Portfolio performance data via x402 micropayment on Base network, $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com returns portfolio performance data for portfolio ID 27. It is part of a broader platform offering various pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services. All endpoints on the platform use the x402 payment protocol, settling in USDC on the Base network at $0.02 per request.
The specific endpoint `/api/v1/portfolios/27/performance` accepts POST requests and returns JSON. The x402 challenge confirms it is live, requiring a maximum of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) paid to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base. No API keys or rate limits are advertised; access is gated purely by the x402 payment header.
Documentation 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 description of what fields the portfolio performance response contains. The endpoint path suggests it returns performance metrics (e.g., returns, gains/losses) for a specific portfolio, but the exact schema is unknown.
Capabilities
Use cases
- —Retrieving performance metrics for a specific investment portfolio
- —Integrating portfolio performance data into dashboards or agent workflows
- —Programmatic access to portfolio analytics without API key management
Fit
Best for
- —Agents or apps needing on-demand portfolio performance data with no signup
- —Developers wanting x402-native pay-per-call finance endpoints
- —Crypto-native workflows settling micropayments in USDC on Base
Not for
- —Users needing detailed API documentation or response schema guarantees before integrating
- —Bulk historical portfolio data retrieval (no batch or streaming support documented)
- —Non-crypto payment workflows (only USDC on Base is accepted)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/27/performance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing, but there is no OpenAPI schema, no request/response examples, and all documentation pages are empty stubs. The purpose of the endpoint can only be inferred from the URL path. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — response format is entirely unknown
- —All doc/pricing/README pages return only 'Connect wallet' with no content
- —Portfolio ID 27 is hardcoded in the path; unclear if other portfolio IDs are available or how they are discovered
- —No information on what POST body (if any) is expected
Citations
- —The endpoint returns a 402 x402 challenge requiring 20000 base units of USDC on Base (=$0.02)https://lowpaymentfee.com/api/v1/portfolios/27/performance
- —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: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/27/performance