Portfolio performance data via x402 micropayment on Base network, $0.02 per request.
What it does
This endpoint at lowpaymentfee.com provides portfolio performance data for a specific portfolio (ID 99) behind an x402 paywall. It accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) at a cost of $0.02 per request (20,000 base units with 6 decimals).
The provider, lowpaymentfee.com, operates a broad catalog of x402-gated API endpoints spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities — all priced uniformly at $0.02 per call. The specific endpoint probed here (`/api/v1/portfolios/99/performance`) is not listed on the provider's landing page among the advertised APIs, suggesting it may be an unlisted or example route. No OpenAPI schema, request/response examples, or detailed documentation were found during crawling; the docs, pricing, and API pages all returned only a "Connect wallet" prompt with no substantive content.
Because no input or output schema is documented beyond the x402 challenge metadata, callers should expect a JSON response but cannot know the exact shape without experimentation. The endpoint is confirmed live (402 challenge returned successfully). The x402 challenge specifies a 300-second payment timeout and uses the "exact" payment scheme on Base mainnet.
Capabilities
Use cases
- —Retrieve performance metrics for a specific investment portfolio
- —Integrate portfolio analytics into an automated trading or reporting agent
- —Pay-per-call access to financial performance data without API keys
Fit
Best for
- —Agents needing on-demand portfolio performance data without subscription commitments
- —Developers experimenting with x402 micropayment-gated finance APIs
- —Automated workflows that need keyless, pay-per-request financial data
Not for
- —Users who need detailed API documentation or guaranteed schema stability
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone needing portfolio data for IDs other than 99 (no evidence other IDs are supported)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/99/performance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI schema, no request/response examples, and no meaningful documentation. The specific portfolio endpoint is not listed among the provider's advertised APIs. Effectively a stub listing.
Warnings
- —No OpenAPI or JSON schema available for request or response bodies
- —This specific endpoint (/api/v1/portfolios/99/performance) is not listed on the provider's landing page — may be an example or unlisted route
- —All documentation pages (docs, pricing, API, README) returned only a 'Connect wallet' prompt with no content
- —No evidence that other portfolio IDs are supported
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 in USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/99/performance
- —The provider advertises uniform $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/99/performance