x402-gated premium API access endpoint on Base network, pay-per-request with USDC.
What it does
The `/api/v1/users` endpoint at lowpaymentfee.com is an x402-enabled API that requires per-request payment in USDC on the Base network. It is part of a broader platform offering multiple API categories including data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all gated behind x402 payment challenges.
This specific endpoint is labeled "Premium API Access" and accepts HTTP POST requests. The x402 challenge specifies a maximum payment of 20,000 units of USDC (token contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` on Base), with a timeout of 300 seconds. The platform advertises a flat rate of $0.02 per request across its endpoints, no API keys, no rate limits, and instant access.
Documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/users` endpoint actually returns or what input it expects. The endpoint is confirmed live (402 challenge captured), but the lack of documentation makes it difficult to determine the actual functionality beyond the generic "Premium API Access" label.
Capabilities
Use cases
- —Accessing a pay-per-request users API without traditional API key registration
- —Programmatic agent-driven API consumption via x402 micropayments
- —Integrating USDC-based payment flows into automated workflows
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can handle on-chain USDC payments on Base
- —Use cases requiring keyless, pay-as-you-go API access
Not for
- —Users who need detailed API documentation or schemas before integrating
- —Applications requiring free or subscription-based API access
- —Production systems that need guaranteed SLAs or documented error handling
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/users \
-H "Content-Type: application/json"
# Returns 402 with x402 payment challenge; include X-PAYMENT header after 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/users",
"description": "Premium API Access",
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1
}Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is essentially no documentation: no OpenAPI schema, no request/response examples, no description of what the /api/v1/users endpoint actually does. Docs pages are empty beyond a wallet connect prompt. The listing is effectively a stub.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or input/output schema provided; it is unknown what data /api/v1/users returns or what POST body it expects.
- —The endpoint name 'Premium API Access' is generic and does not describe actual functionality.
- —maxAmountRequired of 20000 USDC units — actual dollar cost is unclear without knowing token decimals context (likely $0.02 based on site pricing, but unconfirmed for this specific endpoint).
Citations
- —The endpoint returns a 402 x402 challenge with USDC on Base network, maxAmountRequired 20000, payTo 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/v1/users
- —Platform advertises $0.02 per request, no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —Multiple API categories offered: Data & Analytics, AI & ML, Finance & Web3, Infrastructurehttps://lowpaymentfee.com
- —Docs, pricing, API, and README pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs