x402-gated premium API endpoint on Base, pay-per-request with USDC.
What it does
This endpoint at lowpaymentfee.com is one of many x402-protocol-gated API resources offered by the provider. The specific resource at `/api/v1/generate/resource/18` is labeled "Premium API Access" and accepts POST requests, returning JSON responses. Payment is settled on the Base network using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) with a maximum amount of 20,000 units (which, given USDC's 6 decimals, equates to $0.02 per request). The endpoint uses the x402 "exact" payment scheme, meaning each call requires a one-shot micropayment.
The provider's landing page advertises a broad catalog of APIs spanning data & analytics, AI & machine learning (sentiment analysis, 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 with no API keys, no rate limits, and no minimum commitments. However, the specific functionality behind `/api/v1/generate/resource/18` is not documented — the path suggests a generation or resource-creation endpoint, but no input/output schema, parameter documentation, or example responses are available.
The endpoint is confirmed live, returning a proper 402 challenge with x402 version 1 headers. Documentation pages (/docs, /pricing, /api, /README) all resolve but contain only a "Connect wallet" prompt with no substantive content. Without knowing what this endpoint actually generates or what POST body it expects, agents should treat this as an opaque paid resource until further documentation is published.
Capabilities
Use cases
- —Paying per-call for an undocumented generation/resource endpoint via x402
- —Integrating micropayment-gated API calls into agent workflows on Base
- —Testing x402 protocol payment flows against a live endpoint
Fit
Best for
- —Developers experimenting with x402 micropayment protocol
- —Agents that can handle x402 payment challenges on Base with USDC
- —Use cases where no API key management is desired
Not for
- —Production workloads requiring documented input/output schemas
- —Users who need free or authenticated-but-not-paid access
- —Anyone needing detailed documentation before integrating
Quick start
# The endpoint requires an x402 payment header (USDC on Base).
# 1. POST to the endpoint without payment to receive the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/generate/resource/18
# 2. Parse the 402 response, construct an X-PAYMENT header with a signed USDC transfer
# of 20000 units ($0.02) to 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
# 3. Retry the POST with the X-PAYMENT header attached.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/generate/resource/18",
"description": "Premium API Access",
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1
}Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, but there is zero documentation on what the endpoint actually does, what inputs it expects, or what a successful response looks like. All doc pages are empty stubs. The listing is essentially a stub with only payment metadata available.
Warnings
- —No documentation exists for this specific endpoint — all doc pages show only 'Connect wallet'
- —The purpose of /api/v1/generate/resource/18 is unknown; 'Premium API Access' is a generic label
- —No input schema or example request body is documented
- —No example of a successful (paid) response is available
- —The provider lists many endpoints but none appear to have public documentation
Citations
- —The endpoint returns a 402 challenge with x402 version 1, exact scheme, USDC on Base, maxAmountRequired 20000https://lowpaymentfee.com/api/v1/generate/resource/18
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and no minimumshttps://lowpaymentfee.com
- —The provider offers APIs across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) contain only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs