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Osaurus

Osaurus

The missing macOS LLM server
Run local and remote models on Apple Silicon with OpenAI-compatible APIs, tool calling, and a built-in plugin ecosystem. 10MB. Pure Swift.

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What is Osaurus?​

Osaurus is an all-in-one LLM server for macOS:

  • Local Models — Run MLX models on Apple Silicon with optimized inference
  • Remote Providers — Connect to OpenAI, Anthropic, Ollama, OpenRouter, and more
  • OpenAI, Anthropic & Ollama APIs — Drop-in compatible endpoints
  • MCP Server — Expose tools to Cursor, Claude Desktop, and other agents
  • Native Plugins — Swift and Rust tools, significantly faster than Python
  • Apple Foundation Models — System model on macOS 26+ (Tahoe)

Key Features​

MCP Server​

Osaurus is a full Model Context Protocol (MCP) server. Connect it to any MCP client—like Cursor, Claude Desktop, or your own agent—to give AI access to your installed tools.

{
  "mcpServers": {
    "osaurus": {
      "command": "osaurus",
      "args": ["mcp"]
    }
  }
}

Native Tools & Plugins​

Osaurus tools are pure native Swift and Rust implementations—significantly faster than Python-based MCPs.

AspectPython/uv BottleneckNative Swift Advantage
CPU SpeedInterpreter overhead + GILCompiled, multi-threaded
MemoryHigher baseline + GC pausesARC for precise control
Startupvenv + interpreter (~200ms)Binary load (under 10ms)

Official tools include browser automation, filesystem access, git operations, web search, and more. Browse the registry →

OpenAI, Anthropic & Ollama Compatible​

Drop-in replacement for existing tools and workflows:

  • OpenAI and Anthropic SDKs (Python & JavaScript)
  • LangChain, LlamaIndex, and other frameworks
  • Continue.dev, Cursor, and IDE integrations
  • Any OpenAI-compatible client

Apple Foundation Models​

Access Apple's system models with zero configuration on macOS 26+:

curl http://127.0.0.1:1337/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{"model": "foundation", "messages": [{"role": "user", "content": "Hello!"}]}'

Beautiful glass-styled chat overlay accessible via global hotkey (⌘;). No browser needed—just press and chat.

Developer Tools​

Built-in debugging via the Management window (⌘⇧M):

  • Insights — Real-time API monitoring, performance stats, inference metrics
  • Server Explorer — Interactive endpoint browsing and testing

Performance​

Osaurus delivers exceptional performance on Apple Silicon.

MetricOsaurusOllamaLM Studio
Time to First Token87ms33ms113ms
Throughput554 chars/s430 chars/s588 chars/s
Total Time1.24s1.62s1.22s

Benchmarked with Llama 3.2 3B Instruct 4bit, averaged over 20 runs on M2 Pro.

View detailed benchmarks →

System Requirements​

  • macOS 15.5 or later
  • Apple Silicon (M1, M2, M3, or newer)
  • Xcode 16.4 or later (only for building from source)
Apple Foundation Models

Apple Intelligence features require macOS 26 (Tahoe) or later.

Why Osaurus?​

People chose macOS because they care about craft. They deserve AI tools built with the same philosophy—software that feels intentional, fast, and native. Osaurus is the infrastructure that gets out of the way and lets a thousand lovable products bloom.

Our Philosophy​

We believe AI shouldn't repeat the mistakes of the cloud era. Here's what guides us:

  • Local-first, not local-only — Your machine is the source of truth. Run models locally when you want privacy and speed. Reach out to cloud providers when you need more power. The choice is yours.

  • The network is optional — Local-first software works offline, by design. Your AI tools should function on an airplane, in a coffee shop with unreliable WiFi, or simply when you don't want to depend on a server.

  • You retain ownership and control — The files on your machine are yours. The models you download are yours. We're not building another walled garden—we're building a foundation that respects your ownership.

  • Decentralized by design — AI shouldn't be locked behind platform gatekeepers. We're building infrastructure that gives people choices, not dependencies.

  • Free as in freedom — Osaurus is open source, MIT licensed. Some things should exist as public goods. This is one of them.

The Practical Benefits​

  • No API costs — Run inference locally, pay only for electricity
  • Complete privacy — All processing stays on your Mac
  • Native performance — 10MB Pure Swift, instant startup, no Electron
  • Zero dependencies — Single app, no Python environments to manage
  • Unified interface — One server for local models, cloud providers, and tools

Use Cases​

  • AI Agents — Connect MCP clients to local tools for autonomous workflows
  • Development — Test AI features without API costs
  • Code Generation — Offline programming assistance with tool access
  • Research — Analyze documents with complete privacy
  • Automation — Browser control, file operations, and more via plugins

Community​

Discord — Get help and share projects
GitHub — Report issues and contribute
Plugin Registry — Browse and submit tools
Good First Issues — Start contributing

Created by Dinoki Labs​

Osaurus is developed by Dinoki Labs, creators of native AI tools for macOS.

Get Started