// Overlays

Themes you can drop in.

Live preview each overlay below, then download the .nerva-overlay bundle and import it from the desktop app. Every theme is open HTML/CSS/JS, yours to remix.

  • Default

    Bundled

    Clean, minimal, dark. The Nerva reference theme. Live BPM, status, optional stress meter.

    Ships with the desktop app, no separate download.

  • Cortisol meter

    Classic infographic-style cortisol gauge: 6-segment half-dial with a swinging black needle driven by stress, BPM readout below.

    Download Cortisol meter

  • Cortisol meter (clear)

    Cortisol meter without the white card. Dial and BPM readout straight on transparent, to drop over gameplay without a visible frame.

    Download Cortisol meter (clear)

  • Tunnel vision

    Full-screen stress effect: peripheral darkening, backdrop blur, and radial speed lines breathing at heart-rate tempo. Invisible at rest, intense above 70.

    Download Tunnel vision

More themes coming. A public marketplace is on the table, no date yet.

Want one nobody else can run?

Skin, Brand, Signature. Three tiers, quote-based, weekday turnaround.

Commission a custom theme

// FAQ

Overlay questions.

Are the Nerva overlays free?

Yes. Every theme on this page is free to download and use with the Nerva desktop app, during the one-month trial and on any paid plan. You can also remix one or commission a custom theme.

Do Nerva overlays work in OBS?

Yes. Each overlay is a local browser source: import the .nerva-overlay bundle into the desktop app, then add the overlay as a Browser source in OBS or Streamlabs. It behaves the same on Twitch, YouTube, and Kick.

Can I edit a Nerva overlay myself?

Completely. Overlays are open HTML/CSS/JS folders that read live CSS variables (BPM, stress, zone), so you can restyle a bundled theme or build your own from scratch and package it as a .nerva-overlay. The overlay dev guide walks through the API and packaging.

What do I need to use an overlay?

The Nerva desktop app (Windows, macOS, or Linux) and a BLE heart-rate sensor like a chest strap or compatible watch. No phone, no cloud account. Pair the sensor, import the overlay, drop it into OBS.

Building your own? See the overlay dev guide.