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 #77 via a POST request, gated by the x402 payment protocol. Each call costs $0.02 in USDC on the Base network — the x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (6 decimals), which equals $0.02. No API keys or rate limits are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The provider site (lowpaymentfee.com) hosts a broad catalog of pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3 market data, and utility services, all priced at $0.02 per request. This specific endpoint falls under the finance category and appears to serve portfolio-level holdings information, though the exact response schema is not documented. The payment settles to address 0x1A2B…85F3 using USDC (contract 0x8335…2913) on Base.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no additional technical content. There is no OpenAPI spec, no example request/response payloads, and no description of what fields the holdings response contains. The endpoint is confirmed live (402 challenge captured), but without documentation it is difficult to know what POST body to send or what shape the response takes.
Capabilities
Use cases
- —Fetching current holdings for a specific portfolio programmatically
- —Integrating portfolio data into automated trading or rebalancing agents
- —Building dashboards that display portfolio composition without managing API keys
Fit
Best for
- —Agents needing on-demand portfolio holdings without subscription commitments
- —Developers who prefer crypto micropayments over traditional API key management
- —Low-volume or sporadic access to portfolio data at $0.02 per call
Not for
- —Users who need detailed API documentation or response schema guarantees before integrating
- —High-frequency polling where per-request costs would accumulate significantly
- —Anyone without a Base-network USDC wallet or x402-compatible client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/77/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no documented request/response schema, no examples, and all documentation pages return only a wallet-connect prompt. The purpose of this specific endpoint (portfolio 77 holdings) is only inferable from the URL path.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no technical content
- —No OpenAPI or schema definition for request body or response format
- —The specific portfolio ID (77) is hardcoded in the URL; unclear if other portfolio IDs are accessible or what they represent
- —Response content and fields are entirely unknown — no example responses available
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/77/holdings
- —USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/77/holdings
- —All APIs on the site are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The provider lists finance, AI/ML, data analytics, and infrastructure API categorieshttps://lowpaymentfee.com