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 65) via the x402 payment protocol. The endpoint is live and returns a 402 challenge requiring payment in USDC on the Base network. The specific path `/api/v1/products/65/inventory` suggests it returns inventory data for a particular product, though no response schema or documentation beyond the challenge itself is available.
The provider, lowpaymentfee.com, operates a broader platform offering multiple x402-gated API categories including data & analytics, AI/ML inference, finance & Web3 data, and infrastructure utilities — all priced at $0.02 per request. This particular endpoint's x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (which uses 6 decimals), equating to $0.02 per call. Payment is settled on the Base L2 network to the specified wallet address, with no API keys or rate limits required.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema beyond the x402 outputSchema stub, and no examples of what the inventory response actually contains. The endpoint accepts POST requests as indicated by the challenge's outputSchema.
Capabilities
Use cases
- —Querying real-time inventory levels for a specific product
- —Integrating inventory checks into automated purchasing workflows
- —Agent-driven stock monitoring with per-call USDC micropayments
Fit
Best for
- —Agents needing on-demand inventory data without API key management
- —Micropayment-based access to product stock information
- —Crypto-native applications on Base network
Not for
- —Bulk inventory queries across many products (only product 65 is exposed at this path)
- —Users who need detailed documentation or response schema guarantees before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/65/inventory \
-H "X-PAYMENT: <x402-payment-header>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI spec, no request/response examples, and the crawled pages are essentially empty beyond the homepage listing. The specific function of this inventory endpoint is only inferable from the URL path. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all return only a wallet-connect prompt with no content.
- —No request body schema or response schema documented; unclear what data the inventory endpoint actually returns.
- —Only a single product ID (65) is exposed at this path; unclear if other product IDs are available.
- —The provider lists many API categories on the homepage but this specific endpoint (/products/65/inventory) is not among them, raising questions about its intended use.
Citations
- —The endpoint returns a 402 challenge with x402Version 1, requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/products/65/inventory
- —maxAmountRequired is 20000 base units of USDC (USD Coin, 6 decimals) = $0.02https://lowpaymentfee.com/api/v1/products/65/inventory
- —The provider advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/products/65/inventory