Portfolio holdings data via x402 micropayment on Base network for $0.02/request
What it does
This endpoint at lowpaymentfee.com returns portfolio holdings data for portfolio ID 30. 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 market data, and infrastructure utilities — all gated behind the x402 payment protocol on the Base network using USDC.
The specific endpoint `/api/v1/portfolios/30/holdings` accepts POST requests and is priced at a maximum of 20,000 base units of USDC (0.02 USD per request, since USDC uses 6 decimals). Payment is settled on-chain via the Base L2 network to the specified payTo address. No API keys, rate limits, or upfront commitments are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
Documentation on the site is extremely sparse. The crawled /docs, /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed description of what the holdings response contains. The endpoint is confirmed live (returns a proper 402 challenge), but the lack of documentation means callers must discover the request format and response shape experimentally.
Capabilities
Use cases
- —Retrieving current holdings for a specific portfolio
- —Building portfolio tracking dashboards with per-call payment
- —Integrating portfolio data into autonomous agent workflows without API key management
Fit
Best for
- —Agents or apps that need on-demand portfolio holdings data without subscription commitments
- —Developers experimenting with x402 micropayment-gated APIs
- —Low-volume consumers who prefer pay-per-call over monthly plans
Not for
- —High-frequency trading systems needing sub-second latency guarantees (no SLA documented)
- —Users who need detailed API documentation or schema validation before integration
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/30/holdings \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing, but there is zero documentation on request body format, response schema, or what 'portfolio 30' represents. No OpenAPI spec, no examples, and all doc pages are empty. This is effectively a stub listing.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README all return only a wallet-connect prompt with no content
- —No OpenAPI or request/response schema provided; callers must guess the request format
- —The endpoint is hardcoded to portfolio ID 30 — unclear if other portfolio IDs are available or what this portfolio represents
- —No SLA, rate-limit, or uptime guarantees documented
Citations
- —Endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/30/holdings
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/30/holdings