Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad set of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. Every endpoint costs $0.02 per request, paid in USDC on the Base network via the x402 protocol. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/payments/24` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The 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 (geocoding, validation, conversion, generation). However, the crawled documentation pages (docs, pricing, README) all returned only a "Connect wallet" prompt with no substantive content, so the actual capabilities and response formats of individual endpoints remain undocumented.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification, embeddings) without managing API keys
- —Fetching real-time financial data like token quotes, gas estimates, and exchange rates via micropayments
- —Running geocoding or data validation calls with per-request billing and no subscription overhead
- —Exporting analytics data or generating insights on a pay-as-you-go basis
Fit
Best for
- —AI agents and bots that can settle x402 payments autonomously on Base
- —Developers who want zero-friction API access without signup or key management
- —Low-volume or bursty workloads where per-request pricing beats subscriptions
Not for
- —High-volume production workloads where $0.02/request adds up significantly
- —Users without a Base-compatible wallet or USDC holdings
- —Applications requiring detailed API documentation, SLAs, or guaranteed uptime
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/24 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Example
Request
{
"url": "https://lowpaymentfee.com/api/v1/payments/24",
"body": {},
"method": "POST",
"headers": {
"X-PAYMENT": "<x402-payment-token>",
"Content-Type": "application/json"
}
}Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation pages are effectively empty (all show only 'Connect wallet'), there is no OpenAPI spec, no response schema, no example responses, and the actual functionality behind '/api/v1/payments/24' ('Premium API Access') is vague. The platform lists many endpoints on its landing page but provides no detail on request/response formats.
Warnings
- —Documentation pages (/docs, /pricing, /README, /api) all returned only 'Connect wallet' with no usable content
- —No OpenAPI or schema documentation available for any endpoint
- —The specific endpoint '/api/v1/payments/24' is labeled 'Premium API Access' but its actual functionality is unclear — it does not appear in the landing page's listed APIs
- —Response format and fields are completely undocumented
- —No information on uptime, SLAs, or error handling
Citations
- —All listed endpoints cost $0.02 per request with no minimums or API keyshttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/payments/24 requests maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/24
- —Payment is in USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/payments/24