Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint at `/api/v1/payments/142` is labeled "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per call (USDC uses 6 decimals). Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises multiple API categories including 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 listed at $0.02 per request. The platform emphasizes no API keys, no rate limits, and instant access.
However, the specific endpoint `/api/v1/payments/142` does not clearly map to any of the advertised API categories — it sits under a `/payments/` path with a numeric ID, and its description is simply "Premium API Access" with no further documentation on what data or functionality it returns. The docs, pricing, and README pages all rendered as just "Connect wallet" with no substantive content. Without an OpenAPI schema, request/response examples, or detailed documentation, the actual behavior of this endpoint remains unclear.
Capabilities
Use cases
- —Programmatic access to a premium API endpoint paid per-call with USDC on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC payments on Base L2
- —Use cases requiring no-signup, no-API-key access
Not for
- —Users who need detailed documentation or OpenAPI specs before integrating
- —Anyone without a Base-network USDC wallet
- —Production workloads requiring guaranteed SLAs or support
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/142 \
-H "Content-Type: application/json"
# Returns 402 with x402 payment challenge; attach X-PAYMENT header with signed USDC payment to access.Example
Response
{
"error": "X-PAYMENT header is required",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3",
"scheme": "exact",
"network": "base",
"mimeType": "application/json",
"resource": "https://lowpaymentfee.com/api/v1/payments/142",
"description": "Premium API Access",
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1
}Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the endpoint path '/api/v1/payments/142' does not clearly correspond to any advertised service. All doc pages returned only 'Connect wallet' with no content.
Warnings
- —No OpenAPI or schema available — actual request format and response payload are unknown
- —The endpoint path /api/v1/payments/142 does not match any of the advertised API categories on the homepage
- —All documentation pages (docs, pricing, README, api) returned only 'Connect wallet' with no substantive content
- —No information on what 'Premium API Access' actually provides or returns after payment
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/payments/142
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform advertises categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com