Megastructure Arc 2.0.0

• Computer use on the Mac: in a Full Access room, an Arc-managed agent whose model can see images can see the screen and click, type, scroll, and drag in any app. Ask in plain words; the first time, macOS asks you to allow Megastructure Arc under Accessibility and Screen Recording. The right rail shows the live screen with Pause, Resume, and Stop, Control-Option-Command-Period stops the agent at once, and touching the mouse or keyboard pauses it until you stop. Agents never answer macOS security or permission dialogs, never type into password fields, and never log out or lock the Mac. Safe rooms have no computer use, and Windows does not offer it.
• Stop an agent’s turn from the chat: every working agent shows Stop under the composer, so a long turn no longer has to be waited out. Every message has a menu with Delete; the room keeps a small “deleted” marker, the audit trail keeps a record, and an Arc-managed agent also forgets a deleted exchange.
• Claude models on an Anthropic connection now use Anthropic’s own Messages API, bringing preserved thinking, server-side context management, and prompt caching.
• Refreshing a self-hosted server in Settings checks whether each model can see images, and Settings labels each model as text only, sees images, or able to use the computer. Agents on models that can see receive images.
• Local models start faster: a local agent’s first call lists only the tools it needs to begin and finds the rest with search. On ds4-server a Full Access agent’s first call dropped from 3,620 to 1,922 tokens and its cold start from about 40 to 20 seconds.

• The image check for a connection reads the model’s answer, so a server that silently drops images no longer marks a model that can’t see as able to see, and Grok models are no longer marked unable to see. Models that point on a 0–999 grid (Gemini) are no longer told that coordinates are pixels.
• Local agents and GGUF models set up before 1.9.9 work again on Windows and macOS: Arc repoints them at the current install’s llama.cpp runtime on startup. Custom runtime paths are left alone.
• Windows: updating from 1.9.8 or earlier keeps your Start menu and desktop shortcuts.
• Switching rooms no longer makes the Arc Loops bar jump for a moment.

Windows 10/11 (64-bit), or macOS 11+ on Apple Silicon. Bundled Local AI requires macOS 26+. Computer use requires macOS 14+.