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 #29) behind an x402 paywall. 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 utility services — all priced at $0.02 per call, settled in USDC on the Base network.
The specific endpoint `/api/v1/stripe/invoices/29` is labeled "Premium API Access" and accepts POST requests. Payment is handled via the x402 protocol: callers receive a 402 challenge containing the payment details (asset, amount, payTo address), construct an on-chain USDC payment on Base, and include the payment proof in the X-PAYMENT header to unlock the response. The max amount required is 20,000 base units of USDC (6 decimals), which equals $0.02. The payment timeout is 300 seconds.
Documentation on the site is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical content. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The actual data returned by this invoice endpoint is unknown beyond the stated mime type of application/json. The platform advertises no API keys, no rate limits, and instant access, but these claims cannot be independently verified from the crawled material.
Capabilities
Use cases
- —Retrieving Stripe invoice data via a single micropayment without API key registration
- —Programmatic access to invoice information for automated billing workflows
- —Agent-driven payment and data retrieval using x402 protocol on Base
Fit
Best for
- —Developers wanting keyless, pay-per-use API access settled in USDC
- —AI agents that can autonomously pay for API calls via x402
- —Users who prefer on-chain micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/29 \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is zero documentation on request/response schemas, no OpenAPI spec, and all doc pages return only a wallet-connect prompt. The purpose of this specific invoice endpoint is unclear beyond its label.
Warnings
- —No OpenAPI spec or request/response schema available
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no content
- —The specific purpose and response format of /api/v1/stripe/invoices/29 is undocumented
- —Cannot verify claims of 'no rate limits' or actual data returned
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/29
- —Platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/stripe/invoices/29
- —Platform offers APIs across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com