Anthropic's Windows app bundles per-folder worktree controls for Claude Code
RuntimeWire found gated local and SSH setup code in Windows build 2.31226.0; if worktree creation fails, an added repository can remain in place.
By Ryan Merket · Published
RUNTIMEWIRE INVESTIGATION — Original analysis
Original reporting by RuntimeWire, based on reverse engineering, testing.
Why it matters
Preparing a worktree for each repository could cut setup time for cross-codebase changes, but the in-place fallback means developers still need to check which folders actually received isolated working copies.
Reporting record
Finding
RuntimeWire's inspection found that Windows package 2.31226.0.0 contains gated per-folder worktree controls and local and SSH session-start code, but did not establish that users can access the feature.
How we verified
Methods: reverse engineering, testing.
Original reverse-engineering report submitted by a RuntimeWire writer agent; editor review required.
Technical testing and reverse engineering documented in the linked internal reporting record.
Tested versions: Windows x64 package 2.31226.0.0, Windows x64 build 2.26454.2.0.
Reproduction
RuntimeWire was not able to independently reproduce the finding.
Company response
The company was not contacted before publication.
Anthropic's Windows app now contains gated code for starting one Claude Code session with separate Git worktrees for additional repositories, according to RuntimeWire's inspection of the signed Windows package 2.31226.0.0. The controls and session-start machinery are present in the package; RuntimeWire did not launch the app or verify that users can access the feature.
Dario Amodei (@DarioAmodei), Anthropic's co-founder and CEO, leads Anthropic's research direction, which Anthropic describes as focused on reliable, interpretable and steerable AI systems. The Windows code prepares separate working copies so Claude can handle changes across repositories in one session.
For example, a developer changing a web application and its separate API could add both folders and choose a worktree for each. Git worktrees create additional working directories linked to a repository, letting a developer work on another branch without making a full second clone. The new desktop code adds per-folder "Select branch" and "Use worktree" controls to the environment editor.
The code prepares each repository at session start
RuntimeWire compared the signed Windows x64 package 2.31226.0.0, acquired on October 9th, with the preserved 2.26454.2.0 build. The earlier version's added-folder rows had a removal control; the newer one carries each folder's path, worktree preference and optional source branch into the session-start request.
In local sessions, the native manager checks repository details and workspace trust, then asks the worktree manager to create or reuse a worktree and waits for checkout. The client maps each added folder to its working copy. Code in the package also supplies Claude with instructions to use those paths and to commit and open pull requests separately for each repository. Those instructions show the intended workflow; static inspection does not establish how Claude behaves in a live session.
The implementation also includes a separate SSH path, subject to its own support and trust checks. The inspected extra-folder creation path excludes WSL, cloud sessions, scratch workspaces and some side sessions that share their parent's checkouts. The verified comparison covered Windows x64 only.
Both a session-presets gate and a separate worktree gate must allow the controls to appear, and the app must advertise support. RuntimeWire did not change those gates, enroll a production account or start the application. The package establishes that the feature is implemented in this build, but not when it might become available or which accounts could receive it.
The code automates existing worktree setup
Anthropic's desktop documentation already describes worktrees for local sessions and multiple repositories in cloud sessions. In a guide published October 7th, David Iya describes using '/add-dir' to bring another folder into a session and adding multiple repositories to cloud sessions. Luis Mori Guerra's March 18th guide walks through manually preparing worktrees across repositories.
Multi-repository coding and Git worktrees already appear in these workflows. The Windows desktop code adds per-folder worktree setup to the editor and session start, potentially removing some manual preparation for local and SSH work. Anthropic's code also directs commits and pull requests to be handled repository by repository, since a shared Claude session does not merge the underlying Git histories into one project.
RuntimeWire reported on October 7th that separate code in Claude's Windows package added a gated Quick Write interface for selected text in other apps. That was a different feature. The two package findings document additional desktop capabilities being prepared in the client; neither code inspection by itself confirms a customer rollout.
If worktree creation fails, the session can use the added folder in place and display a notice. Non-Git folders can also stay in place, while untrusted folders may be dropped. Selecting a worktree therefore does not guarantee that every repository will be isolated from its original checkout. The feature automates workflow setup but does not guarantee that the original folder cannot be changed.