x402-gated Stripe invoice endpoint on Base, paying per-call in USDC.
What it does
This endpoint at lowpaymentfee.com exposes a specific Stripe invoice resource (`/api/v1/stripe/invoices/143`) behind an x402 paywall. The provider operates a broader platform offering dozens of pay-per-call APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services — all settled on the Base network using USDC via the x402 protocol.
The probed endpoint returns a valid x402 challenge (version 1, scheme "exact") requesting up to 20,000 base units of USDC (0x8335…) on Base. 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. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The specific purpose of this particular endpoint — retrieving or interacting with Stripe invoice #143 — is not documented beyond the generic label "Premium API Access." The provider's documentation pages (docs, pricing, README) all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawled material. The broader site lists categories like sentiment analysis, text summarization, geocoding, and price feeds, but this specific invoice endpoint does not appear in those listings, suggesting it may be a specialized or internal resource.
Capabilities
Use cases
- —Programmatically accessing a specific Stripe invoice via a crypto-settled paywall
- —Agent-driven retrieval of invoice data without traditional API keys
- —Demonstrating x402 payment flows for per-call billing
Fit
Best for
- —Agents or services that can settle USDC payments on Base
- —Developers exploring x402 protocol integrations
- —Scenarios requiring keyless, pay-per-use API access
Not for
- —Users needing detailed invoice management or bulk Stripe operations
- —Anyone without a Base-compatible USDC wallet
- —Use cases requiring documented request/response schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/143 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"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, no documentation beyond a wallet-connect prompt, and the specific purpose of this invoice endpoint is unclear. Effectively a stub listing.
Warnings
- —No OpenAPI or request/response schema available for this endpoint
- —Documentation pages (/docs, /pricing, /README) render only 'Connect wallet' with no technical content
- —The specific endpoint /api/v1/stripe/invoices/143 is not listed among the provider's advertised APIs — its purpose is unclear
- —No examples of successful responses are available
Citations
- —The x402 challenge requests up to 20,000 base units of USDC on Base with a 300-second timeouthttps://lowpaymentfee.com/api/v1/stripe/invoices/143
- —The provider advertises $0.02/request flat pricing with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/stripe/invoices/143