Worktrees & siblings
OAK correlates parallel agents across the git worktrees of one repository.
Serious agent work spreads across git worktrees — one checkout per parallel attempt, so three agents can try the same task without stashing or branch-juggling. OAK's job is to make those parallel checkouts read as one account rather than three unrelated ones.
Worktree
A git worktree is a separate checkout of one repository. Claude Code keys its sessions by directory, so sessions in two worktrees of one repository would otherwise appear unrelated. The observatory correlates them by reading each worktree's .git pointer files as plain files — never by running the git binary, so it stays fast and side-effect-free.
Sibling
A sibling is another session in the same project — or, when the view is widened to the repository, in any of its worktrees. Siblings are how OAK presents parallel attempts: side by side, each with its own change map and review state.
When siblings touch the same file, OAK flags it as a live conflict — but tracking is by path only. File names cross between agents; file contents never do.
The fleet ties them together
Every running agent across the repository's worktrees is unified into one board — the fleet. That's where you watch siblings race, see which is furthest along, and catch two of them heading for the same file before they collide.