Pay-per-call product inventory endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This x402-enabled endpoint at lowpaymentfee.com provides access to product inventory data (specifically for product ID 100) via a POST request. Payment is handled inline using the x402 protocol on the Base network, settling in USDC (contract 0x8335…2913). Each call costs a maximum of 0.02 USDC (20,000 base units with 6 decimals), with no API keys, rate limits, or upfront commitments required.
The endpoint is part of a broader suite of pay-per-call APIs offered by lowpaymentfee.com spanning data & analytics, AI/ML inference, finance & Web3 data, and infrastructure utilities — all priced uniformly at $0.02 per request. The specific endpoint enriched here targets inventory lookup, though the provider's landing page does not list this particular path among its featured APIs, suggesting it may be a demo or ancillary resource.
Documentation is extremely sparse. The /docs, /pricing, /api, and /README pages all resolve to a minimal "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples beyond the x402 challenge itself. The endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is difficult to know what request body to send or what shape the response takes.
Capabilities
Use cases
- —Querying product inventory levels with per-call USDC micropayments
- —Integrating inventory checks into agent workflows without API key management
- —Demonstrating x402 protocol payment flows on Base
Fit
Best for
- —Developers experimenting with x402 pay-per-call patterns
- —Agents needing keyless, on-demand inventory data access
- —Projects already operating on the Base L2 with USDC
Not for
- —Production inventory management requiring documented schemas and SLAs
- —High-volume bulk inventory queries where per-call pricing is inefficient
- —Users without Base network USDC wallets
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/products/100/inventory \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but documentation is essentially nonexistent — no OpenAPI spec, no request/response schemas, no examples. The specific inventory endpoint is not even listed on the provider's own landing page. This is effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all show only a wallet-connect prompt
- —No OpenAPI or request/response schema provided; request body and response format are unknown
- —This specific endpoint (/api/v1/products/100/inventory) is not listed among the provider's advertised APIs
- —Provider appears to be a demo or early-stage project with minimal content
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 in USDC on Base networkhttps://lowpaymentfee.com/api/v1/products/100/inventory
- —All APIs are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/products/100/inventory