x402-gated premium API access on Base, paid per-request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 payment wall. The specific resource path (`/api/v1/stripe/invoices/91`) suggests an invoice-related or Stripe-integration endpoint, though the crawled site documentation does not describe this particular route in detail. The endpoint is live and returns a standard x402 challenge requesting payment in USDC on the Base network.
The x402 challenge specifies a maxAmountRequired of 20,000 base units of USDC (which uses 6 decimals), equating to $0.02 per request. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using the "exact" scheme. The endpoint accepts POST requests and returns application/json. The site advertises a uniform $0.02/request pricing model across all its APIs with no API keys, no rate limits, and instant access.
The broader lowpaymentfee.com platform offers multiple API categories including Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure utilities. However, the specific functionality behind this particular invoice endpoint is not documented in the crawled pages. The docs, pricing, and API pages all appear to require wallet connection and yielded no additional content.
Capabilities
Use cases
- —Programmatic access to a Stripe invoice resource via x402 micropayment
- —Agent-driven API consumption without traditional API key management
- —Pay-per-request access to premium data without subscriptions
Fit
Best for
- —Developers wanting keyless, pay-per-call API access
- —AI agents that can settle x402 payments in USDC on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed documentation or OpenAPI specs before integrating
- —Applications requiring free or high-volume bulk access at discounted rates
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/91 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but the specific functionality of this invoice endpoint is undocumented. No OpenAPI schema, no request/response examples, and the docs/pricing/API pages are empty beyond a wallet-connect prompt. The listing is effectively a stub with pricing info only.
Warnings
- —The specific endpoint /api/v1/stripe/invoices/91 is not described anywhere in the crawled site documentation.
- —Docs, pricing, and API pages returned no meaningful content (only 'Connect wallet').
- —No OpenAPI spec or request/response schema is available.
- —The exact data returned by this endpoint is unknown — 'Premium API Access' is a generic label.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/91
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/stripe/invoices/91
- —Site advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com