Docs

Getting started

From install to a merged theme in the store. About ten minutes the first time.

1. Install

Open ThemeMerge on the Shopify App Store, click Install and pick the store. Shopify asks you to approve two scopes:

read_themes to read the live theme, the working copy and their files.
write_themes to write merged results into a theme you choose. This only works once the theme-write exemption is granted.

ThemeMerge has no access to customers, orders or products.

2. Record a baseline

The baseline is a snapshot of the live theme at the moment the working copy is made. Do this before you start the redesign.

Open Compare themes → Baselines for future merges.
Choose Duplicate + record baseline. ThemeMerge duplicates the live theme and snapshots it in the same step.

Already duplicated it yourself?

Pick the copy under I just duplicated it myself and click Record baseline. This is only correct if nobody has edited the live theme since the copy was made.

3. Run the first compare

In Compare themes, set Live theme to the published theme and Working copy to your redesign.
Leave Baseline on Automatic. It uses the snapshot recorded when the copy was made.
Click Compare. You get every changed file, classified as changed on live, changed in copy, auto-merged or conflict.

4. Decide conflicts

Open each file marked Conflict. For theme-editor JSON you see each key changed on both sides with its original value. For code you see hunks side by side.

Per conflict: Live or Copy for a key, or Live, Copy, Both (live first), Both (copy first) for a hunk.
Per file: keep the working copy version, take the live version, use the merged result, or delete the file.
By hand: edit the merged result directly in the Result tab.

5. Export and upload

When Need a decision reaches 0, click Download full theme (Pro). On Free, use the CLI path below.
In the Shopify admin go to Online Store → Themes → Add theme → Upload zip file and choose the zip.
Shopify creates a new unpublished theme. Preview it, then publish it when the client signs off.

6. Push with Shopify CLI

Prefer the CLI? Click Download changed files. The zip holds only the files that differ plus a MERGE-REPORT.md with the exact push command. Pull the working copy, drop the files in, and push only those files:

shell

shopify theme pull --store your-store.myshopify.com --theme 944 --path ./redesign
unzip -o thememerge-m_4kz19-changed.zip -d ./redesign
cd redesign

from MERGE-REPORT.md

shopify theme push --store your-store.myshopify.com --theme 944 \
  --only templates/index.json \
  --only assets/base.css \
  --only config/settings_data.json \
  --only layout/theme.liquid \
  --only sections/countdown-timer.liquid

To push the result as a brand-new theme instead of into the working copy, push the whole folder with --unpublished:

shell

shopify theme push --store your-store.myshopify.com --unpublished

7. Apply in the app

Once the theme-write exemption is granted, two more buttons turn on.

Create merged theme duplicates the working copy and writes the merged result into the duplicate, leaving the original untouched.
Apply to working copy snapshots the copy, then writes the merged result into it.

Both write only files that differ. Neither writes the live theme.