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 `/api/v1/stripe/invoices/77` appears to be a Stripe invoice-related API call, though the exact functionality (e.g., fetching invoice details, creating invoices) is not documented beyond the generic title. Payment is settled on the Base network using USDC (contract 0x8335…2913) via the x402 "exact" scheme.
The endpoint charges a maximum of 20,000 base units of USDC per request. Since USDC uses 6 decimals, this equals $0.02 per call — consistent with the site-wide pricing of $0.02/request advertised on the landing page. The provider advertises no API keys, no rate limits, and instant access. The x402 challenge specifies a 300-second (5-minute) payment timeout and accepts POST requests.
lowpaymentfee.com hosts a broader catalog of x402-gated APIs spanning data/analytics, AI/ML (sentiment, summarization, classification, embeddings), finance/Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation) — all at the same $0.02/request price point. Documentation pages beyond the landing page returned only a "Connect wallet" prompt with no additional technical detail.
Capabilities
Use cases
- —Fetching or interacting with Stripe invoice data via a crypto-settled pay-per-call model
- —Integrating invoice operations into agent workflows without traditional API key management
- —Programmatic access to Stripe invoice resources settled on Base L2 with USDC
Fit
Best for
- —Developers wanting keyless, pay-per-use access to Stripe invoice functionality
- —AI agents that can settle x402 challenges on Base with USDC
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI schemas before integrating
- —High-volume invoice processing where $0.02/call adds up significantly
- —Anyone requiring non-USDC or non-Base payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/77 \
-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 documentation pages are empty beyond a wallet-connect prompt. The specific functionality of the /stripe/invoices/77 resource is undocumented.
Warnings
- —No API documentation available — all doc pages return only 'Connect wallet' with no technical content
- —The exact purpose and request/response format of /api/v1/stripe/invoices/77 is unknown
- —No OpenAPI spec or input/output schema provided beyond the minimal outputSchema in the x402 challenge
- —The resource path includes a hardcoded ID (77), which may indicate a specific invoice rather than a general endpoint
Citations
- —Endpoint returns a valid x402 challenge with USDC on Base network, maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/stripe/invoices/77
- —Site-wide pricing is $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/stripe/invoices/77