Why Osaurus: private, local AI that runs on your Mac

What does Osaurus actually do?

Built entirely in Swift, Osaurus transforms your Mac into a versatile, private personal computer by running local LLMs directly on your own hardware. Because everything operates locally, there are no remote servers processing your data, no accounts to manage, no usage caps, and no hidden bills. It is model-agnostic allowing you to change at will. By completely removing the friction and privacy concerns of cloud-based AI if desired. Osaurus provides a seamless, uncapped environment where the only thing limiting what you can build is your imagination.

Which Mac apps does Osaurus work with?

Osaurus connects to the apps you already use.

App integrations

• Mail: Read, search, compose and manage Apple Mail, locally and privately.
• Calendar: See your events, search them, create them.
• Messages: Read and send iMessages.
• Reminders: Read, search, create and manage your lists.
• Music: Control playback and search your library.
• Vision: Read text out of images and screenshots, on your own machine.
• Files: Read, write and organise your files and folders - plus Git, if you work in code.
• Voice: Dictate into any app with a global hotkey. Transcription runs on Apple's Neural Engine, so no audio leaves your Mac. It reads back to you too.
• Shortcuts, Spotlight and Siri: Trigger Osaurus the way you already trigger everything else on your Mac.
• Notes - list, search and create Apple Notes
• Contacts - find contacts by name or phone, pull numbers
• Maps - search locations, get directions, manage guides

Files and web

Plus your documents: Excel workbooks, PowerPoint decks, PDFs, images, whole folders. Web search and a browser are built into the app, for the jobs that need the internet.

Driving other Mac apps

Osaurus can also work an app directly - Finder, Safari, System Settings, Notes, anything with a window - reading the screen through the macOS accessibility tree rather than pixels, and delegating to AppleScript for the apps that script better than they click.

This one is deliberately on a short lead. It is off by default, switched on per agent, and still experimental. Out of the box it asks you before anything that edits or commits, and sensitive apps like Terminal, System Settings and password managers always require a confirmation no matter how you have it set. You can restrict it to an allowlist of specific apps, and cap how much freedom any single agent gets.

What it sees stays local by default too: the accessibility tree, any screenshots and the OCR all run on your Mac. A screenshot only reaches a cloud model if you turn that on yourself, and even then every piece of readable text is masked out first.

Code execution sandbox (macOS 26+)

On macOS 26 and later, agents can also run code in an isolated Linux VM built on Apple's own Containerization framework - a real dev setup with no risk to your Mac.

End-to-end task automation

Instead of you being the middle step - copying something out of Mail, pasting it into a chat window, copying the answer back - Osaurus does the job for you:

• Find the email, pull the dates out, put them in your calendar, message the person to confirm.
• Read a stack of documents and build the spreadsheet for your work project.
• Tidy a large, messy folder full of random downloads.
• Draft a party invitation flyer.
• Create a tailored diet plan.

The effect is that it stops feeling like an AI you talk to and starts feeling like a computer that gets on with your work. With a persistent memory. Your own computer, doing your own work, with your own files, in your own apps - and none of it leaving the Mac. All on your own rules.

Does Osaurus work with the tools I already use?

OpenAI, Anthropic and Ollama-compatible endpoints

Anything built for OpenAI, Anthropic or Ollama can point at Osaurus. Same endpoints, running on your Mac at localhost. If you built something, or you use a tool that expects one of those, it works - with a local private model behind it and no bill.

Apple Foundation Models (macOS 26+)

Apple's own model is built in. On macOS 26 or later, Apple Foundation Models work as a first-class provider alongside everything else. On-device, zero inference cost, fully private.

Claude plugins

Claude plugins run in Osaurus. Import a full Claude plugin from any GitHub repo: skills, scheduled agents, slash commands, MCP providers, CLAUDE.md context. Agent Skills work too. Bring them to the machine you own.

Communication tools

Slack, Discord, Telegram , iMessage and WhatsApp are available for configuration for use on the move.

MCP, both directions

The same goes in both directions for MCP, the standard everything is settling on. Osaurus is a full MCP server, so any MCP-compatible client can use your local tools. And it is an MCP client, with one-click links to around 25 services like Linear, Notion, GitHub, Stripe, Supabase, Sentry, Vercel, Cloudflare and more.

