x402-gated Stripe invoice endpoint on Base, paying per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a Stripe invoice resource (invoice ID 34) behind an x402 paywall. The x402 challenge confirms the endpoint is live and accepts payment in USDC on the Base network using the "exact" scheme. The maximum amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02 per request.
The broader lowpaymentfee.com platform advertises a suite of APIs spanning data & analytics, AI & machine learning (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments. However, the specific endpoint being listed here (/api/v1/stripe/invoices/34) is not among the publicly documented API categories on the landing page, and its exact functionality is unclear — the description simply reads "Premium API Access."
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available. The endpoint accepts POST requests and returns application/json, but the request body schema and response format are unknown.
Capabilities
Use cases
- —Accessing a Stripe invoice resource via programmatic x402 payment
- —Demonstrating x402 protocol integration for pay-per-call APIs
- —Agent-driven invoice retrieval with on-chain USDC settlement
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —Agents that need to fetch invoice data without API key registration
- —Low-cost per-request access without subscription commitments
Not for
- —Users needing well-documented APIs with clear request/response schemas
- —Production workloads requiring SLA guarantees or support
- —Anyone looking for the broader AI/analytics endpoints (those are separate URLs)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/34 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) with clear pricing ($0.02 USDC on Base), but there is no documentation, no OpenAPI spec, no request/response examples, and the specific endpoint's purpose ("Premium API Access" for a Stripe invoice) is vague and not described on the landing page.
Warnings
- —No OpenAPI spec or schema documentation available
- —The /docs, /pricing, /api, and /README pages are empty (only show 'Connect wallet')
- —The specific endpoint /api/v1/stripe/invoices/34 is not listed among the platform's advertised APIs
- —Request body format and response schema are completely unknown
- —Endpoint purpose ('Premium API Access') is generic and uninformative
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/34
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform advertises APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/stripe/invoices/34