Pay-per-call portfolio holdings API on Base, settled in USDC via x402.
What it does
This endpoint at lowpaymentfee.com provides access to portfolio holdings data for a specific portfolio (ID 89) via a POST request. It is part of a broader platform offering data & analytics, AI/ML, finance/Web3, and infrastructure APIs, all priced at $0.02 per request with no API keys, no rate limits, and instant access.
Payment is handled via the x402 protocol on the Base network using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). The maximum amount required per call is 20,000 base units of USDC, which equals $0.02 (USDC uses 6 decimals). The endpoint returns application/json and has a payment timeout of 300 seconds.
Documentation is extremely sparse — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further content. The specific request body schema and response format for the holdings endpoint are not documented anywhere in the crawled material. The endpoint is confirmed live, returning a proper 402 x402 challenge, but without documentation it is difficult to know what POST body to send or what the response structure looks like.
Capabilities
Use cases
- —Retrieving holdings data for a specific investment portfolio
- —Integrating portfolio position data into dashboards or analytics tools
- —Agent-driven portfolio monitoring with per-call payment
Fit
Best for
- —Developers needing on-demand portfolio holdings without subscription commitments
- —AI agents that can settle USDC payments on Base via x402
- —Applications requiring low-cost, keyless API access to financial data
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —Bulk or high-frequency data retrieval where per-call pricing adds up
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/89/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no documentation on request body format, response schema, or what 'portfolio 89' represents. Docs pages are empty. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and API pages only show 'Connect wallet'
- —Request body schema for POST is unknown
- —Response schema is unknown
- —The specific portfolio ID (89) is hardcoded in the URL with no explanation of what it represents
- —Cannot verify what data is actually returned without making a paid request
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/89/holdings
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/89/holdings