x402-gated premium API access on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol on the Base network. The specific resource `/api/v1/portfolios/95` is one of many endpoints offered by the platform, which spans categories including data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, payable in USDC (USD Coin) on Base, with no API keys, rate limits, or commitments required.
The x402 challenge confirms the endpoint is live and accepts POST requests. Payment is settled on-chain to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC at contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`. The max amount required is 20,000 base units, which equals $0.02 (USDC uses 6 decimals). The response MIME type is `application/json`.
However, the specific functionality of the `/api/v1/portfolios/95` endpoint is unclear. The landing page does not list a "portfolios" category, and no documentation, request schema, or response schema is available for this particular route. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional content. Without knowing what data or service this endpoint returns, consumers should treat this as an exploratory or undocumented endpoint.
Capabilities
Use cases
- —Accessing portfolio data behind a per-request USDC paywall
- —Agent-driven API consumption without API key management
- —Micropayment-gated data retrieval on Base L2
Fit
Best for
- —Agents or services that can settle x402 payments in USDC on Base
- —Use cases requiring keyless, pay-per-call API access
- —Developers exploring x402 protocol integrations
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Applications requiring free or subscription-based access patterns
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/95 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no request/response schema, and the specific purpose of /api/v1/portfolios/95 is not described anywhere on the site. The docs pages are empty (wallet-connect only). This is effectively a stub listing.
Warnings
- —The /api/v1/portfolios/95 path is not listed among the site's advertised endpoints — its purpose is unknown.
- —All documentation pages (docs, API, pricing, README) render only a 'Connect wallet' prompt with no usable content.
- —No request or response schema is available for this endpoint.
- —The platform appears to be a generic demo or template site — many listed endpoints may not return meaningful data.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/95
- —All endpoints are priced at $0.02 per request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/95
- —The site lists categories: Data & Analytics, AI & Machine Learning, Finance & Web3, Infrastructurehttps://lowpaymentfee.com