openharness

OpenHarness runs a crowd of coding agents side by side and lets you watch them all from one desktop app. Claude Code, Codex, Cursor, OpenCode, Copilot and nine more each get their own tmux pane and, optionally, their own git worktree, across any machines you link over an encrypted connection. It comes from Autonomous, the company better known for standing desks, and the app is MIT and free to download.

Install is a curl script from Autonomous's own domain, and the daemon auto-updates. macOS is the main platform; Linux is in progress and Windows isn't there yet. It doesn't wrap the agents, so each one still needs its own subscription or API key.

Right now you need an Autonomous account even for purely local use, and the project's own docs list removing that as an outstanding requirement. Hosted machines beyond one small free one are the paid part, with no public price list yet. Solo: worth a try if you juggle several agents. Teams: wait for account-free local mode. Claude Squad (smtg-ai/claude-squad) does the tmux-and-worktrees job with no account at all.

The catch: "open source, all of it" is overstated. The sign-in service and the hosted machine manager are closed, so you can't run the whole thing yourself. And until a September 29, 2026 commit, the desktop and phone apps sent usage analytics like app opens, sign-ins and agents created.