x402-gated Stripe invoice endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 payment challenge. The specific resource path (`/api/v1/stripe/invoices/175`) suggests it returns or processes a Stripe invoice identified by ID 175. Payment is settled on the Base network using USDC (contract 0x8335…2913) with a maximum cost of $0.02 per request (20,000 base units at 6 decimals). The endpoint accepts POST requests and returns application/json.
The broader lowpaymentfee.com platform advertises a suite of pay-per-call APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/crypto market data, and infrastructure utilities — all priced at $0.02 per request with no API keys, no rate limits, and no commitments. However, the specific endpoint listed here is under the Stripe invoices path, which is not among the publicly documented API categories on the landing page. This means its exact request/response schema is unknown.
The x402 challenge is live and well-formed (version 1, scheme "exact"), with a 300-second payment timeout. No OpenAPI spec, detailed documentation, or example payloads were found during crawling — the docs, pricing, API, and README pages all rendered only a "Connect wallet" prompt with no additional content. Because of this, the endpoint's actual functionality and response format remain unclear beyond what the x402 challenge metadata reveals.
Capabilities
Use cases
- —Retrieving or processing a specific Stripe invoice via a crypto-paid API call
- —Integrating pay-per-call invoice access into an agent workflow without API keys
- —Demonstrating x402 payment protocol usage on Base with USDC
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —Agents needing keyless, pay-per-call access to invoice data
- —Projects that want to avoid subscription-based API billing
Not for
- —Users needing well-documented, production-grade Stripe invoice APIs
- —Bulk invoice processing requiring high throughput with known SLAs
- —Anyone who needs detailed request/response schema documentation before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/175
# Returns 402 with x402 challenge; include X-PAYMENT header with valid USDC payment proof on Base to access.Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and accepts payment. However, there is no OpenAPI spec, no request/response examples, and the docs pages are empty. The specific invoice endpoint is not listed among the site's publicly advertised APIs, making its purpose and schema unclear.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —Docs, pricing, API, and README pages all render only 'Connect wallet' with no content
- —The /api/v1/stripe/invoices/175 path is not listed among the site's publicly advertised endpoints — its purpose is unclear
- —Exact request body format and response schema are unknown
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units in USDC (6 decimals) = $0.02 on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/175
- —The site advertises all APIs at $0.02/request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Docs, pricing, API, and README pages contain only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs