# Stack

> Stack a new workspace on top of the current branch — a handoff into a NEW workspace whose new branch is based off, and targets, the current branch.

- Skill: `imbue-ai/stack` (Agent Skill)
- Install (CLI): `npx skillmds@latest add imbue-ai/stack`
- Raw SKILL.md: https://api.skillmd.com/api/skills/imbue-ai/stack/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: imbue-ai (https://skillmd.com/u/imbue-ai)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/imbue-ai/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:

```bash
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:

```bash
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 "..."`.