifest, or agents.txt found
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/payments/388
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/388
- —Platform lists 16 endpoints across data, AI, finance, and infrastructure categorieshttps://lowpaymentfee.com