Pay-per-call notification endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This endpoint at `/api/v1/notifications/55` is part of the lowpaymentfee.com platform, which offers a collection of pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services. All endpoints use the x402 protocol on the Base network, accepting USDC payments with no API keys, no rate limits, and no subscriptions required.
The specific endpoint probed (`/api/v1/notifications/55`) is labeled "Premium API Access" and costs $0.02 per request (20,000 base units of USDC with 6 decimals). It accepts POST requests and returns `application/json`. Payment is made via the x402 exact scheme to the specified wallet address on Base. The x402 challenge was successfully captured, confirming the endpoint is live.
The broader platform advertises 16+ endpoints across categories including metrics, reports, data export, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 per request price point. However, no OpenAPI schema, detailed documentation, or example request/response payloads are available for any of these endpoints, making it difficult to know exactly what parameters to send or what data structures to expect back.
Capabilities
Use cases
- —Sending or retrieving notifications via a pay-per-call model without needing API keys
- —Integrating low-cost notification functionality into agent workflows on Base
- —Testing x402 protocol integrations with a cheap, live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-per-use API access on Base
- —Low-volume notification use cases where $0.02/call is acceptable
Not for
- —High-volume notification needs where per-call costs would accumulate quickly
- —Users who need detailed API documentation or guaranteed SLAs
- —Anyone requiring non-USDC or non-Base payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/notifications/55 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI schema, no documentation beyond a landing page listing, no example requests or responses, and the purpose of the 'notifications/55' endpoint is entirely unclear. The listing is effectively a stub.
Warnings
- —No OpenAPI or schema documentation available for any endpoint on this platform
- —The specific function of /api/v1/notifications/55 is undocumented — 'Premium API Access' is a generic label
- —No example request or response payloads are available; input parameters are unknown
- —The /api, /pricing, and /README pages all returned only a 'Connect wallet' prompt with no useful content
- —The endpoint path includes a numeric ID (55) with no explanation of what it references
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/notifications/55
- —All endpoints on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers 16+ endpoints across data/analytics, AI/ML, finance/web3, and infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/notifications/55