Pay-per-call portfolio holdings API on Base via x402, settled in USDC.
What it does
This endpoint at lowpaymentfee.com exposes portfolio holdings data at `/api/v1/portfolios/31/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 probed returns a 402 challenge requesting up to $0.02 per call (20,000 base units of USDC with 6 decimals = $0.02), consistent with the site's advertised flat $0.02/request pricing. Payment is made via the x402 "exact" scheme to a designated wallet address, with a 300-second timeout. The endpoint accepts POST requests and returns `application/json`.
The platform advertises no API keys, no rate limits, and instant access. However, documentation pages (`/docs`, `/pricing`, `/api`, `/README`) all resolve to a minimal "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no description of what fields the holdings response contains. The endpoint is live (402 challenge confirmed), but the lack of documentation makes it difficult to know what data is actually returned or what POST body (if any) is expected.
Capabilities
Use cases
- —Retrieving holdings data for a specific portfolio via a pay-per-call model
- —Integrating portfolio data into agent workflows without managing API keys
- —Programmatic access to financial holdings with USDC micropayments
Fit
Best for
- —Agents or bots that need on-demand portfolio holdings without subscription commitments
- —Developers experimenting with x402 pay-per-call patterns on Base
- —Low-volume consumers who prefer per-request billing over monthly plans
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone requiring non-USDC or non-Base-network payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/31/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI schema, no documentation of request parameters or response format, and all doc pages are empty stubs. The specific data returned by this holdings endpoint is entirely unknown.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all return only a 'Connect wallet' prompt with no content.
- —No OpenAPI or request/response schema provided; request body format and response fields are unknown.
- —The endpoint path includes a hardcoded portfolio ID (31); it is unclear whether other portfolio IDs are accessible or what they represent.
- —Platform appears to be a generic multi-category API storefront; the actual data sources and reliability are unverified.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/31/holdings
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/31/holdings
- —Documentation pages (/docs, /pricing, /api, /README) contain only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs