x402-gated product inventory endpoint on Base, paid per-request in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a product inventory resource (product ID 30) behind an x402 paywall. It accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) via the x402 "exact" scheme.
The specific endpoint `/api/v1/products/30/inventory` is listed under the provider's umbrella as "Premium API Access." The broader lowpaymentfee.com platform advertises a suite of APIs spanning data & analytics, AI/ML inference, finance/Web3, and infrastructure utilities — all priced at $0.02 per request with no API keys, no rate limits, and instant access. However, this particular endpoint's x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (6 decimals), which equals $0.02 — consistent with the site-wide pricing.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no description of what the inventory payload actually contains. The endpoint is confirmed live (402 challenge captured), but without documentation or example responses, it is difficult to know exactly what data is returned.
Capabilities
Use cases
- —Querying real-time product inventory data for product ID 30
- —Integrating pay-per-request inventory checks into automated agent workflows
- —Demonstrating x402 protocol payment flows on Base
Fit
Best for
- —Agents or bots that need on-demand inventory lookups without subscription commitments
- —Developers experimenting with x402 micropayment-gated APIs
- —Workflows requiring keyless, permissionless API access on Base
Not for
- —Bulk inventory queries across many products (only product 30 is exposed at this path)
- —Users who need detailed API documentation or guaranteed SLAs
- —Applications requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/30/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The purpose of the 'product inventory' data is unexplained, making this effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request parameters or response format
- —The specific data returned by the inventory endpoint is unknown
- —Only product ID 30 is referenced; unclear if other product IDs are available
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/products/30/inventory
- —Site-wide pricing is $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/products/30/inventory