Portfolio holdings data via x402 micropayment on Base network, $0.02 per request.
What it does
This endpoint at lowpaymentfee.com returns portfolio holdings data for a specific portfolio (portfolio ID 5) behind an x402 paywall. It is part of a broader platform offering data & analytics, AI/ML inference, finance/Web3, and infrastructure utility APIs, all priced at $0.02 per request and settled in USDC on the Base network.
The endpoint accepts POST requests and returns JSON. Payment is handled via the x402 protocol: callers receive a 402 challenge specifying the USDC asset on Base (contract 0x8335…2913), with a maxAmountRequired of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). There are no API keys, no rate limits, and no signup required — access is granted instantly upon valid payment. The payment recipient address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 and the timeout window is 300 seconds.
Documentation on the site is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no example payloads available. The exact structure of the holdings response and what input parameters the POST body expects are unknown. The endpoint is confirmed live (402 challenge captured), but without documentation it is difficult to use programmatically without experimentation.
Capabilities
Use cases
- —Retrieving holdings data for a specific investment portfolio
- —Integrating portfolio position data into dashboards or trading bots
- —Querying portfolio composition without API key signup
Fit
Best for
- —Developers wanting frictionless pay-per-call portfolio data
- —Agents that can settle x402 USDC payments on Base
- —Quick one-off portfolio lookups without account creation
Not for
- —Users needing detailed API documentation or request/response schemas before integrating
- —Bulk or high-frequency data retrieval where per-request fees add up
- —Users without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/5/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation: no OpenAPI spec, no request/response schema, no examples, and all doc pages render only 'Connect wallet'. The purpose ('portfolio holdings') is only inferable from the URL path. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema available — request body format and response structure are completely unknown
- —All documentation pages (/docs, /api, /pricing, /README) are empty beyond a 'Connect wallet' prompt
- —The specific portfolio ID (5) is hardcoded in the URL; it is unclear whether other portfolio IDs exist or how they are discovered
- —No information on what 'holdings' data is actually returned
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/5/holdings
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/5/holdings
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com