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 29. It is part of a broader platform offering pay-per-request APIs across data analytics, AI/ML, finance, and infrastructure categories, all settled via the x402 protocol on the Base network using USDC.
The endpoint accepts POST requests and returns JSON. Payment is handled inline via the X-PAYMENT header using the x402 exact scheme. The maximum amount required per call is 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals). The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 on Base. No API keys or rate limits are advertised; access is gated solely by micropayment.
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 is confirmed live (402 challenge captured), but the actual data returned after payment is unknown.
Capabilities
Use cases
- —Retrieving performance metrics for a specific investment portfolio
- —Programmatic portfolio monitoring by AI agents paying per request
- —Integrating portfolio data into dashboards without API key management
Fit
Best for
- —Agents or apps that need on-demand portfolio performance data without subscription commitments
- —Developers wanting to test x402 micropayment integration on Base
- —Use cases requiring keyless, pay-as-you-go API access
Not for
- —Users needing detailed API documentation or response schema before committing
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone needing portfolio data for IDs other than 29 (no evidence other IDs are supported at this endpoint)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/29/performance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"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 schema, no request/response examples, and all documentation pages are empty stubs. The purpose of the data (portfolio 29 performance) is only inferable from the URL path.
Warnings
- —No documentation available — docs, API, pricing, and README pages all return only a wallet-connect prompt with no content.
- —No request or response schema provided; the structure of the returned portfolio performance data is unknown.
- —The endpoint is specific to portfolio ID 29; it is unclear whether other portfolio IDs are supported or what they represent.
- —No OpenAPI spec or ai-plugin manifest found.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/29/performance
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/29/performance