When developing and testing the web interface, it's handy not to bother with re-flashing an ESP32 each time. The idea is to mimic the ESP using a mock/stub server that responds to the REST (HTTP POST & GET) and WebSocket calls.

prerequisites

Install the latest LTS of NodeJS
install corepack npm install -g corepack@latest and orepack enable
Install pnpm (corepack use pnpm@latest-10 on linux or winget install -e --id pnpm.pnpm on windows). See https://pnpm.io/installation
Install bun (https://bun.sh/docs/installation)
type pnpm install from this mock-api folder to build

To run

pnpm standalone from the main interface folder and then navigate to http://localhost:3000