Installation

Osaurus is a free Mac app. To install it, download it, drag it into your Applications folder, and open it. You need a Mac with an M-series chip (Apple Silicon) running macOS 15.5 or later.

Download from osaurus.ai    Latest release on GitHub

Get started

1. Download Osaurus from osaurus.ai (or from GitHub Releases). The file ends in .dmg.
2. Open the downloaded file and drag Osaurus into your Applications folder.
3. Eject the downloaded disk (click the eject icon next to it in Finder), then open Osaurus. A quick way: press ⌘ Space, type "Osaurus", and press Return.

Apple has checked and approved Osaurus (it's signed and "notarized"), so it opens without security warnings. The app updates itself when you open it, so you don't need to come back here for new versions.

Next: Quick Start → walks you through first launch.

System requirements

• macOS 15.5 or later
• Apple Silicon (M1, M2, M3, or newer)
• 2–20 GB of free space for each local model you download

macOS 26 features

Apple Intelligence models need macOS 26 (Tahoe) or later. The Sandbox (a sealed-off area where agents can run code) works on both macOS 15 and 26, with a fuller setup on macOS 26.

Pick a build

Each release comes in two downloads. They're the same app; the difference is whether an AI model comes included.

Download	Size	Who it's for
Standard	~80 MB	Most people. During setup you download a model or start on Osaurus Cloud.
Full	~3.6 GB	People who want to chat offline right away. It includes the Raptor 0.6 model, so setup skips the download.

The full download is linked from each release's notes and is also hosted on Hugging Face. After a full install, future updates are the small standard download.

Permissions

Osaurus only asks for a permission when you first use a feature that needs it. macOS shows the request, and you can change your answer later in System Settings → Privacy & Security.

Permission	What it's for
Microphone	Talking to Osaurus, starting a chat with a wake word, and Transcription Mode
Screen Recording	Capturing your Mac's sound for transcription
Accessibility	Transcription Mode (typing into other apps for you)
Network	Cloud models, online tools, and Public Links
Files	Working Folders (one folder at a time, and only the ones you pick)

Troubleshooting

"Cannot be opened" error

This shouldn't normally happen, because releases are checked by Apple. If you see it, the download was probably damaged or came from an unofficial site. Delete the app, download it again from osaurus.ai or GitHub Releases, and reinstall. As a last resort, open System Settings → Privacy & Security, scroll to the message about Osaurus, and click Open Anyway.

osaurus command not found

This only matters if you use the Terminal. See Install the command-line tool below.

Some data won't open after upgrading or moving to a new Mac

Osaurus never deletes your data when it can't open it. Go to Settings… → General → Advanced → Data & Storage → Stores Needing Attention, where each affected item has Retry and Reset buttons. Anything you reset is moved aside, not deleted. Full guide →

Uninstall

1. Quit Osaurus.
2. Drag Osaurus from your Applications folder to the Trash.
3. (Optional) To remove your chats, memory, and downloaded models too, see Remove everything below.

warning

Removing your data can't be undone. To keep a copy of your chats and memory first, use Settings… → General → Advanced → Data & Storage → Export plaintext backup….

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Under the hood

Build files

Build	File name	Notes
Standard	Osaurus-<version>.dmg	Homebrew and in-app updates use this build.
Full	Osaurus-<version>-full.dmg	First launch installs the bundled Raptor 0.6 into ~/MLXModels, and onboarding skips the AI setup step.

Osaurus is Developer ID signed and notarized by Apple. Updates install automatically through Sparkle when you launch the app. File access for Working Folders uses macOS security-scoped bookmarks.

Install with Homebrew

If you'd rather use Homebrew:

brew install --cask osaurus

This installs the standard build, puts Osaurus.app in your Applications folder, and lets Homebrew manage the osaurus CLI link in its own prefix. Update with brew upgrade --cask osaurus; don't replace that managed link manually.

Where Osaurus puts things

What	Path
Local models (MLX)	~/MLXModels/ (override with OSU_MODELS_DIR)
App data	~/.osaurus/
Voice models	~/Library/Application Support/FluidAudio/Models/
Encrypted databases	~/.osaurus/{chat-history,memory,methods,tool-index}/*.sqlite
Encryption key	macOS Keychain (com.osaurus.storage)
Quarantined (reset) stores	~/.osaurus/quarantine/

To put models on an external drive:

export OSU_MODELS_DIR=/Volumes/External/MLXModels

Verify the CLI

If you installed from the DMG, the easiest way to get the osaurus command-line tool on your PATH is Settings… (⌘ ,) → Server → Overview → Command Line Tool → Install CLI. Then check it from the terminal:

osaurus --version
osaurus serve         # starts the local server
osaurus status        # confirms it's up
osaurus stop          # stops it

If osaurus still isn't on your PATH, link it manually without writing into Homebrew's managed prefix:

cli="/Applications/Osaurus.app/Contents/Helpers/osaurus"
[ -x "$cli" ] || cli="/Applications/Osaurus.app/Contents/MacOS/osaurus"

bin="/usr/local/bin"
if [ ! -d "$bin" ] || [ ! -w "$bin" ]; then
  bin="$HOME/.local/bin"
  mkdir -p "$bin"
fi
ln -sf "$cli" "$bin/osaurus"

If the link lands in ~/.local/bin, add that directory to your shell:

echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc

From a source checkout, scripts/release/install_cli_symlink.sh follows the same /usr/local/bin then ~/.local/bin order. Pass --prefix <directory> only when you explicitly want <directory>/bin.

Test that the local server is up:

curl http://127.0.0.1:1337/health

Remove everything

# If you installed via Homebrew
brew uninstall --cask osaurus

# If you installed manually
rm -rf /Applications/Osaurus.app
rm /usr/local/bin/osaurus 2>/dev/null
rm ~/.local/bin/osaurus 2>/dev/null

# Optional: remove all your data
rm -rf ~/MLXModels
rm -rf ~/.osaurus

# Optional: remove the storage encryption key from Keychain
# (only present if you opted in to storage encryption)
security delete-generic-password -s com.osaurus.storage -a data-encryption-key

Removing ~/.osaurus is irreversible. Export a plaintext backup first if you want to keep your chats and memory.