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 91) 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 using USDC.
The specific endpoint `/api/v1/products/91/inventory` is listed as "Premium API Access" and accepts POST requests. Payment is settled on-chain on Base using USDC (contract 0x8335…2913) with a maximum amount of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals). The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
Documentation is extremely sparse. The docs, pricing, API, and README pages all render 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 endpoint actually returns. The endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is unclear what input the POST body should contain or what shape the response takes.
Capabilities
Use cases
- —Querying product inventory data with per-request USDC micropayments
- —Integrating inventory checks into agent workflows without API key management
- —Programmatic inventory lookups settled on Base L2
Fit
Best for
- —Developers or agents wanting keyless, pay-per-call inventory data
- —x402-compatible agent wallets on Base network
- —Low-friction API access without subscriptions or rate limits
Not for
- —Users needing detailed API documentation or schema before integrating
- —High-volume use cases where per-request pricing may add up
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/91/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what 'Premium API Access' for product 91 inventory actually returns. The listing is effectively a stub.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema describing request body or response format
- —The specific purpose and data returned by /api/v1/products/91/inventory is unknown
- —Cannot verify what 'Premium API Access' actually provides beyond the endpoint being live
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/products/91/inventory
- —The platform advertises $0.02 per request, no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/products/91/inventory
- —Docs, pricing, API, and README pages render only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs