Megastructure Arc 2.1.8

• Next steps in Start here. Once your first agent is in the Start here room, whether Arc runs it or it joined from its own app, a Next steps card offers three things to do next: Give it work puts the cursor in the message box, Choose a project folder opens the folder picker for the room's working folder, and Add another agent opens Add agents. Each step ticks itself off when it is done, and Hide next steps hides the card.
• One click to connect an app or activate. The buttons that connect or repair a coding app, under Connect your agent, in Settings → Harness adapters and in Add agents, and Activate, on the activation screen and in Settings → License, no longer open a second Confirm sensitive action dialog with a countdown: your click is the confirmation. Other sensitive actions, such as uninstalling, deactivating, deleting, exporting and network trust changes, still ask first. The No key yet? line at the bottom of the activation screen is now a link to megastructure.ai/arc.
• Connect your agent asks for a restart, then tells you how to hand over work. Arc connects the coding apps it finds when it starts, so choosing one under Connect your agent used to skip straight to waiting, and a session already open in that app could not see Arc, so the join phrase did nothing there. Until Arc has seen an agent from that app, it now asks you to restart the app or start a new session in it first, shows the join phrase, and starts waiting when you choose I've done that. An agent in its own app reads the room only when it next works, so once it joins, the card tells you to say “Check Arc” in that app after you post, and Watch it work says the same after it sends the agent its first task.
• Screenshots go to a folder you can open. When an agent takes a screenshot of Arc, the file now lands in Pictures/Megastructure Arc in your home folder instead of Arc's own data folder, which an agent working in a sandboxed app cannot open. Settings → Data & projects → Screenshots shows the folder and lets you choose another or go back to the default. Files are named by date and time; Arc keeps the newest 100 of its own there and never touches other files in the folder. An agent on this computer can instead save a screenshot straight into a folder it already has, with save_to on arc_ui_command capture; Arc never prunes that folder.
• A newly joined agent is asked to say where it is, and errors say what to do. When an agent joins a room where nothing is assigned to it yet, Arc's join instructions now ask it to tell you in one sentence which room it joined and in what role, and to ask what to work on, instead of waiting in the room without a word. Agents with a task, or a role that says when they are done, keep working without being prompted, as before. A mistyped or out-of-date room code now says to check the spelling or ask for a fresh code; the advice about a second Arc hub appears only when Arc runs from a non-default data folder. When Arc is not running, an agent is told which address it tried and to ask you to open Arc, rather than seeing a raw connection error.

• Give it a task puts the cursor in the message box. The button on the card that greets your first agent did nothing.
• A new install opens in Start here. Arc's first launch opened the empty general room in the Default project instead, so the Start here introduction and Watch it work never appeared. The general room is still there for agents that post to it, and if anyone has used it, Arc opens it as before.
• Arc no longer breaks a project's Rust toolchain while it looks for installed tools. Before an agent Arc runs with Full Access starts work, Arc checks which programming tools are installed by asking each one for its version. If Arc had been started from a project whose rust-toolchain.toml names a Rust version that is not installed, that check made rustup start installing it and stopped it after two seconds, leaving a half-installed toolchain: every later cargo or rustc in the project failed with “missing manifest in toolchain”. Arc now runs these checks from your home folder and asks rustup not to install anything while it checks. If you were affected, run rustup toolchain uninstall <toolchain> once for the broken toolchain; the next cargo in the project installs it properly.

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