Chromium Engine

Overview

Veilus profiles run on a standalone, custom-patched Chromium build, launched as its own process — not a copy of Chromium embedded inside Electron. This engine is downloaded and managed separately from the Veilus app itself: a fresh install has no engine until you download one from the Engine Manager, at which point Veilus activates it automatically.

Engine Manager

Open Settings from the sidebar; the Engine section (Chromium Version Manager) shows:

• The version currently in use, if any (for example, 153.0.8010.37)
• Sync from Cloud — fetches the list of available versions from Veilus’s servers, along with their signed checksums. This also runs once, silently, whenever you open the Settings page.
• Total disk space used by the builds you’ve downloaded, and a Cleanup Old button (shown once you have more than one build downloaded) that deletes every downloaded build except the one currently active
• A list of versions available for your platform, each showing:

Badge / info	Meaning
Active	The build new profiles launch with
Latest	The newest build available for your Veilus version and platform
Size, or “Not downloaded”	Whether the build is on disk, and how much space it uses
Released date	When that Chromium build was released

Depending on its state, a version’s row offers Download, Activate, Redownload, and Delete.

Every download is checked against Veilus’s signed version index (SHA-256) before it’s kept. If a build has since dropped out of that signed index, Veilus won’t touch your existing install of it — you’ll see a message telling you to sync again instead.

Updates

Settings → Updates only shows the engine build currently in use (“Engine in use: <version>”). It doesn’t check for new versions or switch builds — that happens in the Engine section above.

There is no scheduled or background check for new engine versions, and no setting to turn one on or off. Veilus syncs the version list once, silently, whenever you open Settings; otherwise, syncing happens only when you click Sync from Cloud yourself.

Getting a newer engine version

1. Settings → Engine → Sync from Cloud
2. Find the version tagged Latest
3. Download it, then Activate it

Profiles you open afterward use the newly activated build. Profiles that are already open keep running on whichever engine they were launched with — activating a different version doesn’t restart them.

Switching between installed versions

Click Activate on any already-downloaded version to make it the one new profiles use. There’s no separate “pin” step: whatever you last activated stays active until you activate something else — Veilus never switches it back on its own, since there’s no automatic update to begin with.

Caution

Older engine builds can fail checks on sites that look at the Chrome version. Keep the active build reasonably current unless you have a specific reason to stay on an older one — for example, matching a fixed version across automation runs.

Why not Electron?

	Veilus engine	Electron-based tools
Runtime	A standalone, genuine Chromium binary, launched as its own process	Chromium and Node.js bundled inside the app’s own process
Automation access	The standard Chrome DevTools Protocol, which Veilus’s automation uses	Varies by app

Troubleshooting

Engine won’t download

• Check your internet connection
• Make sure your firewall allows HTTPS to api.veilus.io (the version list and download links) and to Cloudflare R2 (the engine package itself)
• If the error says a build is no longer in the signed list, click Sync from Cloud and try again

Engine won’t start, or delete/redownload fails

• On Windows, close any profile windows still using that build first — Windows keeps its files locked while a browser built from it is running, which makes delete and redownload fail
• From Settings → Engine, use Delete then Download to reinstall the build (or Redownload if it’s the active one)
• If Veilus itself won’t start, quit it, remove the version’s folder under ~/.veilus/engines/<version>/ by hand, then relaunch and download the engine again

Sites detect an outdated Chrome version

• Settings → Engine → Sync from Cloud, then download and activate the version tagged Latest