I'm building a proactive personal assistant for the Mac called recal. It watches how I work, learns my patterns, and starts doing the repetitive busywork for me. The one constraint I refused to bend on: it runs entirely on-device. No cloud, no account, no server. 0 bytes of my activity leave the machine.
This is the honest engineering version of that decision: why I made it, what it bought me, and what it genuinely cost. I'm the founder, building in public, and the product is pre-launch, so this is about the architecture, not a sales pitch.
Privacy by architecture, not by policy
Every AI productivity tool I tried wanted the same thing: my screen, my files, my activity history, living on someone else's server. For a tool whose entire job is to watch how I work all day, "trust our privacy policy" was never going to be enough. A policy is a promise. Architecture is a guarantee.
If the data never leaves the device, there is no server to breach, no account to leak, no policy to quietly change next quarter. You can pull the ethernet cable and it still works. That is a fundamentally different security model than "we encrypt it in transit."
