You manage the context that runs the room. Cossi organises it, surfaces what's drifting, and drafts the outreach — without sending your principal's data to any cloud.
Free to start. Pro features from $9.99/mo.
You brief your principal every morning. You track 50+ stakeholder relationships. You know which decisions are stalled, which relationships are cooling, and which commitments are about to expire. You hold all of it in your head — or in a cloud tool that would alarm any security officer if they knew what was in it.
Cossi is built for the job you already do. It runs on your phone, with no cloud dependency, and no data leaving your device.
Not a general AI. Not a task manager. A private intelligence layer for the specific, high-stakes job of being a Chief of Staff.
The people running the room can't afford to put their principal's context in someone else's cloud. Cossi is the first tool that understands that.
— Built for Chiefs of Staff who operate at the senior-most levels
Cossi was built for the people who handle the most sensitive professional data in any organisation. Your principal's calendar, their stakeholder relationships, their open decisions — none of it is transmitted to any server. The AI model runs on-device. The vault is AES-256-GCM encrypted, keyed from a 24-word seed phrase only you hold. Post-quantum authentication means your session is secure against future cryptographic threats.
Download Cossi, connect your calendar, and your first morning brief runs tonight. Free. No subscription required to start. No data leaves your phone.
