Pay-per-call notification endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This endpoint at lowpaymentfee.com provides a "Premium API Access" notification service accessible via the x402 payment protocol. It is one of many endpoints offered by the lowpaymentfee.com platform, which hosts a broad catalog of pay-per-call APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request with no API keys, no rate limits, and no commitments.
The specific endpoint `/api/v1/notifications/20` accepts POST requests and is gated by an x402 challenge requiring payment of up to 20,000 base units of USDC (0x8335…2913) on the Base network, which equals $0.02 USD (USDC uses 6 decimals). Payment is made via the `exact` scheme to the address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3`, with a maximum timeout of 300 seconds. The response MIME type is `application/json`.
Documentation beyond the landing page is sparse — the /api, /pricing, and /README pages all resolve to a "Connect wallet" prompt with no further detail. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the notification endpoint actually returns or what parameters it accepts. The endpoint is confirmed live (returns a proper 402 challenge), but the exact functionality behind "notifications/20" is unclear from available materials.
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 settled on-chain
- —Testing x402 payment protocol integrations with a live, inexpensive endpoint
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —Agents needing simple pay-per-call notification endpoints on Base
- —Projects that want keyless API access with crypto micropayments
Not for
- —Production notification systems requiring documented SLAs and detailed schemas
- —Users who need fiat-only payment options (this requires USDC on Base)
- —Applications needing high-throughput bulk notification delivery with guaranteed delivery semantics
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/notifications/20 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation of what the notifications endpoint does or what parameters it accepts, and the /api, /pricing, and /README pages are all empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No documentation available for the /api/v1/notifications/20 endpoint — purpose and parameters are unknown
- —No OpenAPI or schema definition found
- —The /api, /pricing, and /README pages return only a 'Connect wallet' prompt with no useful content
- —The meaning of '20' in the endpoint path is unclear (could be an ID, a parameter, etc.)
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/notifications/20
- —All APIs 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 APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/notifications/20