Pay-per-call product inventory endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This x402-enabled endpoint at lowpaymentfee.com provides access to product inventory data for product ID 20. It is part of a broader suite of pay-per-request APIs offered by the same provider, spanning data analytics, AI/ML inference, finance, and utility categories. All endpoints on the platform share a uniform pricing model of $0.02 per request, paid in USDC on the Base network with no API keys, rate limits, or upfront commitments required.
The specific endpoint `/api/v1/products/20/inventory` accepts POST requests and returns JSON. Payment is handled via the x402 protocol: callers receive a 402 challenge containing the payment parameters (asset, amount, payTo address), construct an on-chain USDC payment on Base, and include the payment proof in the `X-PAYMENT` header. The max amount required is 20,000 base units of USDC (6 decimals), which equals $0.02. The payment timeout is 300 seconds.
Documentation beyond the landing page is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema, and no example payloads available. The endpoint is confirmed live (returns a valid 402 challenge), but the actual data returned after successful payment is unknown. The listing title "Premium API Access" is the provider's generic label and does not clarify what inventory data is served.
Capabilities
Use cases
- —Querying real-time inventory levels for a specific product via a single paid API call
- —Integrating inventory checks into an autonomous agent workflow that can settle payments on Base
- —Demonstrating x402 protocol payment flows in a development or testing environment
Fit
Best for
- —Agents or services that need on-demand inventory data without subscription commitments
- —Developers experimenting with x402 pay-per-call payment flows on Base
- —Low-volume consumers who prefer per-request pricing over monthly plans
Not for
- —High-volume inventory monitoring where per-request fees would accumulate significantly
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Anyone without a Base-compatible wallet or USDC holdings
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/20/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge and 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 inventory data is unclear. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request body and response format are completely unknown
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no content
- —The specific data returned by the /products/20/inventory endpoint is undocumented
- —Provider appears to be a demo or early-stage platform; reliability and data quality are unverified
Citations
- —Endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units USDC on Basehttps://lowpaymentfee.com/api/v1/products/20/inventory
- —Platform pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/products/20/inventory
- —Documentation, API, pricing, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs