gh-stack

gh stack is a GitHub CLI extension for managing stacked branches and pull requests. A stack is an ordered list of branches where each branch builds on the one below it, rooted on a trunk branch (typically the repo's default branch). Each branch maps to one PR whose base is the branch below it, so reviewers see only the diff for that layer.

main (trunk)
 └── auth-layer     → PR #1 (base: main)            - bottom (closest to trunk)
  └── api-endpoints → PR #2 (base: auth-layer)
   └── frontend     → PR #3 (base: api-endpoints)   - top (furthest from trunk)

The bottom of the stack is the branch closest to the trunk, and the top is the branch furthest from the trunk. Each branch inherits from the one below it. Navigation commands (up, down, top, bottom) follow this model: up moves away from trunk, down moves toward it.

When to use this skill

Use this skill when the user wants to:

• Break a large change into a chain of small, reviewable PRs
• Create, rebase, push, or sync a stack of dependent branches
• Navigate between layers of a branch stack
• View the status of stacked PRs
• Tear down and rebuild a stack to remove, reorder, or rename branches

Prerequisites

The GitHub CLI (gh) v2.0+ must be installed and authenticated. Install the extension with:

gh extension install github/gh-stack

Before using gh stack, configure git to prevent interactive prompts:

git config rerere.enabled true           # remember conflict resolutions (skips prompt on init)
git config remote.pushDefault origin     # if multiple remotes exist (skips remote picker)

Agent rules

All gh stack commands must be run non-interactively. Every command invocation must include the flags and positional arguments needed to avoid prompts, TUIs, and interactive menus. If a command would prompt for input, it will hang indefinitely.

1. Always supply branch names as positional arguments to init, add, and checkout. Running these commands without arguments triggers interactive prompts. Branch names are used exactly as given — a name is never prefixed or transformed, so gh stack add refactor/foo creates a branch named refactor/foo.
2. Always use --auto with gh stack submit to auto-generate PR titles. Without --auto, submit prompts for a title for each new PR.
3. Always use --json with gh stack view. Without --json, the command launches an interactive TUI that cannot be operated by agents. There is no other appropriate flag — always pass --json.
4. Handle multiple remotes. If more than one remote is configured, pre-configure git config remote.pushDefault origin, or pass --remote <name> to the commands that accept it: push, submit, sync, rebase, and link. checkout, modify, and trunk resolve a remote but have no --remote flag — they rely on remote.pushDefault. With multiple remotes and no configured default, these commands exit with an error in non-interactive mode.
5. Avoid branches shared across multiple stacks. If a branch belongs to multiple stacks, commands exit with code 6. Check out a non-shared branch first.
6. Plan your stack layers by dependency order before writing code. Foundational changes (models, APIs, shared utilities) go in lower branches; dependent changes (UI, consumers) go in higher branches. Think through the dependency chain before running gh stack init.
7. Use standard git add and git commit for staging and committing. This gives you full control over which changes go into each branch. The -Am shortcut is available but should not be the default approach—stacked PRs are most effective when each branch contains a deliberate, logical set of changes.
8. Navigate down the stack when you need to change a lower layer. If you're working on a frontend branch and realize you need API changes, don't hack around it at the current layer. Navigate to the appropriate branch (gh stack down, gh stack checkout, or gh stack bottom), make and commit the changes there, run gh stack rebase --upstack, then navigate back up to continue.
9. Use gh stack link for external tool workflows. When branches are managed by an external tool (jj, Sapling, etc.), use gh stack link branch-a branch-b. link does not rely on local tracking state and is intended for API-driven PR and stack management. Provide at least two branches/PRs to create or update a stack, or a stack number followed by the new branches/PRs to append them to the top of an existing stack (e.g. gh stack link 7 branch-c).
10. Use gh stack merge --yes to merge stacked PRs. gh pr merge does not work with stacked PRs. In a non-interactive terminal gh stack merge runs without prompting and merges the entire stack (bottom to top) atomically; pass --yes to be explicit. Scope the merge by passing a pull request number (gh stack merge 42 --yes merges everything up to and including PR #42) or a stack number (gh stack merge 7 --yes, which needs no local checkout). Choose the method with --squash, --rebase, --merge, or --merge-method <method>; without one, the last-used method is used. The merge is all-or-nothing — if any PR can't be merged, none are, and the failure reason is reported. Only basic pull request state is checked before merging (open and not a draft); bypassing merge requirements is not supported for stacks. If the base branch uses a merge queue, the stack is added to the queue instead of merging directly: the queue chooses the merge method (any method you pass is ignored with a warning), and the pull requests are added to the queue together but merge as the queue processes them, so they may land in separate groups rather than all at once.

