If you self-custody Bitcoin, there’s a simple but uncomfortable question:

If my cold storage ever moves, how do I know immediately, without trusting anyone with my keys or wallet data?

I built Canary to answer that.

What it is

Canary is a Bitcoin monitoring tool for cold storage.

It watches watch-only data only (based on output descriptors or xpubs) and alerts you if:

• funds move
• balances change
• something unexpected happens

It never signs.
It never spends.
It never touches private keys.

Self-hosted first (the default mindset)

The core use-case is self-hosting:

• Runs next to your own Bitcoin node
• No xpub sharing
• No third-party indexers
• No cloud dependency
• Nothing valuable to steal even if compromised

Supported out of the box on:

• Umbrel
• Start9

and any Docker setup, source available on GitHub.

Notifications via ntfy (also self-hostable)

Alerts are sent using ntfy:
• Simple push notifications
• Works on mobile and desktop
• Can be used via public ntfy servers or
• Fully self-hosted, just like Canary itself

End result: monitoring + notifications can be 100% under your control.