Edge Impulse training pipeline for XIAO ESP32S3 (REST API, verified)

Everything below was executed and verified end-to-end (2026-07). The edge-impulse-cli is NOT needed — do not try to install it (its serialport@8 dependency needs VS C++ build tools on Node 22+).

Step 0 — API key (ask the user)

Ask the user for an Edge Impulse admin API key (ei_...), or read it from the project's .env (EI_API_KEY=...) if the user points you there.