Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. It is one of many endpoints offered by the lowpaymentfee.com platform, which hosts a variety of API categories including Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure utilities. All endpoints on the platform 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 `/api/v1/payments/368` is listed as "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting a maximum of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base (asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
However, the exact functionality behind this particular endpoint path (`/payments/368`) is not documented beyond the generic label "Premium API Access." The platform's landing page lists many other endpoints with clearer descriptions (sentiment analysis, summarization, geocoding, etc.), but this specific path does not appear among them. There is no OpenAPI schema, no request/response examples, and the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further documentation. Prospective users should be aware that the actual behavior of this endpoint is unclear from available materials.
Capabilities
Use cases
- —Accessing a premium API resource with per-call USDC micropayments on Base
- —Integrating x402-compatible payment flows into agent workflows
- —Testing x402 protocol payment challenges against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC payments on Base L2
- —Use cases requiring keyless, pay-per-request API access
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Applications requiring free or fiat-settled API access
- —Production workloads that depend on well-documented request/response contracts
Quick start
# The endpoint returns 402 until a valid X-PAYMENT header is provided.
curl -X POST https://lowpaymentfee.com/api/v1/payments/368 \
-H "Content-Type: application/json"
# Response: 402 with x402 challenge. Use an x402 client to attach payment.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/368",
"description": "Premium API Access",
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1
}Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and the specific functionality of /api/v1/payments/368 is entirely undocumented. The docs pages render only a wallet-connect prompt.
Warnings
- —The exact functionality of /api/v1/payments/368 is undocumented — 'Premium API Access' is a generic label with no specification of what data or service is returned after payment.
- —No OpenAPI schema, request body format, or response schema is available.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no usable content.
- —This endpoint path does not appear in the platform's listed API catalog on the landing page.
Citations
- —The platform lists endpoints at $0.02/request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge confirms the endpoint is live, requesting 20000 base units of USDC (0.02 USD) on Base with a 300-second timeout.https://lowpaymentfee.com/api/v1/payments/368
- —The platform offers categories including Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com