Retrieve portfolio holdings data via x402 micropayment on Base (USDC, $0.02/request).
What it does
This endpoint at lowpaymentfee.com returns holdings data for portfolio ID 19. It is part of a broader platform offering pay-per-request APIs across data analytics, AI/ML, finance/Web3, and infrastructure categories — all settled via the x402 protocol on the Base network using USDC.
The endpoint accepts POST requests and returns JSON. Payment is handled inline via the X-PAYMENT header using the x402 "exact" scheme. The maximum amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02 USD. No API keys, rate limits, or upfront commitments are needed; callers simply attach a valid x402 payment header to each request.
The specific data returned by the /portfolios/19/holdings endpoint is not documented in detail. The provider's landing page lists this endpoint under a generic "Premium API Access" label without describing the response schema or the nature of portfolio 19. Other endpoints on the same platform cover analytics, AI inference, finance data, and utility services, all at the same $0.02 price point. Because the crawled docs pages returned only a "Connect wallet" prompt with no further content, the actual request body format and response fields remain unknown.
Capabilities
Use cases
- —Fetching holdings data for a specific portfolio via automated agent
- —Integrating pay-per-call portfolio data into a trading or analytics pipeline
- —Demonstrating x402 micropayment protocol usage on Base network
Fit
Best for
- —Agents that need on-demand portfolio holdings without managing API keys
- —Developers experimenting with x402 micropayment-gated APIs
- —Low-volume consumers who prefer per-request pricing over subscriptions
Not for
- —Users needing detailed API documentation or response schema guarantees before integrating
- —High-frequency bulk data consumers who need subscription-based pricing
- —Anyone requiring non-USDC or non-Base-network payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/19/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_header>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation of request body format, response schema, or what portfolio 19 actually represents. Docs pages returned only 'Connect wallet' with no usable content.
Warnings
- —No documentation available — all doc/pricing/API pages return only a 'Connect wallet' prompt with no content.
- —The nature of portfolio 19 and the structure of the holdings response are completely undocumented.
- —Request body schema is unknown; no OpenAPI spec or examples are provided.
- —The platform lists many diverse endpoints (AI, finance, utilities) all at $0.02 — unclear whether all are fully functional or placeholders.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/19/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
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/19/holdings