<?xml version="1.0" encoding="utf-8"?> <![CDATA[How to Use AI with zapgpt to Generate Git Commit Messages from a Git Diff]]> <![CDATA[/2026/09/14/2026-09-14-zapgpt_git_commit_message/]]> 1789324200 <![CDATA[How to Use AI with zapgpt to Generate Git Commit Messages from a Git Diff Writing useful Git commit messages can be surprisingly time-consuming, especially when a change touches multiple files. With zapgpt, you can export your repository&rsquo;s diff and provide it to an AI model to generate a concise, meaningful commit message. This workflow is simple: Generate a Git diff. Save the diff to a file. Pass the file to zapgpt. Ask the selected AI model to write a commit message. Generate a Git Diff From the root of your Git repository, run: 1 git diff &gt; git-diff.txt This compares your working tree with the index and saves the output to git-diff.txt. To include staged changes instead, use: 1 git diff --cached &gt; git-diff.txt To include both staged and unstaged changes, generate the diff against HEAD: 1 git diff HEAD &gt; git-diff.txt The resulting file contains the exact code changes that you can provide to the AI model. Generate a Commit Message with zapgpt Pass the diff file to zapgpt with the model and provider you want to use: 1 2 zapgpt -m &lt;model&gt; -p &lt;provider&gt; -f git-diff.txt \ &#34;Write a concise Git commit message for this diff.&#34; Replace the placeholders with your preferred model and provider. For example: 1 2 zapgpt -m gpt-4o -p openai -f git-diff.txt \ &#34;Write a concise Git commit message for this diff.&#34; The -f option supplies the contents of git-diff.txt to the prompt. The model can then analyze the changed files and produce a message based on the actual implementation. Use a More Precise Prompt The prompt in the command should request a commit message rather than another diff. A stronger prompt can enforce a consistent format: 1 2 zapgpt -m &lt;model&gt; -p &lt;provider&gt; -f git-diff.txt \ &#34;Generate one concise Git commit message from this diff. Use Conventional Commits format. Return only the commit message.&#34; A generated result might look like: 1 feat(auth): add refresh token rotation You can also request additional context when needed: 1 2 3 4 5 zapgpt -m &lt;model&gt; -p &lt;provider&gt; -f git-diff.txt \ &#34;Analyze this Git diff and return: 1. One Conventional Commits message 2. A short explanation of the change 3. Any potential breaking changes&#34; For automation, ask the model to return only the message. This makes the output easier to copy directly into Git. Generate a Commit Message for Staged Changes A common workflow is to stage changes first, inspect them, and then ask the AI to write the commit message: 1 2 3 4 5 git add . git diff --cached &gt; git-diff.txt zapgpt -m &lt;model&gt; -p &lt;provider&gt; -f git-diff.txt \ &#34;Write one concise Conventional Commit message for these staged changes. Return only the message.&#34; After reviewing the generated message, use it with Git: 1 git commit -m &#34;feat(auth): add refresh token rotation&#34; Do not commit the AI-generated message blindly. Review the diff and confirm that the message accurately describes the changes. Create a Reusable Shell Function If you use this workflow frequently, create a shell function: 1 2 3 4 5 6 7 8 ai_commit_message() { git diff --cached &gt; /tmp/git-diff.txt zapgpt -m &#34;${1:-gpt-4o}&#34; \ -p &#34;${2:-openai}&#34; \ -f /tmp/git-diff.txt \ &#34;Write one concise Conventional Commit message for these staged changes. Return only the commit message.&#34; } Run it like this: 1 ai_commit_message gpt-4o openai If your shell supports command substitution, you can use the generated output directly: 1 2 git commit -m &#34;$(zapgpt -m gpt-4o -p openai -f /tmp/git-diff.txt \ &#39;Write one concise Conventional Commit message for these staged changes. Return only the commit message.&#39;)&#34; Review the output before committing, especially when the diff contains complex or security-sensitive changes. Protect Sensitive Repository Data A Git diff can contain more than source code. It may include: API keys accidentally added to a file Internal URLs and hostnames Credentials or tokens Customer information Proprietary implementation details Comments containing sensitive operational data Before sending a diff to an external AI provider, inspect it: 1 less git-diff.txt You can also search for common secret patterns: 1 grep -Ein &#34;api[_-]?key|secret|token|password|private[_-]?key&#34; git-diff.txt Remove sensitive data from the diff or use an approved self-hosted or enterprise AI provider when repository confidentiality matters. Ideally ensure that you do not commit that information to repo as well :). Recommended End-to-End Workflow Use this compact workflow for staged changes: 1 2 3 4 5 6 7 8 git add . git diff --cached &gt; git-diff.txt zapgpt -m &lt;model&gt; -p &lt;provider&gt; -f git-diff.txt \ &#34;Generate one concise Conventional Commit message for this diff. \ Return only the commit message.&#34; rm git-diff.txt Conclusion Using zapgpt with a Git diff provides a fast way to generate consistent commit messages without manually summarizing every changed file. The basic workflow is: 1 2 3 git diff --cached &gt; git-diff.txt zapgpt -m &lt;model&gt; -p &lt;provider&gt; -f git-diff.txt \ &#34;Write one concise Conventional Commit message for this diff.&#34; For the best results, generate the diff from staged changes, use a precise prompt, review the model&rsquo;s output, and check the diff for secrets before sending it to an AI provider. ]]>