x402-gated card-transactions endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com exposes a POST resource at `/api/v1/cards/15/transactions` behind an x402 payment challenge. The x402 challenge indicates the endpoint accepts exact-scheme payments on the Base network using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) with a maximum amount of 20,000 base units, which equals $0.02 USD (USDC uses 6 decimals). The endpoint is described by the provider simply as "Premium API Access" with no further documentation on what data it returns or what input it expects.
The broader lowpaymentfee.com platform advertises a suite of x402-gated APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request with no API keys, no rate limits, and instant access via the Base network. However, the specific `/api/v1/cards/15/transactions` path does not appear in the site's listed API catalog, and no documentation, schema, or example payloads are available for it. The docs, API, pricing, and README pages all resolve to a minimal "Connect wallet" prompt with no substantive content.
Without request/response schemas or documentation, the actual functionality of this endpoint is unknown. The path suggests it may relate to card transaction data for a specific card (ID 15), but this is speculative. Agents should be aware that the endpoint is live (returning a valid 402 challenge) but its behavior after payment is undocumented.
Capabilities
Use cases
- —Retrieving transaction data for a specific card via pay-per-call USDC payments
- —Programmatic access to card transaction records without API key registration
- —Agent-driven financial data retrieval settled on Base L2
Fit
Best for
- —Developers wanting keyless, pay-per-call access to card transaction data
- —AI agents with USDC on Base that need on-demand financial endpoints
- —Prototyping x402 payment flows against a live endpoint
Not for
- —Production use requiring documented request/response schemas
- —Users needing bulk or subscription-based access to transaction data
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/15/transactions
# Returns 402 with x402 challenge; attach X-PAYMENT header with valid USDC payment to access.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no request/response schema, no examples, and the specific path is not listed in the provider's own API catalog. Functionality is entirely unknown beyond the path name hint.
Warnings
- —No request or response schema available — endpoint behavior after payment is unknown
- —This specific path (/api/v1/cards/15/transactions) is not listed in the provider's public API catalog
- —All documentation pages (docs, API, pricing, README) contain only a 'Connect wallet' prompt with no content
- —The 'cards/15' path segment suggests a hardcoded resource ID; generalizability is unclear
Citations
- —The x402 challenge requires USDC on Base with maxAmountRequired of 20000 base units ($0.02)https://lowpaymentfee.com/api/v1/cards/15/transactions
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Basehttps://lowpaymentfee.com
- —The provider lists APIs across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages resolve to minimal 'Connect wallet' contenthttps://lowpaymentfee.com/docs