Never do any of the following — each triggers an interactive prompt or TUI that will hang:

• ❌ gh stack view or gh stack view --short — always use gh stack view --json
• ❌ gh stack submit without --auto — always use gh stack submit --auto
• ❌ gh stack init without branch arguments — always provide branch names
• ❌ gh stack add without a branch name — always provide a branch name
• ❌ gh stack checkout without an argument — always provide a PR number or branch name
• ❌ gh stack checkout <pr-number> when a different local stack already exists on those branches — this triggers an unbypassable conflict resolution prompt; use gh stack unstack --local first to remove the local tracking state (this keeps the stack on GitHub intact), then retry the checkout

Thinking about stack structure

Each branch in a stack should represent a discrete, logical unit of work that can be reviewed independently. The changes within a branch should be cohesive—they belong together and make sense as a single PR.

Dependency chain

Stacked branches form a dependency chain: each branch builds on the one below it. This means foundational changes must go in lower (earlier) branches, and code that depends on them goes in higher (later) branches.

Plan your layers before writing code. For example, a full-stack feature might be structured like this (use branch names relevant to your actual task, not these generic ones):

main (trunk)
 └── data-models    ← shared types, database schema
  └── api-endpoints ← API routes that use the models
   └── frontend-ui  ← UI components that call the APIs
    └── integration ← tests that exercise the full stack

This is illustrative — choose branch names and layer boundaries that reflect the specific work you're doing. The key principle is: if code in one layer depends on code in another, the dependency must be in the same branch or a lower one.

Branch naming

Choose a clear, descriptive branch name for each layer that reflects the concern it contains (e.g., auth, api-routes, frontend). Branch names are used exactly as you provide them to init and add — nothing is prepended or transformed. Slashes are allowed and are treated as part of the name (e.g., gh stack add refactor/foo creates a branch named refactor/foo).

Staging changes deliberately

The main reason to use git add and git commit directly is to control which changes go into which branch. When you have multiple files in your working tree, you can stage a subset for the current branch, commit them, then create a new branch and stage the rest there:

# You're on data-models with several new files in your working tree.
# Stage only the model files for this branch:
git add internal/models/user.go internal/models/session.go
git commit -m "Add user and session models"

git add db/migrations/001_create_users.sql
git commit -m "Add user table migration"

# Now create a new branch for the API layer and stage the API files there:
gh stack add api-routes # created & switched to the api-routes branch
git add internal/api/routes.go internal/api/handlers.go
git commit -m "Add user API routes"

This keeps each branch focused on one concern. Multiple commits per branch are fine — the key is that all commits in a branch relate to the same logical concern, and changes that belong to a different concern go in a different branch.

When to create a new branch

Create a new branch (gh stack add) when you're starting a different concern that depends on what you've built so far. Signs it's time for a new branch:

• You're switching from backend to frontend work
• You're moving from core logic to tests or documentation
• The next set of changes has a different reviewer audience
• The current branch's PR is already large enough to review

One stack, one story

Think of a stack from the reviewer's perspective: the stack of PRs should tell a cohesive story about a feature or project. A reviewer should be able to read the PRs in sequence and understand the progression of changes, with each PR being a small, logical piece of the whole.

When to use a single stack: All the branches are part of the same feature, project, or closely related effort. Even if the work spans multiple concerns (models, API, frontend), they're all building toward the same goal.

