Do you even need a computer for this?
Short answer: no — a couple of tiny Canaries and a palm-sized screen can watch a room and prove what they saw, all on their own. Longer answer: add a small Linux computer — a $60 Raspberry Pi will do — and you unlock the heavyweight stuff: real cameras, an encrypted memory, and a vault no single person can open. Here's what Linux even is, why a Pi is a great home for it, and exactly what you gain — or happily skip.
Three things to hold onto
Stands alone
The Canaries sign what they see and a palm-sized screen verifies it — no computer in the loop.
Grows with a Pi
Add a cheap Linux computer and it gains cameras, a forensic memory, and a break-glass vault.
You choose
Start tiny, add the brain later — or never. Flip a switch below and see exactly what changes.
First — what even is Linux?
Linux is an operating system: the free, open layer of software that sits between raw electronics and the programs you actually use. It quietly runs most of the serious computers on Earth — the web's servers, Android phones, and yes, the little Raspberry Pi. Tap a layer to see what it does.
In plain terms: think of a computer as three layers, like an onion. At the core is the hardware (the chips). Wrapped around it is the operating system — Linux — which knows how to talk to cameras, disks, and the network so no single app has to. On the outside are the apps, like our witness kernel. Linux is the reliable middle layer that makes the hard parts possible.
The three layers of a computer
tap a layer—
Quick untangling of a confusing word: Linux has a “kernel” (the very core of the operating system), and we have a “witness kernel” (our privacy engine). Same word, two different things — ours is an app that runs on top of Linux, not a replacement for it.
Why it matters here: the heavy, careful work — talking to real cameras, keeping an encrypted database, locking programs in a safety sandbox — is exactly the kind of thing a real operating system is built to do. That's the whole reason the powerful tier needs Linux, and the tiny screen doesn't try to.
The dashboard can fit on a screen the size of your palm.
The Canary Dash is a little touchscreen — a Waveshare ESP32-S3 board with a 4.3-inch display. It has no operating system and no hard drive, and it doesn't need them. Its whole job is to listen to your Canaries, check their signatures on its own chip, and show you the truth.
- Verifies every signature on its own silicon — the “verified ✓” on the glass means the same math the Home Assistant integration runs.
- Shows the whole fleet — who's live, who's gone quiet, who reported tamper — with a timeline you can hold-to-acknowledge.
- Finds and cross-checks other Canaries over your local network, and shows a join-QR on its own screen for new ones.
- Keeps working if the network drops — it falls back to short Bluetooth “chirps” so liveness and tamper still reach the glass.
Straight with you: the Dash is in development — the firmware is compile- and CI-tested but not yet validated on bench hardware, and it's a viewer, not a sensor (the sensing Canaries are the ones that mint signed claims). We'll never mark it “shipping” before it is.
Add a $60 computer and it grows a memory, cameras, and a vault.
A Raspberry Pi is a full computer the size of a deck of cards. Run our witness kernel on one (it installs as a Home Assistant add-on — no scary command line), and the little presence network becomes a full forensic system. A Pi 4 with 4 GB is plenty; a Pi 5 or any spare PC works too.
Why a Pi is such a good fit: it's cheap, sips power (you leave it on 24/7 for pennies), and runs Linux — so it can do the heavy lifting a microcontroller can't: watch real cameras, keep an encrypted database, and run programs in a locked-down safety sandbox. It's the natural “always-on” home for the witness kernel.
And you can absolutely skip it. If all you want is honest presence — “someone's at the door,” signed and verifiable — the Canaries and the Dash do that with no Pi in sight. The Pi is for when you want to add real cameras and courtroom-grade evidence. Start without one; add it the day you want more.
Two honest footnotes: it needs a 64-bit Pi (Pi 4 or 5) or an x86 PC running Home Assistant OS — not an ancient 32-bit board. And even the “no-Pi” setup wants a little always-on message broker somewhere on your network; a Pi is just the usual, tidy home for it.
Flip the switch: exactly what you unlock with a Pi.
Same eight jobs, two setups. Toggle between just the Canaries and adding a Raspberry Pi and watch what lights up. Nothing here is aspirational — it's what the code does today (with the honest notes from above).
- Sense presence & motion, and sign the claim right on the sensing Canary's chip.
- Verify every signature and show the fleet — on the palm-sized screen itself.
- Discover and cross-check other Canaries over your local network.
- Keep going if the network drops — Bluetooth “chirp” fallback for liveness & tamper.
- Witness real IP / RTSP cameras through Frigate — the best-supported camera path.
- Keep an encrypted, tamper-evident forensic log (an on-disk SQLCipher database).
- Seal video evidence in a vault — opened only by an N-of-M “break-glass” quorum.
- Run sandboxed modules, retention, digests and full Home-Assistant dashboards.
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So — do you need a Pi?
Pick what you're actually after. There's no wrong answer, and you can change your mind later — the tiers grow into each other.
The Canaries on their own
A couple of sensing Canaries and a Dash screen cover this beautifully — signed presence, verified on the glass, no computer to babysit. (Keep a small always-on broker on the network; a spare Pi is a fine home for it, but so is an old mini-PC.)
Start tiny. Grow when you want. Never forced onto a computer.
The Canaries prove what they see whether or not a Pi is watching. Add one the day you want cameras and a vault — and if that day never comes, nothing about the little network is missing the point.