Pay-per-call portfolio data endpoint on Base network via x402, settled in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" to portfolio data at the path /api/v1/portfolios/90. It is part of a broader platform offering various pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities—all settled via the x402 protocol on the Base network using USDC.
The x402 challenge confirms the endpoint is live and accepts POST requests. Payment is settled on-chain to a specified address using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base). The maximum amount required per call is 20,000 base units of USDC, which equals $0.02 (USDC uses 6 decimals). The platform advertises no API keys, no rate limits, and instant access with a flat $0.02 per request pricing model.
The specific response schema for /api/v1/portfolios/90 is not documented in the crawled material. The endpoint's description is simply "Premium API Access" and the response MIME type is application/json. The broader site lists many endpoints but provides no detailed documentation for any of them—docs, pricing, and README pages all just show a "Connect wallet" prompt. The exact data returned by this portfolio endpoint is unknown.
Capabilities
Use cases
- —Fetching portfolio data without needing an API key or subscription
- —Programmatic access to portfolio information with per-request USDC micropayments
- —Agent-driven portfolio queries settled on Base L2
Fit
Best for
- —Developers wanting keyless, pay-as-you-go API access
- —AI agents that can settle x402 payments on Base
- —Users who prefer on-chain micropayments over subscriptions
Not for
- —Users needing detailed API documentation before integrating
- —High-volume consumers who want bulk pricing or rate-limit guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/90 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02/request in USDC on Base). However, there is no documentation of request parameters, response schema, or what 'portfolios/90' actually returns. The docs pages are empty stubs.
Warnings
- —No documentation available for this specific endpoint's request or response schema
- —All doc/pricing/README pages return only a 'Connect wallet' prompt with no actual content
- —The purpose and data returned by /api/v1/portfolios/90 is entirely undocumented
- —This endpoint path (/api/v1/portfolios/90) is not listed on the site's main API catalog
Citations
- —The endpoint returns a 402 challenge requiring USDC payment on Base network with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/portfolios/90
- —The platform advertises $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/90