Pay-per-call notification endpoint on Base via x402 — $0.02 per request in USDC.
What it does
This endpoint at `/api/v1/notifications/29` is part of the lowpaymentfee.com platform, which offers a collection of pay-per-request APIs settled via the x402 protocol on the Base network using USDC. The specific endpoint is labeled "Premium API Access" and accepts POST requests. Payment is 20,000 base units of USDC (6 decimals), which equals $0.02 per call. No API keys or rate limits are advertised; callers pay per request with an x402 payment header.
The broader lowpaymentfee.com platform lists endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure (geocoding, validation, conversion, generation). All are priced at $0.02 per request. However, this specific listing covers only the `/api/v1/notifications/29` endpoint, whose exact functionality is not documented beyond the generic "Premium API Access" label. There is no OpenAPI schema, no request/response examples, and no detailed documentation available from the crawled pages. The endpoint is live and returns a valid x402 challenge, but what data or action it provides upon successful payment is unclear.
Capabilities
Use cases
- —Sending or retrieving notifications via a pay-per-call model without API key management
- —Integrating low-cost notification triggers into agent workflows
- —Testing x402 payment flows against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —Agents needing simple pay-per-request notification access
- —Projects that want to avoid API key provisioning and subscriptions
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —High-volume notification use cases where per-call pricing adds up quickly
- —Anyone needing clarity on exactly what data the endpoint returns before paying
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/notifications/29 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the purpose of this specific notifications/29 endpoint is entirely unclear beyond the generic label 'Premium API Access'. Pricing is clear ($0.02 USDC on Base), but functional details are absent.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The exact functionality of /api/v1/notifications/29 is undocumented — 'Premium API Access' is a generic label
- —No request body schema or response examples are available
- —The /api, /pricing, and /README pages returned only a 'Connect wallet' prompt with no useful content
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/notifications/29
- —All endpoints on lowpaymentfee.com are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/notifications/29