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 17) behind an x402 paywall. The provider operates a broad catalog of pay-per-call APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services, all settled on the Base network using USDC.
The specific endpoint `/api/v1/products/17/inventory` is listed as "Premium API Access" and accepts POST requests. Payment is handled via the x402 protocol: callers receive a 402 challenge with payment parameters, settle on-chain in USDC on Base, and then gain access to the response. The maximum amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02 USD. The provider advertises a flat $0.02/request price across all endpoints, no API keys, no rate limits, and instant access.
Documentation is extremely thin — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no examples available. The actual data returned by this inventory endpoint is unknown beyond the stated mime type of `application/json`. Prospective callers should be aware that the endpoint's behavior and response format are not documented.
Capabilities
Use cases
- —Querying product inventory data with per-request USDC micropayments
- —Integrating pay-per-call inventory checks into automated agent workflows
- —Accessing premium product data without API key registration
Fit
Best for
- —Agents or services that can settle x402 payments on Base in USDC
- —Use cases requiring keyless, per-request API access
- —Low-volume or sporadic inventory lookups where subscription pricing is wasteful
Not for
- —Users who need detailed API documentation or response schema guarantees before integrating
- —High-volume inventory queries where per-request pricing at $0.02 adds up significantly
- —Users without a Base-compatible USDC wallet
Quick start
# 1. Send POST to get the 402 challenge
curl -X POST https://lowpaymentfee.com/api/v1/products/17/inventory
# Returns 402 with x402 payment challenge (USDC on Base, $0.02)
# 2. Settle payment on-chain, then resend with X-PAYMENT header
curl -X POST https://lowpaymentfee.com/api/v1/products/17/inventory \
-H "X-PAYMENT: <signed-payment-token>"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 docs pages are empty beyond a wallet-connect prompt. The purpose of 'product 17 inventory' is opaque.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition for request or response payloads
- —The specific meaning of 'products/17/inventory' is undocumented; actual response structure is unknown
- —Provider appears to be a demo or early-stage platform with many listed endpoints but no substantive documentation
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/products/17/inventory
- —The provider advertises $0.02/request pricing across all endpoints with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/products/17/inventory
- —Docs, pricing, API, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs