x402-gated product inventory endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a product inventory resource (product ID 81) via the x402 payment protocol. It accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) with a maximum cost of 0.02 USDC per request (20,000 base units at 6 decimals).
The endpoint is part of a broader platform (lowpaymentfee.com) that offers a variety of x402-gated APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request. The platform advertises no API keys, no rate limits, and instant access; callers simply attach an x402 payment header to each request.
The specific functionality of this particular endpoint — product inventory lookup — is not well-documented. The landing page lists many other endpoints but does not explicitly list this /products/81/inventory route, so its request schema, expected input fields, and response format are unknown. The x402 challenge confirms the endpoint is live and accepting payment-gated POST requests, but without further documentation or example responses, the exact data returned remains unclear.
Capabilities
Use cases
- —Querying inventory status for a specific product via a micropayment-gated API call
- —Integrating pay-per-use product data into an agent workflow without API key management
- —Programmatic inventory checks settled in USDC on Base L2
Fit
Best for
- —Agents or bots that need on-demand inventory data without subscription commitments
- —Developers experimenting with x402 payment-gated API patterns
- —Use cases requiring crypto-native per-call billing on Base
Not for
- —High-volume inventory polling where per-call costs would accumulate quickly
- —Users who need detailed API documentation and guaranteed SLAs before integrating
- —Non-crypto workflows that cannot produce x402 payment headers
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/81/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge confirms the endpoint is live and pricing is clear ($0.02 USDC on Base). However, there is no documentation for this specific endpoint's request/response schema, no OpenAPI spec, and the crawled docs/pricing/API pages returned only 'Connect wallet' with no useful content. The endpoint path (/products/81/inventory) is not listed on the landing page, making its purpose largely opaque.
Warnings
- —No documentation found for this specific endpoint (/api/v1/products/81/inventory); it is not listed among the advertised APIs on the landing page.
- —No request or response schema available — input fields and output format are unknown.
- —Docs, pricing, API, and README pages all returned only 'Connect wallet' with no substantive content.
- —The endpoint's actual functionality (what 'product 81 inventory' represents) is unclear.
Citations
- —The endpoint returns a 402 challenge requesting USDC payment on Base network with maxAmountRequired of 20000 base units.https://lowpaymentfee.com/api/v1/products/81/inventory
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base.https://lowpaymentfee.com/api/v1/products/81/inventory
- —The platform advertises $0.02 per request, no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The landing page lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories but does not list this specific /products/81/inventory endpoint.https://lowpaymentfee.com