When to create a separate stack: The work is unrelated to your current stack — a different feature, a bug fix in an unrelated area, or an independent refactor. Don't mix unrelated work into a single stack just because you happen to be working on both. Start a new stack with gh stack init or switch to an existing stack with gh stack checkout for each distinct effort.

Small, incidental fixes (e.g., fixing a typo you noticed) can go in the current stack if they're trivial. But if a change grows into its own project, it deserves its own stack.

Quick reference

Task	Command
Create a stack	gh stack init auth
Create a stack of multiple branches	gh stack init auth api frontend
Adopt existing branches	gh stack init existing-branch-a existing-branch-b
Set custom trunk	gh stack init --base develop branch-a
Add a branch to stack	gh stack add api-routes
Add branch + stage all + commit	gh stack add -Am "message" api-routes
Push branches to remote	gh stack push
Push to specific remote	gh stack push --remote origin
Push branches + create draft PRs	gh stack submit --auto
Create PRs as ready for review	gh stack submit --auto --open
Sync (fetch, rebase, push)	gh stack sync
Sync with specific remote	gh stack sync --remote origin
Sync and prune merged branches	gh stack sync --prune
Rebase entire stack	gh stack rebase
Rebase upstack only	gh stack rebase --upstack
Rebase without trunk	gh stack rebase --no-trunk
Continue after conflict	gh stack rebase --continue
Abort rebase	gh stack rebase --abort
View stack details (JSON)	gh stack view --json
Switch branches up/down in stack	gh stack up [n] / gh stack down [n]
Switch to top/bottom branch	gh stack top / gh stack bottom
Check out by stack number	gh stack checkout 7
Check out by PR	gh stack checkout 42
Check out by branch (local only)	gh stack checkout feature-auth
Tear down the current stack to restructure it	gh stack unstack
Tear down a specific stack by number	gh stack unstack 7
Merge the whole current stack	gh stack merge --yes
Merge a stack by number	gh stack merge 7 --yes
Merge up to a specific PR	gh stack merge 42 --yes
Merge with a specific method	gh stack merge --yes --squash

---

Workflows

End-to-end: create a stack from scratch

# 1. Initialize a stack with the first branch
gh stack init auth
# → creates auth and checks it out

# 2. Write code for the first layer (auth)
cat > auth.go << 'EOF'
package auth

func Middleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        // verify token
        next.ServeHTTP(w, r)
    })
}
EOF

# 3. Stage and commit using standard git commands
git add auth.go
git commit -m "Add auth middleware"

# You can make multiple commits on the same branch
cat > auth_test.go << 'EOF'
package auth

func TestMiddleware(t *testing.T) {
    // test auth middleware
}
EOF
git add auth_test.go
git commit -m "Add auth middleware tests"

# 4. When you're ready for a new concern, add the next branch
gh stack add api-routes
# → creates api-routes

# 5. Write code for the API layer
cat > api.go << 'EOF'
package api

func RegisterRoutes(mux *http.ServeMux) {
    mux.HandleFunc("/users", handleUsers)
}
EOF
git add api.go
git commit -m "Add API routes"

# 6. Add a third layer for frontend
gh stack add frontend
# → creates frontend

cat > frontend.go << 'EOF'
package frontend

func RenderDashboard(w http.ResponseWriter) {
    // calls the API endpoints from the layer below
}
EOF
git add frontend.go
git commit -m "Add frontend dashboard"

# ── Stack complete: auth → api-routes → frontend ──

# 7. Push everything and create PRs (drafts by default)
gh stack submit --auto

# 8. Verify the stack
gh stack view --json

Shortcut: If you prefer a faster flow, gh stack add -Am "message" branch-name combines staging, committing, and branch creation into one command. This is useful for single-commit layers but bypasses deliberate staging.

Making mid-stack changes

This is a critical workflow for agents. When you're working on a higher layer and realize you need to change something in a lower layer (e.g., you're building frontend components but need to add an API endpoint), navigate down to the correct branch, make the change there, and rebase.

