Retrieve portfolio holdings via x402 micropayment on Base for $0.02 per request.
What it does
This endpoint at lowpaymentfee.com returns holdings data for a specific portfolio (portfolio ID 10) behind an x402 paywall. The payment is settled in USDC on the Base network at $0.02 per request (maxAmountRequired of 20,000 base units with 6 decimals). No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The endpoint accepts POST requests and returns application/json. Based on the URL structure (`/api/v1/portfolios/10/holdings`), it likely returns a list of asset holdings within a given portfolio, though no response schema or example is documented. The provider site (lowpaymentfee.com) hosts a broad catalog of x402-gated APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services, all priced at $0.02 per call.
Documentation is extremely sparse — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema beyond the x402 challenge's outputSchema stub, and no example payloads. The endpoint is confirmed live (402 challenge captured), but the actual data source and response format remain unknown.
Capabilities
Use cases
- —Fetching current holdings for a tracked investment portfolio
- —Building portfolio dashboards that pay per data refresh
- —Agent-driven portfolio monitoring without API key management
Fit
Best for
- —Agents needing on-demand portfolio holdings data with no signup
- —Micropayment-based access to financial data on Base network
- —Developers prototyping x402 payment flows against a live endpoint
Not for
- —Bulk historical portfolio data retrieval (no batch or streaming support documented)
- —Users who need detailed API documentation or guaranteed SLAs
- —Non-crypto-native callers who cannot produce x402 payment headers
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/10/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, but documentation is essentially nonexistent — no request/response schema, no examples, and all doc pages render only a wallet-connect prompt. The purpose of the endpoint is inferred solely from the URL path.
Warnings
- —No OpenAPI spec or response schema available
- —All documentation pages (docs, pricing, API, README) render only 'Connect wallet' with no technical content
- —Request body format and response structure are completely undocumented
- —The specific portfolio ID (10) is hardcoded in the URL; it is unclear whether other portfolio IDs are accessible or what data source backs this
Citations
- —Endpoint returns 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/10/holdings
- —maxAmountRequired is 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), equaling $0.02https://lowpaymentfee.com/api/v1/portfolios/10/holdings
- —Provider advertises $0.02 per request, no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com