The point of all of this: you are not stepping outside the ecosystem to get privacy. You are bringing the ecosystem home.

Can one AI remember everything?

One memory across many models

You probably use more than one. ChatGPT for some things, Claude for others, Gemini because it is already in your email. Grok for research. Each is a separate tab, a separate plan and - the genuinely annoying part - a separate memory. Every one of them starts from zero, every time.

Osaurus puts them together. Open models run in the app, on your chip. When a job wants a frontier model, connect ChatGPT, Claude, Gemini, Grok, OpenRouter or Venice - which is built for privacy and keeps nothing - and use it for that task. One memory runs across all of them, and it lives on your Mac. Yours forever.

Bring your history

You can bring your history over too - the chats from your existing AIs - so you keep everything you have already built up.

Local models that are not a compromise

Because Osaurus builds its own open models, tuned on Apple Silicon for steady tool use, the local option is not a compromise you settle for with an Apple native design.

The practical effect: your AI finally knows you, in a place you control. The models will keep changing. The harness - your memory, your tools, your continuity - stays yours.

How is Osaurus private by default?

When the model runs on your Mac, your work simply does not go anywhere. There is no upload. No account. No server logs, because there is no server. Nothing sitting on someone else's system under terms that can change.

You can prove it in seconds: disconnect from the internet and keep working.

You decide what leaves. Every time.

• Fully offline with a local model. Not a limited mode. The normal way it works.
• Cloud when you actually want it. One click for a specific task, then back. You are not stuck with local models only, and you are not quietly sending everything away either.
• And your agents are yours, provably. Every agent, device and person gets a cryptographic address, with authority flowing from your master key in the iCloud Keychain. You can grant an agent access, limit what it can reach, and revoke it whenever you like.

Optional redaction gate for cloud requests

Osaurus includes an optional redaction gate for cloud requests. Switch it on and it finds sensitive content on the way out, shows you exactly what it found, swaps it for placeholders, sends the scrubbed version, and puts the originals back locally when the reply comes in.

What it catches. Out of the box it catches set patterns - emails, URLs, credit card numbers, and US-style phone numbers and Social Security numbers - with opt-in presets for IBANs, AWS and GitHub keys, and US passports and driving licences. Several of the built-in patterns are US-shaped, so if you work with numbers in another format, add them yourself: the rule builder takes plain terms and writes the pattern for you, no regular expressions needed. Turn on the optional on-device checker and it also catches names, addresses, dates and free-form secrets. That checker runs entirely on your Mac: no third-party model ever sees your text, not even to decide what counts as sensitive.

Fail-closed behaviour. The important part is what happens when it is unsure. The gate is fail-closed. If the post-scrub check still finds something, the send is blocked and you are told why. It never quietly falls back to sending the original. And you can check it yourself - open Insights and read the exact bytes that went to the provider.

Caveats. It is off by default and still experimental, so turn it on deliberately and keep the review sheet on for anything that matters. It does not read images or audio, and it will not redact a topic - only the things in the text.

What data does Osaurus collect?

Your chats, prompts, files, docs and model output never leave your Mac. Not to us, not to anyone. There is no account and no permanent ID, so nothing is tied to you.

Anonymous usage analytics

Anonymous usage analytics are on by default, and you can turn them off. Before anything is sent, the first onboarding step shows you a tick box explaining exactly what is collected - the handful of events from launch until that moment are held in memory, never written to disk, and dropped if you untick it. You can switch it off any time in Settings → Privacy, and sending stops at once.

Crash and hang reports

Crash and hang reports work the same way - separate switch, same place. They exist so we can fix real bugs.

What is never included

Neither ever includes your chats, prompts, model output, tool arguments, file contents or paths, API keys, agent names or chat titles. Both are off entirely in builds made from source. Every analytics event is documented in public, and you can read the code.

Who is Osaurus for?

For anyone with a Mac

If you have a Mac, it is for you.