# You're on frontend but need to add an API endpoint

# 1. Navigate to the API branch
gh stack down
# or: gh stack checkout api-routes

# 2. Make the change where it belongs
cat > users_api.go << 'EOF'
package api

func handleGetUser(w http.ResponseWriter, r *http.Request) {
    // new endpoint the frontend needs
}
EOF
git add users_api.go
git commit -m "Add get-user endpoint"

# 3. Rebase everything above to pick up the change
gh stack rebase --upstack

# 4. Navigate back to where you were working
gh stack top
# or: gh stack checkout frontend

# 5. Continue working — the API changes are now available

Why this matters: If you make API changes on the frontend branch, those changes will end up in the wrong PR. The API PR won't include them, and the frontend PR will have unrelated API diffs mixed in. Always put changes in the branch where they logically belong.

Modify a mid-stack branch and sync

When you need to revisit a branch after the initial creation (e.g., responding to review feedback):

# 1. Navigate to the branch that needs changes
gh stack bottom
# or: gh stack checkout auth
# or: gh stack checkout 42  (by PR number)

# 2. Make changes and commit
cat > auth.go << 'EOF'
package auth
// updated implementation
EOF
git add auth.go
git commit -m "Fix auth token validation"

# 3. Rebase everything above this branch
gh stack rebase --upstack

# 4. Push the updated stack
gh stack push

Routine sync after merges

# Single command: fetch, rebase, push, sync PR and stack state
gh stack sync

# Sync and automatically clean up local branches for merged PRs
gh stack sync --prune

Note for agents: In non-interactive environments, the prune prompt is not shown. Use --prune explicitly to delete local branches for merged PRs.

Note for agents: sync also mirrors the stack on GitHub locally. If PRs were added to the stack on github.com, their branches are pulled down and appended to the local stack automatically. If the local and remote stacks have diverged (you changed the local stack while the remote stack changed differently), sync can only prompt to resolve it in an interactive terminal — in non-interactive environments it aborts the sync (nothing is pushed or updated) and exits successfully with ℹ Sync aborted. Resolve a divergence by unstacking and recreating the stack.

Squash-merge recovery

When a PR is squash-merged on GitHub, the original branch's commits no longer exist in the trunk history. gh stack detects this automatically and uses git rebase --onto to correctly replay remaining commits.

# After PR #1 (auth) is squash-merged on GitHub:
gh stack sync
# → fetches latest, detects the merge, fast-forwards trunk
# → rebases api-routes onto updated trunk (skips merged branch)
# → rebases frontend onto api-routes
# → pushes updated branches
# → reports: "Merged: #1"

# Verify the result
gh stack view --json
# → auth shows "isMerged": true, "state": "MERGED"
# → api-routes and frontend show updated heads

If sync hits a conflict during this process, it restores all branches to their pre-rebase state and exits with code 3. See Handle rebase conflicts for the resolution workflow.

Handle rebase conflicts (agent workflow)

# 1. Start the rebase
gh stack rebase

# 2. If exit code 3 (conflict):
#    - Parse stderr for conflicted file paths
#    - Read those files to find <<<<<<< / ======= / >>>>>>> markers
#    - Edit files to resolve conflicts
#    - Stage resolved files:
git add path/to/resolved-file.go

# 3. Continue the rebase
gh stack rebase --continue

# 4. If another conflict occurs, repeat steps 2-3

# 5. If unable to resolve, abort to restore everything
gh stack rebase --abort

Parsing --json output

# Get stack state as JSON
output=$(gh stack view --json)

# Check if any branch needs a rebase, and rebase if so
needs_rebase=$(echo "$output" | jq '[.branches[] | select(.needsRebase == true)] | length')
if [ "$needs_rebase" -gt 0 ]; then
  echo "Branches need rebase, rebasing stack..."
  gh stack rebase
fi

# Get all open PR URLs
echo "$output" | jq -r '.branches[] | select(.pr.state == "OPEN") | .pr.url'

# Find merged branches
echo "$output" | jq -r '.branches[] | select(.isMerged == true) | .name'

# Get the current branch
echo "$output" | jq -r '.currentBranch'

# Check if the stack is fully merged (all branches merged)
echo "$output" | jq '[.branches[] | .isMerged] | all'

Restructure a stack (remove a branch, reorder, or rename)

