Pay-per-call notification endpoint on Base via x402, settling in USDC at $0.02/request.
What it does
This endpoint at `/api/v1/notifications/23` is part of the lowpaymentfee.com platform, a collection of x402-enabled APIs spanning data analytics, AI/ML inference, finance, infrastructure utilities, and notifications. Each call is paid individually via the x402 protocol using USDC on the Base network, with no API keys, rate limits, or subscriptions required.
The specific endpoint probed (`/api/v1/notifications/23`) is labeled "Premium API Access" and costs up to $0.02 per request (maxAmountRequired of 20,000 base units of USDC, which has 6 decimals = $0.02). Payment is made via the x402 exact scheme to the specified payTo address. The endpoint accepts HTTP POST requests and returns `application/json` responses. The x402 challenge was successfully captured, confirming the endpoint is live.
Beyond this specific notifications endpoint, the platform advertises a broad catalog of similarly priced endpoints including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, and more — all at $0.02 per request. However, no OpenAPI schema, request/response examples, or detailed documentation were found for any of these endpoints, so the exact input parameters and response formats remain unknown.
Capabilities
Use cases
- —Sending or retrieving notifications via a pay-per-call model without API key management
- —Integrating notification functionality into agent workflows that settle payments on Base
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agent-based systems needing keyless, pay-per-use notification endpoints
- —Low-volume or sporadic notification needs where subscriptions are overkill
Not for
- —High-volume notification pipelines where per-request fees add up quickly
- —Users who need detailed API documentation or guaranteed SLAs
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/notifications/23 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is no OpenAPI schema, no request/response examples, and no documentation beyond a landing page listing endpoint names and prices. The purpose of '/api/v1/notifications/23' (what notification 23 refers to, what inputs it expects) is entirely unclear.
Warnings
- —No OpenAPI or schema documentation available for any endpoint on the platform
- —The specific function of /api/v1/notifications/23 is undocumented — it is unclear what 'notification 23' refers to or what request body is expected
- —No response examples or error handling documentation found
- —The /api, /pricing, and /README pages all returned only a 'Connect wallet' prompt with no useful content
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/notifications/23
- —All endpoints on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com