Osaurus is a powerful AI app before it is a private one. People use it to write and rewrite, to get on top of a mountain of documents, to plan things, to code, to learn, to tidy up files they have been avoiding, to draft the hard email, to make sense of a complex spreadsheet. Students and teachers. Writers. Freelancers and small business owners. Developers. People running a home. People who just want a capable assistant that is not asking them to subscribe to anything.

And nearly everyone has some things they would rather keep to themselves. The new job application. The half-finished novel. The family medical admin. Your accounts. Not because any of it is scandalous, but simply because it is yours. That is most people, and that is the point.

For confidential work

For some people privacy is not a preference at all. It is the job.

Solicitors and lawyers. Therapists and counsellors. Doctors, nurses and clinicians. Teachers and school staff, who hold pupil records and safeguarding notes. Accountants and bookkeepers. Journalists protecting a source. HR teams handling grievances, investigations and salary data. Social workers. Financial advisers. Vets, architects, carers, coaches, translators, recruiters, charity workers, civil servants, clergy, researchers under ethics approval, and anyone working under an NDA.

If someone told you something in confidence, a cloud AI tool leaves you in an awkward spot. Not because you have done anything wrong, but because you cannot fully answer where it went, who can see it, or what happens to it next.

Running the model on your own machine removes the question. Nothing was disclosed, because nothing left. Keep the work local and it stays local - and if you ever do reach for a cloud model, that is a decision you make for that one task, with a redaction gate you can put in front of it.

Will Osaurus run on my Mac?

Hardware and OS

You need an Apple Silicon Mac (M1 or later) running macOS 15.5 or later. That is it for the app itself.

Performance on typical Macs

You do not need a top-end machine. Osaurus suggests a model sized for the Mac you actually have and installs it for you, so an ordinary 16GB MacBook has a sensible local model running within minutes of opening the app. Want something bigger? Choose a larger model. Want to check first? Our Discord will tell you what runs well on your exact machine.

Features requiring macOS 26

Two features need macOS 26 (Tahoe) or later: the isolated Linux sandbox for running code, and Apple Foundation Models. Everything else on this page works on macOS 15.5 where a Seatbelt fallback is operational.

Why Mac-only (for now)

Being Mac-only is a deliberate choice for now. Building native to one platform is why it is fast, why it can drive your other apps properly, and why running a real local model on a laptop is practical today.

What does Osaurus replace?

This one creeps up on people the more they use their agents. Most of us have assembled a pile of software: something to chat with, something to hold documents where an AI can read them, something so your AI remembers you between tools, something to strip private details before you paste anything, a browser assistant, a dictation app - and a subscription to each AI provider on top.

Osaurus does all of those jobs in one place.

What you would otherwise pay for

• A completely free AI optimized for your Mac - no tokens nor top-up required, ever
• A second brain for your documents
• One memory that follows you across local models, ChatGPT, Claude, Gemini and Grok should you require them
• A tool to redact sensitive text before you send it
• Local image generation
• A browser assistant
• Dictation and read-aloud
• Voice transcription
• Automation, scheduling and folder watchers
• Computer use
• Real Mac control
• A private, offline model interface
• An isolated sandbox to safely execute commands
• A fully offline and private productivity suite

Osaurus runs on your own machine. The app is free and open source under the MIT license. There is a straight answer as to why we can give it away.

Can you actually trust it?

Fair question, and the honest answer is: do not take our word for it, check.

• Read the code. The whole thing is public and MIT licensed - more than 7,600 GitHub stars, over 2,500 commits, nearly 450 forks and a public issue tracker.
• Read the docs. Every telemetry event, every privacy setting and every limitation is written down.
• Read what other people say. More than 200,000 downloads so far. Osaurus has been covered by TechCrunch, came second on Product Hunt's Product of the Day, and is backed by Alliance. The press coverage is collected on our media page.
• Turn the Wi-Fi off. Still the best test there is.

Common questions

You will not be left to work it out alone

Guided setup and built-in help

Setup walks you through choosing a model. There are built-in guides for the things people get stuck on, skills you can switch on instead of build from scratch, and themes if you want it to look like yours. Your friendly dino will help.

Community and support

And you can ask a real person. Our Discord is a room with the people who build Osaurus and the people who use it, so come with questions and get them answered. There is a subreddit too.