x402-gated product inventory endpoint on Base, paid per-request in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a product inventory resource (product ID 99) via the x402 payment protocol. It is part of a broader platform that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance, crypto, and utility services — all gated behind x402 micropayments on the Base network using USDC.
The specific endpoint `/api/v1/products/99/inventory` accepts POST requests and returns JSON. 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 a flat $0.02/request pricing model across all endpoints, with no API keys, no rate limits, and no minimum commitments required.
Documentation is extremely sparse — the /docs, /pricing, /api, 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 usage examples available. The endpoint itself is live (returns a proper 402 challenge), but without documentation it is unclear what request body the inventory endpoint expects or what shape the response takes. The listing title "Premium API Access" is generic and does not describe the actual functionality.
Capabilities
Use cases
- —Querying inventory status for a specific product via micropayment
- —Integrating pay-per-call product data into an agent workflow
- —Accessing product inventory without API key registration
Fit
Best for
- —Agents that need on-demand product inventory checks without subscription commitments
- —Developers exploring x402 micropayment-gated APIs on Base
- —Automated systems that can pay per-request in USDC
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume inventory polling where per-request fees would accumulate significantly
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/99/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 no documentation, no OpenAPI spec, no request/response schema, and no examples. The endpoint's actual functionality (what 'product 99 inventory' means) is entirely opaque. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition found; request body format and response shape are unknown
- —The endpoint path references a specific product ID (99) with no explanation of what product this represents or whether other IDs are valid
- —Listing title 'Premium API Access' is generic and does not describe the endpoint's actual function
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/products/99/inventory
- —The platform charges $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/products/99/inventory