Portfolio performance data via x402 micropayment on Base network, $0.02 per request.
What it does
This endpoint at lowpaymentfee.com returns portfolio performance data for a specific portfolio (ID 21) behind an x402 paywall. It accepts POST requests and responds with 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, hosts a broad catalog of x402-gated APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all priced at $0.02 per call. This specific endpoint sits under the finance category and appears to deliver performance metrics for a pre-defined portfolio. No API keys or rate limits are advertised; access is granted instantly upon valid x402 payment.
Documentation is extremely sparse. The docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further 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 without documentation it is difficult to know what request body (if any) is expected or what shape the response takes.
Capabilities
Use cases
- —Retrieving performance metrics for a tracked 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 signup
- —Developers experimenting with x402 micropayment-gated APIs
- —Low-volume, pay-per-call financial data consumers
Not for
- —Users needing detailed API documentation or response schemas before integrating
- —High-volume bulk data retrieval where per-call pricing adds up
- —Anyone requiring historical or customizable portfolio definitions (this is a fixed portfolio ID)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/21/performance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty stubs. The specific purpose of portfolio 21's performance data is unexplained.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet' with no content.
- —No request body schema or response schema provided; callers must guess at the expected input and output format.
- —Portfolio ID 21 is hardcoded in the endpoint path with no explanation of what portfolio it represents.
- —The provider hosts many diverse endpoints (AI, analytics, finance, utilities) all at $0.02 — unclear whether these are production-quality or demonstration/placeholder services.
Citations
- —Endpoint returns 402 with x402 challenge advertising USDC on Base network at maxAmountRequired 20000https://lowpaymentfee.com/api/v1/portfolios/21/performance
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/21/performance
- —All APIs priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com