--- title: Updating Stacks description: Amend, reorder, add, or remove commits in your stack. --- import GitGraph from '~/components/GitGraph.astro'; After pushing a stack, you'll need to make changes: responding to review feedback, adding commits, rearranging order, or squashing. This page covers every common scenario. In all cases, the workflow is the same: **make your changes locally, then run `mergify stack push`** to sync with GitHub. ## Amend the Latest Commit Make your changes, then amend: ```bash git add src/api/users.py git commit --amend ``` The Change-Id is preserved automatically. Then push: ```bash mergify stack push ``` Only the PR corresponding to the amended commit is updated. ## Edit a Commit Mid-Stack To modify a commit that isn't at the top of your branch, use interactive rebase. Stacks provides a shortcut: ```bash mergify stack edit ``` This opens `git rebase -i` from the fork point of your stack. You'll see your commits listed: ```text pick a1b2c3d feat: add user data model pick d4e5f6a feat: add user registration endpoint pick g7h8i9b test: add user registration tests ``` Change `pick` to `edit` for the commit you want to modify: ```text edit a1b2c3d feat: add user data model pick d4e5f6a feat: add user registration endpoint pick g7h8i9b test: add user registration tests ``` Save and close. Git pauses at that commit so you can make changes: ```bash # Make your changes git add src/models/user.py git commit --amend git rebase --continue ``` Then push: ```bash mergify stack push ``` ## Reorder Commits Open interactive rebase and change the line order: ```bash mergify stack edit ``` ```text pick d4e5f6a feat: add user registration endpoint pick a1b2c3d feat: add user data model pick g7h8i9b test: add user registration tests ``` Save and close. The PRs re-chain automatically when you push. :::caution Reordering can cause conflicts if later commits depend on earlier ones. Git will pause and ask you to resolve conflicts during the rebase. ::: ## Add a Commit Just commit normally anywhere in your branch: ```bash git add src/api/auth.py git commit -m "feat: add authentication middleware" ``` On the next `mergify stack push`, a new PR is created and inserted at the correct position in the chain. ## Remove a Commit Open interactive rebase and change `pick` to `drop` (or delete the line): ```bash mergify stack edit ``` ```text pick a1b2c3d feat: add user data model drop d4e5f6a feat: add user registration endpoint pick g7h8i9b test: add user registration tests ``` On push, the orphan remote branch is deleted and the remaining PRs re-chain. ## Squash Commits To combine two commits into one, use `squash` or `fixup` in interactive rebase: ```bash mergify stack edit ``` ```text pick a1b2c3d feat: add user data model squash d4e5f6a feat: add user registration endpoint pick g7h8i9b test: add user registration tests ``` The surviving commit keeps its Change-Id, so the corresponding PR is updated. The absorbed commit's remote branch is cleaned up automatically. ## After a PR Merges When the bottom PR in your stack merges into `main`, the next PR's base automatically updates to `main`. To keep your local branch in sync, just push again: ```bash mergify stack push ``` Before the merge, your stack looks like this: After PR #1 merges, commit A lands on `main`. The remaining PRs re-chain: Stacks rebases on `main` automatically, detects that the merged commit is already in `main`, and skips it. The remaining PRs update as needed.