# Stop the signal service sudo systemctl stop signal-server echo "SIGNAL_PLUGIN_LICENSE=YOUR_KEY_HERE" >> /etc/signal-server/env Restart and verify sudo systemctl start signal-server signal-admin plugins --verify
| Without Key | With Valid Key | | :--- | :--- | | 5 concurrent users max | Unlimited users | | Logging disabled | Full audit trails | | 30-day trial period | Perpetual or subscription term | | Watermarked UI | Clean branding |
If you’ve been digging into the documentation for Signal’s private server components or enterprise messaging solutions recently, you’ve probably stumbled across the term
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And if you’re like most engineers, your first question was: Wait, Signal is open source. Why is there a license key?
By The Dev Team | 4 min read