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 75) via the x402 payment protocol. It is part of a broader platform that offers dozens of pay-per-call APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services — all gated behind x402 challenges on the Base network using USDC.
The specific endpoint `/api/v1/products/75/inventory` is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The platform's landing page confirms uniform $0.02/request pricing across all endpoints, with no API keys, no rate limits, and no minimum commitments required.
Documentation 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 spec, no request/response schema documentation, and no example payloads available. The endpoint name "Premium API Access" and path segment "products/75/inventory" suggest it returns inventory data for a specific product, but the exact request body format and response structure are unknown. The endpoint is confirmed live (returns a valid 402 challenge).
Capabilities
Use cases
- —Querying inventory levels for a specific product via a micropayment-gated API
- —Integrating pay-per-request product data into an agent workflow without API key management
- —Accessing product inventory data settled on Base L2 with USDC
Fit
Best for
- —Agents that need on-demand product inventory data without subscription overhead
- —Developers exploring x402 payment protocol integrations
- —Workflows requiring keyless, pay-as-you-go API access on Base
Not for
- —High-volume inventory polling where per-request fees would accumulate significantly
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Non-crypto workflows that cannot settle payments in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/75/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is zero documentation on request/response schemas, no OpenAPI spec, and the docs pages are empty. The purpose of this specific endpoint ('products/75/inventory') is vague — 'Premium API Access' is a generic label. Effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No request body schema or response schema documented; callers must guess the payload format
- —The endpoint path suggests a specific product (ID 75) but no context is given about what products are available or what 'inventory' returns
- —The generic title 'Premium API Access' does not describe the actual functionality
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/products/75/inventory
- —Platform pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/products/75/inventory