Version Control
===============

Qubit-Pro includes custom version control to help you save snapshots of your designs, compare layouts, and roll back changes.

Saving a Layout Snapshot
------------------------

To save the current state of your chip design:

1. Open the **Version Control** page.
2. In the snapshot form, fill in the details:
   * **Tag**: Type a version number or tag (for example, *v1.0* or *v1.1-testing*).
   * **Commit Message**: Write a short description explaining what you changed (for example, *Optimized resonator spacing on Q1*).
3. Click the **Save Snapshot** button.

*What you just did:* You saved a permanent, read-only snapshot of the current layout to the project database. It will appear on your version timeline.

Comparing Layout Differences (Diff)
-----------------------------------

1. Go to the version **Timeline** on the Version Control page.
2. Select two different snapshots from the list.
3. Click the **Diff** or **Compare** button.
4. The system will display the differences between the two versions, highlighting added, modified, or removed components and parameter changes.

*What this means:* Comparing differences helps you track exactly how a design has evolved and identify which modifications improved or degraded the simulated performance.

Restoring an Older Version
--------------------------

If you want to discard recent changes and go back to an older layout:

1. Find the desired snapshot in the version **Timeline**.
2. Click the **Restore** or **Rollback** button.
3. Confirm the action when prompted.

*What you just did:* You set the active design back to the selected snapshot. Any modifications made after that snapshot will be overwritten by the restored version.

Downloading a Snapshot
----------------------

1. Select any snapshot on the version timeline.
2. Click the **Download** button.
3. The layout definition file will download as a JSON file to your local computer.

*What this means:* You can archive your design files locally or import them into other offline tools.