Cadet vs Vellum

Last updated: October 9, 2026

Overview

Cadet is the self-hostable personal AI assistant — run it on your own hardware or in our cloud, with one shared memory across every surface. Vellum is the voice-first assistant you're moving from. This page is focused solely on the migration: your assistant's identity, memory, conversations, skills, schedules, and active work can come with you — nothing has to be rebuilt by hand. Pick the section that matches how you run Vellum today.

Migrating from Vellum

Every path below moves the same data — conversations, memories, skills, schedules, and your assistant's identity — and none of them touch the original: your Vellum install stays exactly as it was until you decide to retire it. Pick the one that matches how you run Vellum today.

1. Vellum Platform users

You run Vellum in the cloud and never want to see a terminal. The whole move happens in the browser:

1. Start the Migrate to Cadet flow here. Vellum issues your migration token and drops you into the Cadet flow.
2. Sign in to (or create) your Cadet account — your Vellum plan carries over as a credit toward the recommended Cadet plan.
3. Review the inventory of what will transfer, approve, and wait for the import to finish.

When it completes, your Cadet assistant picks up where Vellum left off. No downloads, no commands — the cloud does the moving.

2. Non-technical desktop self-hosted users

You run Vellum on your own desktop or mini PC. No terminal, no commands — there's a migration app that does the whole move:

1. Download the migration app from mycadet.ai/downloads?client=migrate-vellum and install it like any other app.
2. Open it and follow the prompts — it finds your Vellum assistant on its own.
3. Review the summary it shows at the end.

The app makes a full backup of your assistant before it copies anything, and it never modifies or deletes your Vellum install — so there is nothing you can break by running it.

3. Technical self-hosted users

Same one-liner, with full control over the flags. Dry-run first if you want to see the plan without touching anything:

curl -fsSL https://mycadet.ai/migrate-vellum.sh | bash

# or, if you already have Node.js 18+:
npx migrate-vellum-assistant-to-cadet --json   # machine-readable report

What the migrator does, in order:

• Discovers your Vellum root from the legacy env overrides (VELLUM_DATA_DIR, VELLUM_WORKSPACE_DIR) or the default ~/.vellum — a candidate only counts if it carries a marker only the assistant creates. Multiple candidates? It asks which one.
• Stops any running Vellum processes before copying. If one refuses to die, the run fails loudly with exit code 4 instead of migrating half-open data.
• Backs everything up first — a timestamped full copy with a sha256 manifest lands in ~/.cadet-migration-backups/<timestamp>.
• Copies read-only — the Vellum root is never written to or deleted. A .cadet-migration-manifest.json in the Cadet root records what happened and makes re-runs verify-only, so it is safe to run twice.

After a successful run, install and launch Cadet on the same machine (the local hosting guide covers setup). Then, once you've confirmed your data is there, retire Vellum for good:

npx migrate-vellum-assistant-to-cadet uninstall

Uninstall is deliberate about it: it asks the Vellum CLI to put any running assistants to sleep, sweeps every Vellum location on the machine (including the XDG config and data dirs and the old home-level lockfiles), and removes the migrator itself. It makes you type DELETE first, because this is the one step that cannot be undone — the Vellum data is gone for good. Your Cadet assistant is safe: nothing Cadet-related is touched, and the migration backups are kept as a last-resort net.