Git Diff Summarizer

What this skill does

Reads a raw git diff or unified diff text and returns a structured breakdown of what changed. Identifies the affected files, counts added and removed lines per file, writes a human-readable English summary of the change intent, and suggests a conventional commit message (feat:, fix:, chore:, refactor:, docs:) based on the change type detected.

Inputs

• diff_text — raw output of git diff, git diff HEAD, or a .patch file content
• context — optional string describing the purpose of the change (improves commit message quality)

Outputs

• files_changed — list of {path, additions, deletions, change_type} objects
• lines_added — total lines added across all files
• lines_removed — total lines removed across all files
• summary — 2–3 sentence plain-English description of what the diff does
• commit_message — suggested conventional commit message, e.g. fix: correct token expiry check in auth middleware

Example

git diff HEAD | asf query "summarize this diff and suggest a commit message"

Output:

{
  "files_changed": [
    {"path": "src/auth.js", "additions": 4, "deletions": 2, "change_type": "modified"}
  ],
  "lines_added": 4,
  "lines_removed": 2,
  "summary": "Fixed token expiry comparison using strict inequality. Updated unit test to cover the edge case.",
  "commit_message": "fix: use strict inequality for token expiry check in auth middleware"
}

Source & license

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

• Author: theshubh007
• Source: theshubh007/agent-skill-finder
• License: MIT

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