Portfolio performance data via x402 micropayment on Base network for $0.02/request
What it does
This endpoint at lowpaymentfee.com provides portfolio performance data behind an x402 paywall. The specific resource `/api/v1/portfolios/9/performance` returns JSON data related to portfolio #9's performance metrics. Payment is settled in USDC on the Base network at $0.02 per request (20,000 base units with 6 decimals).
The endpoint is part of a broader platform (lowpaymentfee.com) that offers a variety of pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3 data, and utility services — all priced at $0.02 per request via the x402 protocol. The platform advertises no API keys, no rate limits, and instant access. Payment is made by including an X-PAYMENT header with a valid x402 payment proof.
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 detailed description of what the portfolio performance response actually contains. The endpoint is confirmed live (returns 402 with a valid x402 challenge), but the actual data payload and input parameters are unknown.
Capabilities
Use cases
- —Retrieving performance metrics for a specific investment portfolio
- —Integrating portfolio performance data into dashboards or agents
- —Programmatic access to portfolio returns without API key management
Fit
Best for
- —Agents or apps needing on-demand portfolio performance data with no subscription
- —Developers wanting frictionless pay-per-call finance APIs on Base
- —x402-compatible clients looking for low-cost financial data endpoints
Not for
- —Users who need detailed API documentation or response schema before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone needing portfolio data for portfolios other than #9 (only this specific resource is confirmed)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/9/performance \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is confirmed live with a valid x402 challenge, but there is no OpenAPI schema, no request/response examples, and all documentation pages returned only a wallet-connect prompt. The actual data returned and accepted input parameters are completely unknown.
Warnings
- —No API documentation available — /docs, /api, /pricing, /README all return only 'Connect wallet' with no content
- —No OpenAPI or schema describing request parameters or response format
- —Only portfolio #9 is referenced in this endpoint; unclear if other portfolio IDs are valid
- —The nature and source of the portfolio performance data is unspecified
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base network at maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/portfolios/9/performance
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/9/performance