x402-gated Stripe invoice endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a specific Stripe invoice resource (invoice ID 44) behind an x402 paywall. The site advertises itself as a platform hosting multiple pay-per-request API categories including data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all gated via the x402 protocol on the Base network using USDC.
The specific endpoint `/api/v1/stripe/invoices/44` is labeled "Premium API Access" and returns a valid x402 challenge when called via POST. The challenge specifies payment in USDC (contract 0x8335…) on Base to address 0x1A2B…, with a maximum amount of 20,000 base units. Since USDC uses 6 decimals, this translates to $0.02 per request — consistent with the site's advertised flat pricing of $0.02/request across all endpoints. The endpoint accepts POST requests and returns application/json.
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 spec, no request/response schema documentation, and no explanation of what data this particular invoice endpoint actually returns. The site's landing page lists many API categories but provides no detail on input parameters or response formats for any of them. The actual utility of this specific Stripe invoices endpoint is unclear from available materials.
Capabilities
Use cases
- —Retrieving Stripe invoice data via a single paid API call
- —Programmatic access to invoice information without API key management
- —Agent-driven invoice lookup with automatic USDC micropayment
Fit
Best for
- —Agents needing keyless, pay-per-call access to invoice data
- —Developers exploring x402 payment protocol integrations
- —Use cases requiring no subscription or rate-limit constraints
Not for
- —Production invoice management requiring documented schemas and SLAs
- —Bulk invoice retrieval where per-call pricing would be cost-prohibitive
- —Users who need detailed API documentation before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/44
# Returns 402 with x402 challenge; attach X-PAYMENT header with USDC payment proof on Base to access.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, and all documentation pages are empty beyond a wallet-connect prompt. The purpose of this specific Stripe invoice endpoint is unexplained, making it effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages are all empty
- —No OpenAPI or schema definition for request parameters or response format
- —The specific purpose and data returned by /api/v1/stripe/invoices/44 is undocumented
- —Site lists many endpoint categories but none appear to have detailed docs
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/stripe/invoices/44
- —The site advertises $0.02/request flat pricing across all endpoints with no API keys, no rate limitshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/44