x402-gated premium API endpoint on Base network, paid per-request in USDC.
What it does
This endpoint at `/api/endpoint-9` is part of the lowpaymentfee.com platform, which offers a collection of x402 protocol-gated APIs spanning data & analytics, AI/ML inference, finance/Web3, and infrastructure utilities. The specific endpoint is labeled "Premium API Access" with no further description of its functionality beyond that generic title.
The endpoint is live and returns a valid x402 payment challenge. It accepts POST requests and requires payment via USDC (asset `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on the Base network. The maximum amount required per request is 20,000 units (in USDC's 6-decimal representation, this equates to $0.02). Payment is made via the `exact` scheme to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3`, with a timeout of 300 seconds.
Notably, this endpoint (`/api/endpoint-9`) does not appear in the site's publicly listed API catalog, which enumerates endpoints under `/api/v1/` and `/api/v2/` paths. The site's documentation, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no input/output documentation, and no examples available. Without knowing what this endpoint actually does, callers should treat it as an opaque premium service with unknown functionality.
Capabilities
Use cases
- —Programmatic access to an x402-gated premium service via USDC micropayments
- —Agent-driven API consumption without API keys or subscriptions
- —Testing x402 protocol payment flows on Base network
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can handle on-chain USDC payments on Base
- —Use cases where keyless, pay-per-request access is preferred
Not for
- —Users who need documented input/output schemas before integrating
- —Applications requiring guaranteed SLAs or support
- —Anyone needing to understand what the endpoint returns before paying
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-9
# Returns 402 with X-PAYMENT challenge; attach payment header to complete request.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/endpoint-9",
"description": "Premium API Access",
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1
}Endpoint
Quality
The endpoint is live and returns a valid 402 challenge, but there is zero documentation on what it actually does, no input/output schema, and the endpoint path doesn't appear in the site's own catalog. The docs/pricing/README pages are all empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —Endpoint /api/endpoint-9 is not listed in the site's public API catalog — its purpose is unknown
- —No input schema or output schema documented; callers cannot know what to send or what to expect
- —All documentation pages (docs, pricing, README) render only 'Connect wallet' with no content
- —Generic 'Premium API Access' label provides no indication of actual functionality
Citations
- —The endpoint returns a 402 challenge with USDC payment on Base network at $0.02 per requesthttps://lowpaymentfee.com/api/endpoint-9
- —The site lists APIs under /api/v1/ and /api/v2/ paths at $0.02/request with no API keys or rate limitshttps://lowpaymentfee.com
- —Documentation, pricing, and README pages show only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs