| name | generating-patches |
| description | Generates git patch files from codebase modifications for local application. Use when user mentions patch, diff, export changes, bring changes back, apply locally, or after editing uploaded codebases. |
Generating Patches
Generate portable git patch files from codebase modifications, enabling users to apply Claude's edits to their local repositories.
When to Use
Activate after modifying files in an uploaded codebase when the user needs to transfer changes back to their local environment. Typical workflow: user uploads zip → Claude edits files → this skill exports changes as a patch.
Prerequisites
Verify git is available and the working directory is a git repository (or can be initialized as one):
git status 2>/dev/null || git init
If working with an uploaded codebase that lacks git history, initialize and create a baseline commit before making edits:
git init
git add -A
git commit -m "Baseline: original uploaded state"
Generating the Patch
After completing edits, generate a unified diff:
git diff > /mnt/user-data/outputs/changes.patch
git diff --cached > /mnt/user-data/outputs/changes.patch
git diff HEAD > /mnt/user-data/outputs/changes.patch
For committed changes (preserves commit messages and metadata):
git format-patch --stdout baseline..HEAD > /mnt/user-data/outputs/changes.patch
git format-patch --stdout -n 3 > /mnt/user-data/outputs/changes.patch
Handling Edge Cases
Binary files: Git diff excludes binaries by default. Warn the user if binary files were modified:
git diff --name-only --diff-filter=M | xargs file | grep -v "ASCII\|UTF-8\|empty"
Large patches: For extensive changes, consider splitting by directory or file type:
git diff -- "*.py" > /mnt/user-data/outputs/python-changes.patch
git diff -- src/ > /mnt/user-data/outputs/src-changes.patch
No changes detected: Verify files were actually modified. Common issues:
- Edits made to copies outside the git tree
- Files not tracked by git (need
git add first)
Output Requirements
Always output to /mnt/user-data/outputs/ with a descriptive filename. Provide the download link:
[Download changes.patch](computer:///mnt/user-data/outputs/changes.patch)
User Instructions
Include these instructions with every patch delivery:
To apply this patch locally:
cd /path/to/your/repo
git apply --check changes.patch
git apply changes.patch
If using format-patch output (includes commit metadata):
git am changes.patch
Troubleshooting:
git apply --reject changes.patch — applies what it can, writes .rej files for conflictsgit apply -R changes.patch — reverses a previously applied patchgit apply --3way changes.patch — enables three-way merge for conflicts
Optional: PR Description
When requested, generate a pull request description from the patch:
echo "## Summary"
git diff --stat
echo ""
echo "## Changes"
git diff --name-only | while read f; do echo "- \`$f\`"; done
Combine with a brief description of what was changed and why, suitable for GitHub PR body.
