Stack

Stack

ARGUMENTS: $ARGUMENTS

Step 0 — Refuse if not in a worktree workspace

Stacking is only supported in worktree workspaces. The stacked workspace is created via git worktree add in the project's on-disk git repo, and only worktree source workspaces share that git (so the current branch is locally resolvable). From a clone or in-place workspace, the stacked workspace cannot find the current branch as a ref — pushing to origin doesn't help because git worktree add doesn't DWIM a bare branch name to origin/<branch>.

Check the strategy first:

sculpt workspace show "$SCULPT_WORKSPACE_ID" --json | jq -r .strategy

If the result is not WORKTREE, stop and tell the user (using their strategy name):

Stacking isn't supported from a <strategy> workspace — the stacked workspace wouldn't be able to base off your current branch. Use /sculptor-experimental:handoff (new agent in the same workspace) to continue this work, or move it into a worktree workspace first.

Only proceed if the strategy is WORKTREE.

Steps 1–4 — Hand off into a new workspace

Stacking is a handoff into a new workspace, specialized for building on top of the current branch. Follow the /sculptor-experimental:handoff skill — invoke it and do what its "new workspace" path does (run the pre-flight commit check, compose a self-contained context-summary prompt, create the workspace + agent with sculpt run, then report the new IDs) — with these differences:

1. Don't ask which destination. Stacking always creates a new workspace, so skip handoff's Step 1 question entirely.
2. Target the current branch. Pass --target-branch <current-branch> in addition to --branch <current-branch>. This scopes the new workspace's diff/MR to only the changes stacked on top of the current branch, instead of the repo's default target (e.g. main). This is the defining trait of a stack.

So the create command (handoff's Step 4 new-workspace command, with --target-branch added) is:

git rev-parse --abbrev-ref HEAD   # current branch = source AND target

sculpt run \
  --strategy worktree \
  --branch "<current-branch>" \
  --target-branch "<current-branch>" \
  --name "<short task name>" \
  --json \
  "<context-summary prompt>"

Use sculpt run, not sculpt workspace create. sculpt run creates the workspace, its agent, and the git worktree in one step. sculpt workspace create only registers a workspace record — no agent, no checkout — so it renders as a blank screen in the UI. To add an agent to an already-empty workspace, run sculpt agent create -w <ws_id> -p "...".