ThinkRail

ThinkRail is an open-source, Apache-2.0 project from JetBrains InnovationHub positioned as an agentic IDE rather than a chat sidebar. You open a repository as a project, then carve out workspaces to work in. The pitch is that the environment improves as you use it, because project intent is captured in structured form instead of being retyped into prompts.

Each workspace is a git worktree with its own branch, files, terminals, and chats, so parallel agent tasks do not collide in one working directory. The editor is Monaco-based with tabs, terminals, and diffs, and you can run several agent conversations at once. A spec graph records what the project is meant to do, and the agent reads it when working.

It is aimed at developers who already think in branches and worktrees and want an agent inside a familiar editing surface. Teams exploring spec-driven development may find the spec graph useful for keeping intent reviewable. Casual users who just want a quick code answer will likely find the project-and-workspace model heavier than needed.

ThinkRail runs on macOS, Windows, and Linux, with desktop downloads and a command-line launcher that opens a browser UI. A sensible start is to open one repository, create a single worktree workspace, and let the agent work while you watch diffs before scaling to concurrent chats. Because it is open source, you can inspect how the spec graph and workspaces are implemented before adopting it.