x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402 protocol API marketplace that gates access to a variety of endpoints behind per-request micropayments settled in USDC on the Base network. The specific endpoint at `/api/v1/backups/19` is listed as "Premium API Access" and accepts POST requests with an x402 payment challenge requiring up to 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals).
The broader platform advertises four categories of APIs: 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 priced at $0.02 per request with no API keys, no rate limits, and no minimum commitments required.
Documentation is extremely sparse — the docs, API, pricing, 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 detailed documentation available from the crawl. The endpoint is confirmed live via a valid 402 challenge, but the actual functionality behind `/api/v1/backups/19` specifically (as opposed to the other listed endpoints) is unclear from the available material.
Capabilities
Use cases
- —Paying per-request for data analytics, AI inference, or financial data without managing API keys or subscriptions
- —Integrating micropayment-gated API calls into autonomous agent workflows via x402
- —Accessing utility services like geocoding or data conversion with crypto-native billing
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —Agent-based systems that can handle x402 payment challenges natively
- —Users who prefer crypto-settled micropayments over traditional API billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integration
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/backups/19 \
-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/backups/19",
"description": "Premium API Access",
"maxAmountRequired": "20000",
"maxTimeoutSeconds": 300
}
],
"x402Version": 1
}Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation beyond a wallet-connect prompt, no request/response examples, and the specific purpose of the `/api/v1/backups/19` endpoint is unexplained. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —The specific endpoint /api/v1/backups/19 ('Premium API Access') does not match any of the publicly listed API categories; its actual functionality is unknown
- —No request body schema or response body examples available
Citations
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/backups/19