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 portfolio ID 91. It is part of a broader platform (lowpaymentfee.com) that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities — all gated behind the x402 payment protocol on the Base network.
The specific endpoint `/api/v1/portfolios/91/holdings` accepts POST requests and is priced at a maximum of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02 per call. Payment is settled on-chain via the x402 "exact" scheme, meaning the caller includes an X-PAYMENT header with a signed payment proof. No API keys, subscriptions, or rate limits are advertised — access is purely pay-per-request.
Documentation on the site is extremely thin: the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no example payloads available. The endpoint is confirmed live (returns a proper 402 challenge), but the actual data returned upon successful payment — field names, structure, portfolio context — is entirely unknown from the available material. Callers should expect a JSON response (mimeType is application/json) but will need to experiment or contact the provider for schema details.
Capabilities
Use cases
- —Fetching current holdings of a specific portfolio on-demand
- —Integrating portfolio data into trading bots or dashboards that support x402 payments
- —Agents autonomously purchasing financial data without API key provisioning
Fit
Best for
- —Developers building on Base who want frictionless pay-per-call portfolio data
- —AI agents with x402-compatible wallets needing portfolio holdings
- —Prototyping financial dashboards without committing to subscription APIs
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Bulk data retrieval where per-request micropayments would be cost-inefficient
- —Anyone needing portfolio IDs other than 91 (no evidence other IDs are available at this path)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/91/holdings \
-H "X-PAYMENT: <x402-payment-header>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The purpose of 'portfolio 91 holdings' is opaque — it could be sample data or a real portfolio. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No request body schema or response schema provided; callers must guess or reverse-engineer
- —The specific portfolio ID 91 is hardcoded in the path with no explanation of what it represents
- —No OpenAPI or ai-plugin manifest discovered
- —No robots.txt or agents.txt present
Citations
- —Endpoint returns 402 with x402 challenge advertising 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/91/holdings
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/91/holdings
- —Platform advertises $0.02 per request, no API keys, no rate limits, Base networkhttps://lowpaymentfee.com