x402-gated product inventory endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a product inventory resource (product ID 15) via the x402 payment protocol. It is part of a broader platform that offers dozens of pay-per-request API endpoints spanning data analytics, AI/ML inference, finance, crypto, and utility services — all gated behind x402 micropayments on the Base network.
The specific endpoint `/api/v1/products/15/inventory` is listed as "Premium API Access" and accepts POST requests. Payment is settled in USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base. The x402 challenge advertises a maxAmountRequired of 20,000 base units, which at 6 decimals for USDC equals $0.02 per request — consistent with the platform's uniform $0.02/request pricing. No API keys or rate limits are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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 schema, no request/response examples, and no description of what the inventory data actually contains. The endpoint is confirmed live (402 challenge captured), but the lack of documentation makes it difficult to know what fields to send or what shape the response takes.
Capabilities
Use cases
- —Querying product inventory data with per-request USDC micropayments
- —Integrating inventory checks into automated agent workflows without API key management
- —Accessing product availability information via crypto-native payment rails
Fit
Best for
- —Agents or services that need on-demand inventory lookups without subscription commitments
- —Developers building on Base who want USDC-settled API access
- —Automated workflows requiring keyless, pay-as-you-go API consumption
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume use cases where $0.02/request adds up significantly
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/15/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages return only a wallet-connect prompt. The purpose of this specific endpoint ('products/15/inventory') is not explained beyond the generic label 'Premium API Access'.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all return only 'Connect wallet' with no content
- —No OpenAPI or request/response schema provided; request body format and response shape are unknown
- —The endpoint name 'Premium API Access' is generic and does not describe what inventory data is returned
- —Product ID 15 is hardcoded in the URL; unclear if other product IDs are available or what they represent
Citations
- —The platform charges $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The x402 challenge shows maxAmountRequired of 20000 base units in USDC (6 decimals) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/products/15/inventory
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/products/15/inventory
- —Documentation pages (/docs, /api, /pricing, /README) contain no substantive contenthttps://lowpaymentfee.com/docs