Merge Main

Merge Main

Fetch and merge the repository's base branch into the current feature branch.

Options

The user may provide these options inline:

• **--base `**: Override the auto-detected base branch (e.g., --base develop`)

Workflow

1. Pre-Flight Checks

Run these commands in parallel to understand the current state:

# Check for uncommitted changes
git status

# Detect the repository's default branch
gh repo view --json defaultBranchRef -q '.defaultBranchRef.name'

# Confirm which branch we are on
git branch --show-current

If --base was specified, use that value instead of the detected default branch.

If gh is not available, fall back to detecting the default branch with:

git remote show origin | grep 'HEAD branch' | sed 's/.*: //'

If the current branch is the default branch itself, warn the user that merging the base branch into itself is a no-op and stop.

2. Handle Uncommitted Changes

If git status shows uncommitted changes (staged or unstaged):

1. Warn the user that there are uncommitted changes.
2. Ask whether to:

• Stash: Run git stash before proceeding, then git stash pop after the merge completes.
• Commit first: Invoke the /commit skill, then continue with the merge.
• Abort: Stop without doing anything.

3. Fetch and Merge

git fetch origin 
git merge origin/

Where `` is the detected or overridden base branch name.

4. Handle Merge Result

Clean Merge

If the merge completes without conflicts:

1. Report success.
2. Show a summary of what was merged:

git log HEAD@{1}..HEAD --oneline

Already Up to Date

If git reports "Already up to date.", report that the branch is already current with the base branch and stop.

Conflicts

If the merge produces conflicts, proceed to the conflict resolution workflow below.

5. Conflict Resolution

When merge conflicts occur:

1. List conflicted files:

git diff --name-only --diff-filter=U

1. Resolve each conflicted file:

• Read the file and examine the conflict markers (>>>>>>).
• Use the surrounding code context, the intent of both sides, and the project's conventions to determine the correct resolution.
• For trivial conflicts (whitespace, import ordering, adjacent non-overlapping changes), resolve automatically.
• For non-trivial conflicts where the correct resolution is ambiguous, show the user both sides and ask which to keep or how to combine them.

1. Stage resolved files:

git add 

1. Complete the merge commit (GPG signed):

git commit -S --no-edit

This uses the default merge commit message generated by git. If the user wants a custom message, they can specify it.

6. Post-Merge Steps

After a successful merge (with or without conflict resolution):

1. Lockfile changes: If any lockfiles changed during the merge (e.g., package-lock.json, yarn.lock, pnpm-lock.yaml, go.sum, Gemfile.lock, poetry.lock, Cargo.lock, composer.lock), suggest running the appropriate install command:

• package-lock.json -> npm install
• yarn.lock -> yarn install
• pnpm-lock.yaml -> pnpm install
• go.sum -> go mod tidy
• Gemfile.lock -> bundle install
• poetry.lock -> poetry install
• Cargo.lock -> cargo build
• composer.lock -> composer install

1. Push:

git push

If the branch has no upstream, use:

git push -u origin HEAD

7. Stash Recovery

If changes were stashed in step 2, pop the stash after the merge completes:

git stash pop

If the stash pop produces conflicts, warn the user and list the conflicted files.

Error Handling

• On the default branch: Warn that merging the base branch into itself is a no-op and stop.
• No remote configured: Report the error and stop.
• Merge aborted by user: Clean up with git merge --abort.
• Fetch failure (network issues, authentication): Report the error clearly and stop.
• Stash pop conflicts: Warn the user and list conflicted files so they can resolve manually.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: cboone
• Source: cboone/agent-harness-plugins
• License: MIT
• Homepage: https://github.com/cboone/agent-harness-plugins

Install and usage instructions live in the source repository linked above.