Pay-per-call portfolio holdings API on Base, settled in USDC via x402.
What it does
This endpoint at lowpaymentfee.com exposes portfolio holdings data at `/api/v1/portfolios/43/holdings`. It is part of a broader platform offering data & analytics, AI/ML, finance/Web3, and infrastructure APIs, all payable per-request via the x402 protocol on the Base network using USDC.
The specific endpoint returns holdings information for portfolio ID 43. Payment is handled inline: callers attach an X-PAYMENT header with a valid x402 payment proof. The x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The platform advertises uniform $0.02/request pricing across all endpoints, with no API keys, no rate limits, and no minimum commitments.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional content. There is no OpenAPI schema, no request/response examples, and no description of what fields the holdings response contains. The endpoint accepts POST requests based on the outputSchema in the x402 challenge. Without documentation or sample payloads, the exact request body format and response structure remain unknown.
Capabilities
Use cases
- —Retrieving holdings data for a specific portfolio via a single paid API call
- —Integrating portfolio data into agent workflows without API key management
- —Programmatic access to portfolio composition data settled on Base L2
Fit
Best for
- —Agents needing on-demand portfolio holdings without subscription commitments
- —Developers experimenting with x402 pay-per-call patterns
- —Lightweight integrations where API key management is undesirable
Not for
- —Users needing detailed API documentation or response schema guarantees
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone requiring holdings for arbitrary portfolio IDs (only portfolio 43 is confirmed)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/43/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no documentation, no OpenAPI schema, no request/response examples, and the docs pages are empty. The purpose of 'portfolio 43 holdings' is opaque without further context.
Warnings
- —No API documentation available — docs, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request body or response format
- —The specific resource (portfolio 43) is unexplained; unclear if other portfolio IDs are accessible
- —Response content and data freshness are completely unknown
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/43/holdings
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/43/holdings