Use unstack to tear down the stack, make structural changes, then re-init:

# 1. Remove the local tracking and the GitHub stack grouping (PRs are NOT deleted)
gh stack unstack

# 2. Make structural changes — e.g. delete a branch, reorder, rename
git branch -m old-branch-1 new-branch-1

# 3. Re-create the stack with the new structure
gh stack init --base main new-branch-1 new-branch-2 new-branch-3

---

Commands

Initialize a stack — gh stack init

Creates a new stack. Always provide at least one branch name as a positional argument — running without branch arguments triggers interactive prompts that agents cannot use.

gh stack init [flags] <branches...>

# Create a stack with a new branch
gh stack init auth
# → creates auth and checks it out

# Create a stack with new branches
gh stack init branch-a branch-b branch-c

# Use a different trunk branch
gh stack init --base develop branch-a branch-b

# Adopt existing branches into a stack (handled automatically if the branches exist)
gh stack init branch-a branch-b branch-c

Flag	Description
-b, --base <branch>	Trunk branch (defaults to the repo's default branch)

Behavior:

• Branch names are created exactly as given (slashes are allowed and kept as-is)
• Creates any branches that don't already exist (branching from the trunk branch)
• Existing branches are adopted automatically; missing branches are created from the trunk
• Checks out the last branch in the list
• Enables git rerere so conflict resolutions are remembered across rebases. On first run in a repo, this may trigger a confirmation prompt — pre-configure with git config rerere.enabled true to avoid it

---

Add a branch — gh stack add

Add a new branch on top of the current stack. Must be run while on the topmost branch (or the trunk if the stack has no branches yet). Always provide a branch name — running without one triggers an interactive prompt.

gh stack add [flags] <branch>

Recommended workflow — create the branch, then use standard git:

# Create a new branch and switch to it
gh stack add api-routes

# Write code, stage deliberately, and commit
git add internal/api/routes.go internal/api/handlers.go
git commit -m "Add user API routes"

# Make more commits on the same branch as needed
git add internal/api/middleware.go
git commit -m "Add rate limiting middleware"

Shortcut — stage, commit, and branch in one command:

# Create a new branch, stage all changes, and commit
gh stack add -Am "Add API routes" api-routes

# Create a new branch, stage tracked files only, and commit
gh stack add -um "Fix auth bug" auth-fix

Flag	Description
-m, --message <string>	Create a commit with this message
-A, --all	Stage all changes including untracked files (requires -m)
-u, --update	Stage tracked files only (requires -m)

Behavior notes:

• -A and -u are mutually exclusive.
• When the current branch has no commits (e.g., right after init), add -Am commits directly on the current branch instead of creating a new one.
• Branch names are used verbatim. gh stack add refactor/foo creates a branch named refactor/foo — names are never prefixed or transformed. When -m is given without a branch name, the name is auto-generated from the commit message in date+slug format (e.g., 03-24-add_api_routes).
• If called from a branch that is not the topmost in the stack, exits with code 5: "can only add branches on top of the stack". Use gh stack top to switch first.
• Uncommitted changes: When using gh stack add branch-name without -Am, any uncommitted changes (staged or unstaged) in your working tree carry over to the new branch. This is standard git behavior — the working tree is not touched. Commit or stash changes on the current branch before running add if you want a clean starting point on the new branch.

---

Push branches to remote — gh stack push

Push active stack branches to the remote.

gh stack push [flags]

# Push all branches
gh stack push

# Push to specific remote
gh stack push --remote upstream

Flag	Description
--remote <name>	Remote to push to (use if multiple remotes exist)

Behavior:

• Pushes all active (non-merged, non-queued) branches in one non-atomic multi-ref push with explicit per-branch --force-with-lease checks
• Some branches may update if another is rejected; fix the rejected branch and rerun the command
• Does not create or update pull requests — use gh stack submit for that