x402-gated product inventory endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a "Premium API Access" resource at the path `/api/v1/products/7/inventory`. It is part of a broader platform (lowpaymentfee.com) that offers a variety of x402-protocol pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services — all settled on the Base network using USDC.
The specific endpoint `/api/v1/products/7/inventory` accepts POST requests and returns JSON. Based on the x402 challenge, each call costs up to 20,000 base units of USDC (0.02 USD) on Base. The platform advertises a flat $0.02 per request across its API catalog, with no API keys, no rate limits, and no minimum commitments required. Payment is handled entirely via the x402 protocol's `X-PAYMENT` header.
Documentation beyond the landing page is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed description of what the inventory resource actually returns. The endpoint is confirmed live (returns a proper 402 challenge), but the lack of documentation makes it difficult to know what data to send or expect back.
Capabilities
Use cases
- —Querying product inventory data via a single paid API call
- —Integrating pay-per-request inventory checks into agent workflows
- —Accessing premium data without API key registration
Fit
Best for
- —Agents that can settle x402 payments in USDC on Base
- —Use cases requiring keyless, per-call API access
- —Developers exploring x402 protocol integrations
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume use cases where per-call pricing may add up without bulk discounts
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/7/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no documentation, no OpenAPI schema, no request/response examples, and the purpose of the 'products/7/inventory' resource is entirely opaque. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown.
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no content.
- —The specific purpose and data returned by /api/v1/products/7/inventory is not described anywhere.
- —The endpoint path suggests a specific product (ID 7) but no context is given about what products are offered.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base network.https://lowpaymentfee.com/api/v1/products/7/inventory
- —The platform advertises $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/products/7/inventory