x402-gated product inventory endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a product inventory resource (product ID 54) via the x402 payment protocol. It is part of a broader platform that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance, crypto, and utility services — all priced at $0.02 per request and settled in USDC on the Base network.
The specific endpoint `/api/v1/products/54/inventory` is listed as "Premium API Access" and accepts HTTP POST requests. Payment is handled inline via the x402 protocol: callers attach an `X-PAYMENT` header containing a signed USDC payment of up to 20,000 base units (i.e., $0.02, since USDC uses 6 decimals). The payment is sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base mainnet, using the USDC contract at `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`. No API keys or accounts are required; access is granted purely through payment.
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 description of what the inventory data actually contains. The endpoint is confirmed live (returns a proper 402 challenge), but the lack of documentation makes it difficult to know what payload to send or what response to expect.
Capabilities
Use cases
- —Querying product inventory data for product ID 54 via a single paid API call
- —Integrating pay-per-request inventory checks into automated agent workflows
- —Demonstrating x402 protocol payment flows on Base mainnet
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —Agents that need on-demand inventory data without managing API keys
- —Use cases requiring micro-payment-gated data access on Base
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —High-volume inventory queries where per-request pricing may not be cost-effective
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/54/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"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 schema, no request/response examples, and all documentation pages return only a wallet-connect prompt. The purpose of this specific endpoint ('Premium API Access' for product 54 inventory) is vague and undocumented.
Warnings
- —No API documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request body or response format
- —The endpoint name 'Premium API Access' is generic and does not describe what inventory data is returned
- —No request or response examples available anywhere in crawled content
- —Cannot verify what data the endpoint actually returns without making a paid request
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/products/54/inventory
- —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
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/products/54/inventory