Gh Stack

GitHub Stacks

Use GitHub's official gh stack extension for linear stacks of dependent branches and pull requests. Each branch builds on the branch below it, and each pull request targets that immediate parent so reviewers see one layer's diff.

Load git-context for branch and rebase operations. Load git-commit only after the user explicitly requests a commit or push.

Safety And Authorisation

• Inspect with gh stack view --json before and after every mutation.
• Do not commit through gh stack add -m, -A, or -u, and never run raw git commit. Commit only after explicit authorisation through dot git-commit, following the git-commit skill.
• Treat push, submit, sync, and branch arguments passed to link as push operations. Run them only when the user explicitly authorises that push.
• submit and link can create pull requests and generate or change titles, descriptions, and base branches. Obtain explicit consent for those specific PR changes before running them; permission to create a PR alone does not authorise its description.
• Treat rebase, modify, unstack, and rebuilding local tracking as history or stack-structure rewrites. Run them only when requested or when the user approves the explained recovery operation.
• Run merge only after explicit merge authorisation for the named stack or PR range. Never infer merge permission from approval to push or submit.
• Preserve unrelated worktree changes. Structural operations require a clean tree; do not stash, discard, or absorb user changes without permission.
• Never use plain force push. Stack pushes use per-branch --force-with-lease; stop if a lease is rejected.

Agent-Safe Operation

Avoid commands that open prompts or TUIs:

• Use gh stack view --json, never bare view or view --short.
• Treat view as best-effort PR-state refresh as well as inspection.
• Give branch names to init and add.
• Give a stack number, PR number, PR URL, or branch to checkout.
• Do not run interactive modify. Explain the intended structure and use the explicit non-interactive recovery path only after approval.
• If multiple remotes exist, pass --remote <name> where supported. Do not change remote.pushDefault merely to avoid a prompt.

The extension must be installed and authenticated:

gh extension install github/gh-stack
gh stack --help

Installation is a separate system change and requires the user's request or approval. Verify command flags against live help because gh stack is in public preview.

Choose The Right Operation

link does not establish local stack tracking. Use it for branches managed by another tool or when the user explicitly wants remote-only linking. Use init/submit for a locally managed stack.

For numeric checkout targets, resolution is stack number, then PR number, then branch name. Prefer an explicit PR URL or branch when a number could be ambiguous.

Build A Stack

1. Plan one coherent story in dependency order before implementing it, and create the stack first when the work is already known to need layers. Foundational changes belong below their consumers; unrelated work belongs in another stack. Prefer <topic>/<concern> branch names unless repository conventions differ.

2. Confirm the worktree and branch context, then initialise with explicit branch names:

   gh stack init --base <trunk> <bottom-branch> [higher-branches...]
   

3. Implement and verify one independently reviewable layer at a time.

4. When authorised to commit, use dot git-commit on the exact paths.

5. Add the next branch from the current top:

   gh stack add <next-branch>
   

6. When the user separately authorises pushing and the generated PR metadata, submit non-interactively, then verify:

   gh stack submit --auto --remote <remote>
   gh stack view --json
   

New PRs created with --auto default to draft unless --open is supplied. Do not use --open unless the user asks to mark them ready for review. init also enables Git rerere for the repository. Do not make additional Git configuration changes without authorisation. If every PR in the submitted stack has already merged, submission creates a new stack for remaining branches.

Fix A Lower Layer

Make a correction on the branch that owns it, not as an upstack workaround:

1. Navigate to the owning branch with down, bottom, or explicit checkout.

2. Make and verify the correction.

3. Commit only through the authorised dot git-commit workflow.

4. With approval to rewrite the upstack branches, run:

   gh stack rebase --upstack
   

5. With separate push authorisation, run gh stack push, then verify with gh stack view --json.

Synchronise And Recover

gh stack sync performs fetch, reconciliation, possible cascading rebase, push, PR-state sync, and remote-stack sync. It is not a read-only status check. Use it only with explicit push and rewrite authorisation.

After a squash merge, sync can replay remaining branches onto the updated trunk. If it reports a conflict, it restores the branches and exits with code 3. Then use the explicit rebase workflow:

gh stack rebase
# resolve files and stage only the resolutions
gh stack rebase --continue
# or restore the pre-rebase state
gh stack rebase --abort

Follow git-context for conflict resolution. Do not use raw interactive rebase continuation or editor workarounds when the extension owns the operation.

If local and remote stack composition diverge, stop and present the actual local/remote chains. Do not automatically choose the remote, delete the remote stack, or unstack. Those choices can discard tracking decisions.

Restructure Without The TUI

When a stack must be reordered, inserted into, renamed, folded, or have a layer removed:

1. Show the current view --json state and the proposed final branch order.

2. Obtain explicit approval for local/remote unstacking and history rewrites.

3. Use gh stack unstack (or --local when preserving GitHub grouping).

4. Recreate local tracking with explicit ordered branches:

   gh stack init --base <trunk> <bottom> <middle> <top>
   

5. Rebase as needed, then obtain explicit push and PR-metadata consent before submit --auto.

6. Verify branch order, heads, bases, and PR associations with gh stack view --json.

Merge

Before merging, verify every selected PR and every layer below it is open, non-draft, approved, current, and passing required checks. Then require an explicit stack number or PR endpoint and merge method:

gh stack merge <stack-number-or-pr-number> --yes --squash

Without a merge queue, the selected range is all-or-nothing. With a merge queue, the PRs are enqueued together but may land in separate groups, and the queue chooses the merge method.

Exit Codes

Limitations

• Stacks are linear and all branches must live in the same repository.
• link is additive and does not remove existing PRs from a remote stack.
• Branch arguments to link may be pushed automatically.
• submit generates PR titles and descriptions; edit them only with separate, specific user consent.
• push and submit are not atomic across every branch. Inspect partial success before retrying.
• GitHub's server-side rebase can create unsigned commits. Use the local extension workflow when signed commits are required.