x402-gated product inventory endpoint on Base, paid per-request in USDC.
What it does
This endpoint at lowpaymentfee.com exposes a product inventory resource at `/api/v1/products/67/inventory` behind an x402 paywall. It accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) via the x402 "exact" scheme. The maximum amount required per call is 20,000 base units of USDC, which equals $0.02 (USDC uses 6 decimals).
The broader lowpaymentfee.com platform advertises a suite of x402-gated APIs spanning data analytics, AI/ML inference (sentiment, summarization, classification, embeddings), finance/Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation) — all priced at $0.02 per request with no API keys, no rate limits, and no commitments. However, this specific listing is for the product inventory endpoint (`/api/v1/products/67/inventory`), which is not listed on the site's main catalog. Its exact response payload and purpose are unclear from available documentation.
The endpoint is confirmed live: it returns a well-formed x402 version 1 challenge with a 402 status code. Documentation on the site is extremely thin — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples available for this specific endpoint.
Capabilities
Use cases
- —Querying product inventory data for product ID 67 via a pay-per-request model
- —Integrating inventory checks into agent workflows that settle payments on Base in USDC
- —Accessing a keyless API endpoint without subscription or rate-limit constraints
Fit
Best for
- —Agents or services that need on-demand inventory data without managing API keys
- —Crypto-native workflows settling microtransactions on Base L2
- —Developers exploring x402 protocol integrations
Not for
- —Users who need detailed API documentation or response schema guarantees before integrating
- —High-volume inventory polling where $0.02 per request adds up significantly
- —Non-crypto workflows that cannot handle x402 payment challenges
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/67/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, but there is no documentation, no OpenAPI spec, no request/response examples, and the specific endpoint (/api/v1/products/67/inventory) is not listed on the provider's own catalog page. The purpose and response format are entirely unknown.
Warnings
- —No OpenAPI spec or schema documentation available for this endpoint
- —This specific endpoint (/api/v1/products/67/inventory) is not listed on the provider's main API catalog — its purpose is unclear
- —All documentation pages (docs, API, pricing, README) render only a 'Connect wallet' prompt with no useful content
- —Request body schema and response schema are completely unknown
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/products/67/inventory
- —The platform advertises $0.02 per request pricing 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/67/inventory