Retrieve portfolio holdings data via x402 micropayment on Base for $0.02 per request.
What it does
This endpoint at lowpaymentfee.com returns holdings data for portfolio ID 75. It is part of a broader platform (lowpaymentfee.com) that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services — all gated behind the x402 payment protocol on the Base network.
The specific endpoint `/api/v1/portfolios/75/holdings` accepts POST requests and is priced at a maximum of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02 per call. Payment is settled on-chain via the x402 "exact" scheme, meaning the caller includes a signed payment in the X-PAYMENT header and receives the JSON response upon verification. No API keys, subscriptions, or rate limits are advertised — access is purely pay-per-request.
Documentation on the site is extremely thin: the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema, and no example payloads available. The endpoint is confirmed live (returns a proper 402 challenge), but the actual structure of the holdings response and the expected POST body are unknown. The portfolio ID 75 is hardcoded in the URL; it is unclear whether other portfolio IDs are available or what data source backs the holdings.
Capabilities
Use cases
- —Fetching current holdings for a specific portfolio via automated agent
- —Integrating portfolio data into dashboards or trading bots without managing API keys
- —Pay-per-call access to financial holdings data settled on Base L2
Fit
Best for
- —Agents or bots that need on-demand portfolio holdings without subscription overhead
- —Developers experimenting with x402 micropayment-gated APIs
- —Crypto-native applications that can sign USDC payments on Base
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —Bulk or high-frequency data retrieval where per-call pricing adds up
- —Anyone without a Base-compatible wallet or USDC balance
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/75/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is zero documentation on request body format, response schema, or what data is actually returned. No OpenAPI spec, no examples, and all doc pages are empty. This is effectively a stub listing.
Warnings
- —No request or response schema available — the POST body format and response structure are completely unknown.
- —All documentation pages (docs, pricing, API, README) render only 'Connect wallet' with no technical content.
- —The portfolio ID 75 is hardcoded; it is unclear what entity or data source this represents.
- —The site lists many other endpoints but this specific holdings endpoint is not listed on the homepage, raising questions about its intended audience.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), equaling $0.02.https://lowpaymentfee.com/api/v1/portfolios/75/holdings
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —Documentation, pricing, API, and README pages all show only a 'Connect wallet' prompt with no additional content.https://lowpaymentfee.com/docs