x402-gated product inventory endpoint on Base, pay-per-request with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a product inventory resource (product ID 83) 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 per request (20,000 base units at 6 decimals). No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The hosting provider, lowpaymentfee.com, offers a broader catalog of x402-gated APIs spanning data/analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities, all priced at $0.02 per call. However, this specific endpoint is listed under "Premium API Access" and targets product inventory data. The exact schema of the inventory response is not documented in the crawled material, so the structure of the returned JSON is unknown.
The endpoint is live and returns a well-formed x402 version 1 challenge with a 300-second payment timeout. Documentation pages on the site (docs, pricing, README) appear to require wallet connection and did not yield substantive content during the crawl, so details about request body format, response fields, and error handling are unavailable.
Capabilities
Use cases
- —Querying real-time inventory levels for a specific product
- —Integrating pay-per-call inventory checks into an agent workflow
- —Accessing product stock data without managing API keys or subscriptions
Fit
Best for
- —AI agents that need on-demand inventory data with crypto micropayments
- —Developers experimenting with x402 payment-gated APIs
- —Applications on Base network that want frictionless USDC-settled API access
Not for
- —Bulk inventory queries requiring thousands of calls per second (no documented rate limits but cost adds up)
- —Users who need detailed API documentation or response schema guarantees before integrating
- —Non-crypto workflows that cannot produce x402 payment headers
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/83/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation on request body format, response schema, or what 'product inventory' actually contains. The docs/pricing/README pages all gate behind wallet connection and yielded no content. This is effectively a stub listing with confirmed liveness.
Warnings
- —No documentation available — docs, pricing, and README pages require wallet connection and returned no content
- —Request body schema is unknown; no OpenAPI spec or examples provided
- —Response schema is unknown; the actual inventory data structure is undocumented
- —The endpoint name 'Premium API Access' is generic and does not describe the actual functionality
- —Cannot verify what data is actually returned without making a paid request
Citations
- —Endpoint returns x402 version 1 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/products/83/inventory
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/products/83/inventory
- —Site advertises $0.02 per request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Payment timeout is 300 secondshttps://lowpaymentfee.com/api/v1/products/83/inventory