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 ID 73. 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 data, and utility services — all gated behind the x402 payment protocol on the Base network.
The specific endpoint `/api/v1/portfolios/73/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 made via the x402 exact-payment scheme: callers attach an `X-PAYMENT` header with a signed payment to the specified payTo address. No API keys, accounts, or rate limits are advertised — access is purely payment-gated.
Documentation on the site is extremely thin. The docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is unclear what request body the POST expects or what shape the holdings response takes. The endpoint appears to be one of many on a platform designed to demonstrate low-fee x402 micropayments.
Capabilities
Use cases
- —Fetching holdings data for a specific portfolio via micropayment
- —Integrating portfolio data into an agent workflow without API key management
- —Demonstrating x402 payment-gated API consumption on Base
Fit
Best for
- —Agents needing on-demand portfolio holdings without subscription commitments
- —Developers experimenting with x402 micropayment protocol on Base
- —Low-volume, pay-as-you-go portfolio data retrieval
Not for
- —Users needing detailed API documentation or guaranteed response schemas
- —High-volume portfolio analytics requiring bulk or batch endpoints
- —Users without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/73/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"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 73 is unexplained. 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 documented; callers must guess the POST payload
- —The specific portfolio ID 73 is hardcoded in the URL with no explanation of what it represents
- —Platform appears to be a demonstration or showcase site for low-fee x402 payments; data quality/reliability is unknown
Citations
- —Endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/73/holdings
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/73/holdings
- —Platform advertises $0.02 per request, no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com