x402-gated Stripe invoice endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a Stripe invoice resource (invoice ID 64) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) via the x402 "exact" scheme. The maximum amount required per call is 20,000 base units of USDC, which equals $0.02 (USDC uses 6 decimals).
The hosting site lowpaymentfee.com advertises a broad catalog of pay-per-request APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/crypto data feeds, and utility services — all priced at $0.02 per request with no API keys, no rate limits, and no commitments. However, the specific endpoint listed here (/api/v1/stripe/invoices/64) is not among the APIs advertised on the landing page, and its exact functionality is unclear. The description simply reads "Premium API Access," which is generic and uninformative.
The x402 challenge was successfully captured (HTTP 402 with valid accepts array), confirming the endpoint is live. No OpenAPI schema, detailed documentation, or example request/response payloads are available — the docs, pricing, API, and README pages all returned only a "Connect wallet" prompt with no substantive content. Without documentation or schema details, the actual input parameters and response format for this invoice endpoint remain unknown.
Capabilities
Use cases
- —Retrieving or interacting with Stripe invoice data via a crypto-paywall
- —Programmatic access to invoice information without traditional API keys
- —Agent-driven payment and data retrieval in a single HTTP round-trip
Fit
Best for
- —Developers wanting keyless, pay-per-call access to invoice data
- —AI agents that can settle x402 payments on Base with USDC
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or schema before integrating
- —High-volume invoice processing where $0.02/call adds up significantly
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/invoices/64
# Returns 402 with x402 challenge; attach X-PAYMENT header with valid USDC payment proof on Base to access.Endpoint
Quality
The endpoint is live (valid 402 challenge captured), but there is no OpenAPI schema, no documentation, no example requests or responses, and the endpoint path (/api/v1/stripe/invoices/64) is not listed among the site's advertised APIs. The description 'Premium API Access' is generic and uninformative. Effectively a stub listing.
Warnings
- —The specific endpoint /api/v1/stripe/invoices/64 is not listed among the site's advertised APIs — its purpose is unclear.
- —No documentation, OpenAPI spec, or example payloads are available; all doc pages returned only 'Connect wallet'.
- —The description 'Premium API Access' is generic and does not explain what this endpoint actually does.
- —The endpoint references a Stripe invoice by ID (64), which may be a static or demo resource rather than a general-purpose API.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/64
- —USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/stripe/invoices/64
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Docs, pricing, API, and README pages all returned only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs