export NVM_DIR="$HOME/.nvm" && . "$NVM_DIR/nvm.sh" && nvm use --lts && mintlify dev

Mintlify shows the right-hand table of contents and highlights the active section, but the mint theme (and the open-source CLI build) doesn’t include the track bar—the vertical rail with a moving thumb that animates to the current section. That behavior is common on some themes or on Mintlify’s hosted product; it’s not in the default mint theme you get with mintlify dev.

This repo adds it via:

• CSS (styles.css): track rail + thumb styles and active-section left border.
• JS (scripts/toc-track.js): wraps the TOC in a track, adds a thumb, and moves it to the active item with a short animation.

Mintlify (Growth plan) can load custom script files from your repo. After you push, the script should be picked up in production. For local dev, if the track bar doesn’t appear, load it once from the browser console on any doc page:

var s = document.createElement('script'); s.src = '/scripts/toc-track.js'; document.body.appendChild(s);

If that path 404s, the CLI isn’t serving repo files; the moving thumb will still work when deployed to Mintlify. The active-section left border (CSS) works either way.