x402-gated Stripe invoice endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a Stripe invoice resource (invoice ID 199) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) via the x402 "exact" scheme. The maximum amount required per call is 20,000 base units of USDC, which equals $0.02 (USDC uses 6 decimals).
The hosting site lowpaymentfee.com advertises a broader suite of APIs spanning data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation) — all priced at $0.02 per request with no API keys, no rate limits, and instant access. However, this specific listing is for the Stripe invoices endpoint at path /api/v1/stripe/invoices/199, which is not listed on the site's public catalog. Its exact response payload and purpose are unclear from available documentation.
The endpoint is confirmed live: the probe received a proper HTTP 402 x402 challenge with version 1, advertising the USDC payment address and a 300-second timeout. No OpenAPI schema, detailed docs, or example responses were found — the docs, pricing, and README pages all returned only a "Connect wallet" stub.
Capabilities
Use cases
- —Retrieving Stripe invoice data programmatically via a crypto-paid endpoint
- —Agent-driven invoice lookup without traditional API key provisioning
- —Demonstrating x402 payment protocol integration with Stripe billing data
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing on-demand invoice data without API key management
- —Micro-payment use cases where $0.02/call is acceptable
Not for
- —Bulk invoice retrieval at scale (no batch endpoint documented)
- —Users who need detailed API documentation or guaranteed SLAs
- —Non-crypto workflows that require traditional authentication
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/199 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI schema, no documented request/response format, and the docs pages are empty stubs. The specific endpoint (/api/v1/stripe/invoices/199) is not listed in the site's public API catalog, making its purpose and output unclear.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —Docs, pricing, and README pages return only 'Connect wallet' with no content
- —This specific endpoint path (/api/v1/stripe/invoices/199) is not listed in the site's public API catalog
- —Response format and fields are entirely unknown — no example responses available
- —Hardcoded invoice ID (199) in the path suggests this may be a single-resource endpoint rather than a general-purpose API
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/199
- —The site advertises APIs at $0.02/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/199