x402-gated Stripe invoice endpoint on Base, paying $0.02 in USDC per request.
What it does
This endpoint at lowpaymentfee.com provides access to a Stripe invoice resource (invoice ID 171) behind an x402 payment wall. The site advertises itself as a collection of pay-per-request APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per call, settled in USDC on the Base network with no API keys, no rate limits, and no commitments.
The specific endpoint `/api/v1/stripe/invoices/171` is labeled "Premium API Access" and returns a standard x402 challenge (version 1, scheme "exact") requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The endpoint accepts POST requests.
Documentation is extremely sparse — 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, and no explanation of what data the invoice endpoint actually returns. The site's landing page lists many other endpoints across categories (sentiment analysis, text summarization, geocoding, price feeds, etc.), all at the same $0.02 price point, but none have documented schemas either. Treat this listing as a stub until the provider publishes proper documentation.
Capabilities
Use cases
- —Retrieving Stripe invoice data via a single micropayment without API key registration
- —Programmatic access to invoice #171 for automated billing workflows
- —Demonstrating x402 payment protocol integration with USDC on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC on Base for per-call API access
- —Use cases requiring keyless, pay-as-you-go API access
Not for
- —Production workloads requiring documented request/response schemas
- —Users who need bulk or subscription-based invoice retrieval at lower per-unit cost
- —Anyone needing non-crypto payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/171
# Returns 402 with x402 challenge; attach X-PAYMENT header with USDC payment proof to access.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what the endpoint actually returns, no OpenAPI spec, no request body schema, and no response examples. The docs pages are empty. This is effectively a stub listing.
Warnings
- —No OpenAPI or request/response schema available — the actual data returned by this endpoint is unknown.
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no technical content.
- —The endpoint path suggests a single static Stripe invoice resource (ID 171); unclear if this is a demo or production resource.
- —The site lists many other endpoints but none appear to have documentation either.
Citations
- —The endpoint returns an x402 challenge requesting up to 20,000 base units of USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), equaling $0.02.https://lowpaymentfee.com/api/v1/stripe/invoices/171
- —The site advertises all APIs at $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —Documentation pages (docs, API, pricing, README) render only a 'Connect wallet' prompt with no further content.https://lowpaymentfee.com/docs