Pay-per-call notification endpoint on Base via x402 — $0.02 per request in USDC.
What it does
This endpoint at `/api/v1/notifications/18` is part of the lowpaymentfee.com platform, which offers a suite of pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services. All endpoints use the x402 payment protocol, settling in USDC on the Base network. The specific endpoint probed here is described as "Premium API Access" and accepts POST requests.
The x402 challenge confirms the endpoint is live and requires a maximum payment of 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this translates to $0.02 per request — consistent with the site's advertised flat pricing of $0.02/request across all endpoints. Payment is made to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The platform advertises no API keys, no rate limits, and instant access. However, there is no OpenAPI schema, no documentation beyond the landing page, and no example request/response payloads available. The exact functionality of the `/notifications/18` endpoint is unclear — the name suggests a notification-related service but no further details are provided. The broader platform lists 16+ endpoints across categories like sentiment analysis, text summarization, geocoding, price feeds, and more, all at the same $0.02 price point.
Capabilities
Use cases
- —Triggering or retrieving notifications via a pay-per-call model
- —Agent-driven workflows that need low-friction API access without API keys
- —Programmatic notification delivery settled in USDC on Base
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —High-volume use cases where $0.02/request adds up significantly
- —Anyone requiring fiat-only payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/notifications/18 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing. However, there is no OpenAPI schema, no documentation for this specific endpoint, no example request/response payloads, and the actual functionality of /notifications/18 is undefined. The listing is essentially a stub with confirmed liveness and pricing.
Warnings
- —No documentation exists for the /api/v1/notifications/18 endpoint — its exact functionality is unknown
- —No OpenAPI spec or request/response schema available
- —The /api, /pricing, and /README pages all returned only a 'Connect wallet' prompt with no useful content
- —The broader platform lists many endpoints but none have documented input/output schemas
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/notifications/18
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/notifications/18