Osaurus
by osaurus-ai
Osaurus is a native, offline-first macOS runtime for local and cloud models that runs its own MCP server with 20+ plugins and can also aggregate tools from remote MCP providers.
About
Osaurus is a Swift-native, always-on runtime for Apple Silicon Macs that keeps models, memory, and tool access local: it runs local models directly and can route to cloud providers, exposing everything through more than 20 built-in plugins, including Mail, Calendar, Filesystem, Git, Vision, and XLSX/PPTX handling.
The app is a full MCP server in its own right, bridged to any client with `osaurus mcp` over stdio, and it also acts as an MCP client, aggregating tools from roughly two dozen well-known remote providers, including Linear, Notion, GitHub, Vercel, Supabase, Sentry, Stripe, and Cloudflare, with automatic OAuth so an agent gets one unified toolset instead of juggling separate connections.
Key features
- 20+ native macOS plugins: Mail, Calendar, Filesystem, Git, Vision, XLSX, PPTX, Music, and more
- Runs local models on Apple Silicon or routes to cloud providers, fully offline-capable
- Functions as both an MCP server (osaurus mcp bridge) and an MCP client aggregating remote providers
- Automatic OAuth and Dynamic Client Registration for ~25 well-known remote MCP providers
- Persistent memory and autonomous execution built into the harness itself
- Simple menu-bar app plus CLI (osaurus ui / serve / status)
Use cases
- Running a fully offline, local-first AI assistant on a Mac with persistent memory across sessions
- Giving one agent both native macOS capabilities (Mail, Calendar, Filesystem) and remote SaaS tools (GitHub, Linear, Stripe) without separate setups
- Bridging Osaurus's native plugins into an existing MCP client via osaurus mcp
- Keeping AI tool access and context on-device instead of routing through third-party servers
Available tools
osaurus mcp
Bridges Osaurus's native plugins to any MCP client over stdio.
osaurus serve
Starts the local Osaurus server that hosts models and plugins.
Remote MCP providers
Connects to and aggregates tools from external MCP servers (e.g. GitHub, Linear, Notion) into one local toolset.
Native plugins (Mail, Calendar, Git, Filesystem, Vision, ...)
Built-in macOS capabilities exposed as callable tools without extra setup.
Frequently asked questions
Does it run cloud models too, or only local ones?
Both. Osaurus can run models locally on Apple Silicon and route requests to cloud providers, working as one harness regardless of where a given model lives.
Can I connect tools I already use elsewhere, like GitHub or Notion?
Yes. Osaurus also acts as an MCP client, aggregating tools from around 25 well-known remote MCP providers with automatic OAuth, on top of its own 20+ native plugins.