cascade-merge

name	cascade-merge
description	Cascade merge changes through a chain of dependent branches. Use when updating stacked/chained PRs, propagating changes from a parent branch to all downstream branches, or when the user mentions "cascade merge", "propagate changes", "update dependent branches", or "merge to downstream branches".
allowed-tools	Bash(gh pr list:*), Bash(jq:*), Bash(git checkout:*), Bash(git switch:*), Bash(git merge:*), Bash(git push origin:*), Bash(git status:*), Bash(git branch:*), Bash(git fetch:*)

Cascade Merge

Propagate changes from a source branch through all dependent branches in a PR chain.

Workflow

1. Identify Downstream Branches

gh pr list --state open --json number,title,headRefName,baseRefName --limit 50 | jq -r '.[] | "\(.baseRefName)\t\(.headRefName)"'

Build the dependency chain by finding PRs where baseRefName matches the current branch, then recursively find PRs based on those branches.

2. Merge and Push Each Branch

For each downstream branch in order:

git checkout <downstream-branch>
git merge <upstream-branch> --no-edit
git push origin <downstream-branch>

3. Handle Conflicts

If a merge conflict occurs:

1. Report the conflict to the user
2. Ask how to proceed (resolve manually, skip branch, or abort)

Example

Given this PR chain:

main
 └── feature-1
      └── feature-2
           └── feature-3

When feature-1 is updated, cascade merge will:

1. Merge feature-1 into feature-2, push
2. Merge feature-2 into feature-3, push

Output

Report results as a table:

Branch	Merged From	Status
feature-2	feature-1	Done
feature-3	feature-2	Done