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 wall. The specific resource `/api/v1/stripe/invoices/51` appears to be a Stripe invoice-related API endpoint, though the exact functionality is not documented beyond the generic label. Payment is settled on the Base network using USDC (contract 0x8335…2913) via the x402 "exact" scheme.
The x402 challenge advertises a maxAmountRequired of 20,000 base units. Since USDC uses 6 decimals, this converts to $0.02 per request, consistent with the site's advertised flat pricing of $0.02/request across all endpoints. The provider markets itself as offering no API keys, no rate limits, and instant access — you simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform lists endpoints across 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. However, documentation beyond the landing page is essentially empty (all subpages just show "Connect wallet"), so the actual behavior, request schemas, and response formats for this specific invoice endpoint are unknown.
Capabilities
Use cases
- —Programmatically accessing Stripe invoice data via a pay-per-call model
- —Agent-driven invoice retrieval without traditional API key management
- —Integrating invoice lookups into crypto-native workflows on Base
Fit
Best for
- —Developers wanting keyless, pay-per-request access to invoice data
- —AI agents that can settle x402 payments on Base in USDC
- —Projects needing low-friction API access without subscription commitments
Not for
- —Users who need detailed API documentation or response schema guarantees 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/51 \
-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/request in USDC on Base). However, there is no documentation for this specific endpoint — no request schema, no response schema, no examples. All doc/pricing/API subpages return only "Connect wallet" with no content. The purpose of the /stripe/invoices/51 resource is entirely opaque.
Warnings
- —No documentation available — all subpages (docs, api, pricing, README) render only 'Connect wallet' with no content
- —The specific functionality of /api/v1/stripe/invoices/51 is undocumented; 'Premium API Access' is a generic label
- —No request or response schema provided; integration requires trial-and-error
- —No OpenAPI spec, no ai-plugin manifest, no agents.txt found
Citations
- —x402 challenge returns maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/stripe/invoices/51
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/stripe/invoices/51
- —Site advertises $0.02/request flat pricing with no API keys, no rate limits, instant accesshttps://lowpaymentfee.com
- —Documentation subpages (docs, api, pricing, README) contain only 'Connect wallet' texthttps://lowpaymentfee.com/docs