Shopify Development with Cursor AI: A Step-by-Step Guide

Using AI agents to assist in coding is rapidly changing the development landscape. By leveraging Cursor—an AI-powered code editor—you can radically speed up your development workflow. This approach allows even those with low-to-no-code experience to safely modify Shopify theme files.

In this guide, we will cover how to set up a Git workflow with Shopify, configure Cursor, and use AI agents to build custom features.

1. Setting Up Your Git Workflow

The first step to a professional workflow is moving your theme files from Shopify to a local version control system. This allows you to sync changes safely.

Download Your Theme

1. Navigate to your Shopify Admin > Online Store > Themes.
2. Locate your live theme, click the ... (options) button, and select Download theme file.
3. Shopify will email you a ZIP file containing your theme code. Download and extract this to a local folder.

Create a GitHub Repository

1. Log in to GitHub and create a New Repository.
2. Name the repository (e.g., brand-theme-name).
3. Set visibility to Private.
4. Create the repository.

Push Local Files to GitHub

Open your terminal, navigate to the folder where you extracted your theme files, and run the following commands to initialize Git and push your code:

git init
git add .
git commit -m "Initial commit"
git branch -M main
git remote add origin https://github.com/YOUR_USERNAME/YOUR_REPO.git
git push -u origin main

2. Connecting GitHub to Shopify

Once your code is on GitHub, you need to link it back to your Shopify store to ensure continuous integration.

1. Return to your Shopify Admin > Online Store > Themes.
2. Click Add theme > Connect from GitHub.
3. Log in to your GitHub account and authorize Shopify.
4. Select the repository you just created and connect to the main branch.

Your theme is now synced. Any changes pushed to the main branch on GitHub will automatically update this theme on Shopify.

3. Setting Up the Local Development Environment

To edit code effectively, you need the Shopify CLI and the Cursor editor.

Install Shopify CLI

Ensure you have Node.js and npm installed. Run the installation command in your terminal:

npm install -g @shopify/cli @shopify/theme

Verify the installation by running shopify version.

Open in Cursor

Navigate to your project directory in the terminal and open it in Cursor:

cursor .

Recommended Extensions

To improve your developer experience, install the following extensions within Cursor:

• Shopify Liquid: Created by Shopify, this provides essential syntax highlighting and auto-completion.
• Liquid (by Frankie Laauo): Offers additional keyword auto-completion.

4. Running the Development Server

Before making changes, launch a local preview of your store. In your Cursor terminal, run:

shopify theme dev --store your-store-url.myshopify.com

• If prompted, log in to your Shopify account.
• Once running, press t to open the local preview in your browser.
• Press e to open the theme editor (customizer).

5. Coding with Cursor AI Agents

Cursor offers three main AI interaction modes:

1. Plan: Creates a massive checklist for complex tasks.
2. Ask: Chat with the AI about your codebase (great for research).
3. Agent: The AI actively writes and edits files in your project.

Example: Adding a Speed Setting to a Marquee

Let's walk through a real-world example. Suppose you have a marquee section that lacks a speed control setting. Instead of manually writing Liquid and JavaScript, use Cursor's Agent mode.

Step 1: Prompt the Agent Use natural language to describe the requirement:

"We have a section called marquee. Right now it has a setting for motion direction but no setting for controlling motion speed. How would we go about adding that?"

Step 2: Review and Implement The agent will analyze marquee.liquid and propose adding a range setting in the schema and updating the data attributes. Click Apply or Implement to let the AI write the code.

Step 3: Debugging AI Errors AI isn't perfect. In our example, the AI might add the schema setting but forget the unit property (e.g., "px" or "s"), causing a syntax error.

If the customizer doesn't update or the feature doesn't work:

1. Tell Cursor: "The setting exists, but it's not controlling the speed."
2. Cursor will re-analyze the JavaScript and Liquid files to apply the fix.
3. Always review the diffs. Check marquee.liquid, marquee.js, and any block files before accepting changes.

6. Finalizing Changes

Once the feature is working in your local preview:

1. Commit the changes:

   git add .
   git commit -m "Add speed setting to marquee"
   

2. Push to GitHub:

   git push origin main
   

Because we connected Shopify to GitHub in step 2, these changes will automatically deploy to your Shopify theme.

Conclusion

Using Large Language Models (LLMs) and agents like Cursor is the future of e-commerce development. While you still need to act as a supervisor to review the code, offloading the heavy lifting to AI allows you to build complex Shopify themes faster and more efficiently than ever before.