x402-gated Stripe invoice endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com exposes a Stripe invoice resource (`/api/v1/stripe/invoices/94`) behind an x402 paywall. When called without payment, it returns a 402 challenge requesting USDC on the Base network. The endpoint accepts POST requests and returns JSON.
The specific endpoint listed here appears to be a single Stripe invoice lookup (invoice ID 94), which is distinct from the broader suite of APIs advertised on the lowpaymentfee.com homepage (analytics, AI/ML, finance, infrastructure utilities). The site advertises a flat $0.02 per request across all its endpoints, with no API keys, no rate limits, and instant access. The x402 challenge for this particular endpoint specifies a maxAmountRequired of 20,000 base units of USDC (which has 6 decimals), equating to $0.02 per call — consistent with the site's stated pricing.
Payment settles on the Base L2 network to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the USDC contract at `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`. The challenge uses the "exact" payment scheme with x402 version 1 and a 300-second timeout. Documentation on the site is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawled material.
Capabilities
Use cases
- —Retrieving Stripe invoice data via a single paid API call
- —Agent-driven invoice lookups without API key management
- —Programmatic access to invoice records settled in USDC on Base
Fit
Best for
- —Agents that need one-off invoice data without subscription overhead
- —Developers testing x402 payment flows on Base
- —Crypto-native applications needing Stripe invoice integration
Not for
- —Bulk invoice processing requiring thousands of calls (no documented batch support)
- —Users who need detailed API documentation or OpenAPI specs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/94 \
-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 no examples. The specific purpose of this invoice endpoint (ID 94) is unclear — it may be a demo or a specific resource. Effectively a stub listing.
Warnings
- —No OpenAPI spec or request/response schema available
- —Documentation pages (docs, API, pricing, README) all render only 'Connect wallet' with no content
- —The endpoint targets a specific invoice ID (94); unclear if this is a demo or a real resource
- —No examples of successful responses available from crawled material
Citations
- —The x402 challenge requests 20,000 base units of USDC (=$0.02) on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/94
- —The site advertises $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/stripe/invoices/94