x402-gated Stripe invoice endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 payment challenge. It is part of a broader platform that offers a variety of pay-per-request APIs spanning data & analytics, AI/ML inference, finance & Web3 data, and infrastructure utilities — all gated via the x402 protocol on the Base network and settled in USDC.
The specific endpoint `/api/v1/stripe/invoices/18` appears to be a Stripe invoice-related resource. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0x8335…on Base), which equals $0.02 per request (USDC uses 6 decimals). The platform advertises flat $0.02/request pricing across all endpoints with no API keys, no rate limits, and instant access. Payment is made via the x402 exact scheme, settling on the Base L2 network.
Documentation on the site is extremely thin — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed description of what this particular invoice endpoint returns or what input it expects. The endpoint accepts POST requests and returns application/json according to the outputSchema. Without further documentation, the actual functionality of this specific endpoint remains unclear beyond its name.
Capabilities
Use cases
- —Retrieving Stripe invoice data via a single paid API call
- —Programmatic access to invoice information without traditional API key management
- —Agent-driven invoice lookups settled in USDC on Base
Fit
Best for
- —Developers who want keyless, pay-per-use API access
- —AI agents with USDC on Base that need invoice data
- —Quick one-off invoice lookups without subscription commitments
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume invoice processing where $0.02/call adds up significantly
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/18 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages return only a wallet-connect prompt. The actual functionality of this specific invoice endpoint is unclear.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided
- —The purpose and expected input/output of /api/v1/stripe/invoices/18 is not documented
- —No examples of successful responses available
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/18
- —Platform advertises $0.02/request flat pricing 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/18