JetBrains ships ThinkRail, an agentic IDE that gives each coding agent its own git worktree and branch
Synopsis
JetBrains has released ThinkRail, an agentic IDE that places coding agents in separate workspaces cut from a git repository, each with its own branch and working directory, so agents can work in parallel without touching the developer's checkout. It wraps the pi coding agent in an editor, terminals and review surface, and lets the agent keep project intent through a graph of SPEC.md files beside the code. Merging the good branch and deleting the rest closes the loop.
Interpretation
Coding agents no longer edit code directly in the developer's current checkout; each works in a workspace cut from the git repository. The prior arrangement had agents and developers sharing one checkout, so changes interfered with each other. ThinkRail opens any git repository as a project and cuts workspaces from it as git worktrees, each with its own branch and working directory, so agents work in parallel without touching the checkout.
Workspaces have a lifecycle: finished or dormant ones settle onto a per-project shelf and return when needed. Cleaning up parallel branches previously required deciding by hand which to keep and which to delete. When a workspace's pull request merges or closes, or after a quiet week, it settles onto the shelf on its own and comes back the moment work resumes in it.
The agent gains durable project knowledge from a graph of spec files beside the code, not only from a single session's context. Previously, intent survived only in the conversation record after a session ended. A connected graph of SPEC.md files lives beside the code, and the agent reads, searches and maintains it through dedicated spec_* tools; a read-only Specs tool renders the graph as a tree in the workbench.
The agent can also call tools beyond the shell, including web research and diagrams, option comparisons and file previews rendered directly in the chat. Previously the agent's means were largely limited to the command line. When the agent proposes a UI change it shows a before/after mockup in the chat that can be commented on like a diff; Settings lists the ThinkRail extensions the agent gets and lets each be switched off.
Perspective
The workflow targets developers who use git repositories as projects and already work with the pi coding agent; workspace isolation, the spec graph, skills and MCP server connections are all described in that setting. The material states that full extension support comes next, so ThinkRail can create the tools it needs based on how the user actually works.
The material describes features as a product introduction and reports no controlled experiment or quantitative metric, so how these workflows perform on real projects is not yet known. Extension support is presented as a next step rather than an existing capability.