Galactic is an open-source Mac app, built by one developer, for people who let several AI coding assistants work on the same software project at once. It gives each assistant its own copy of the code to work in and its own local network address, so they don't overwrite each other's files or collide when they test the website they are building.
What problem does it address?
A coding agent such as Claude Code edits files in a folder on the developer's computer. Start two agents in the same folder and one can overwrite the other's changes. Git, the version control system most developers use, has an answer: a worktree. According to the Git documentation, a repository "can support multiple working trees, allowing you to check out more than one branch at a time". Each agent then works in its own folder on its own branch, and the work comes back together through a merge. One problem remains: two copies of the same web app both want the same port on the developer's machine.
How does Galactic work?
In March 2026 the README described a desktop app for macOS, built with Electron, with Windows and Linux support on the roadmap. Its main features:
- Worktrees in one click: Galactic creates a worktree for any branch, with its own workspace file for Cursor or VS Code.
- Network isolation: each environment gets its own loopback address (127.0.0.2, 127.0.0.3 and so on), so the same stack can run on the same ports several times over, without containers.
- Agent monitoring: Galactic runs an MCP server that shows active agent sessions from Cursor, VS Code, Claude and Codex in one place, and notifies you when a session finishes, takes too long or needs attention.
The agents themselves run in those editors and tools. Galactic prepares their workspaces and keeps track of their sessions. On 25 April 2026 the README made a newer mode the recommended one: Project Services, a local proxy on port 1355 that routes addresses of the form service.branch.project.localhost:1355 to the right service in the right worktree, with the loopback mode kept for existing setups.
How big is the project?
Galactic is a one-person project. Ido Lavi (GitHub: idolaman) created the repository on 9 November 2025 and publishes it under the AGPL-3.0 licence. In September 2026 it had 226 stars and one human contributor, and the last release by then, 1.0.33, dated from 30 May 2026. The blog post on building reliable multi-agent systems places it next to other ways of keeping parallel agents apart.
What does it leave unsolved?
Worktrees keep agents from overwriting each other's files. They do not prevent incompatible changes: those surface as merge conflicts when the branches come together, where a developer can see and resolve them. Galactic also runs only on a Mac, and a project with one maintainer can stall, so check its activity before a team depends on it.
Example
Suppose a developer has one agent add a database table and another restyle the front end. In Galactic they create two worktrees, one per branch. Each gets its own address, so all three copies of the app can run on port 3000 at the same time:
1 /repo/main branch main 127.0.0.1:3000 2 /repo/agent-a branch agent-a 127.0.0.2:3000 3 /repo/agent-b branch agent-b 127.0.0.3:3000
When both agents are done, the developer reviews the two branches and merges them. If both changed the same lines, Git reports a conflict at that point.