# Monitored branches and incremental scans

> Rescan a branch when it changes, and re-analyse only what changed since the last scan.

Source: https://scansuite.eu/documentation/usage/static-code-analysis/scheduling-periodic-and-incremental-scans
Last reviewed: 2026-10-19

Two Scanning Modes on the Static Analysis page re-analyse only what changed: **Monitor Changes** watches a branch and scans each change as it lands, and **Incremental Scan** scans the changes since the last scan once, when you ask. Both keep the cost of a re-scan proportional to the change rather than to the size of the codebase.

Daily, Weekly and Monthly schedules, and managing every schedule and monitor, are covered in [Schedule the scan](https://scansuite.eu/documentation/usage/schedule-the-scan).

> **Note:** Both modes need a Git repository. The form disables them while a ZIP archive is the source, because an archive cannot be fetched again.

## Before you start

| Prerequisite | How to check |
|---|---|
| The repository is entered on the Git Repository tab | One repository for Monitor Changes; Incremental Scan takes several. |
| SSH repositories: the team has an SSH key | Monitor Changes always clones with the team SSH key, even when you have your own. Teams → Scanning tab → Team SSH key shows Saved. See [Git repository authentication](https://scansuite.eu/documentation/usage/static-code-analysis/git-repository-authentication). |
| A language for native engines | With Main Language set to All supported languages, these modes run no native language engine. Choose the language if you need its engine. |

## Watch a branch

1. **Open Static Code Analysis and the Git Repository tab**

   Enter one repository in Repositories, and the branch in Branch Name (empty means the default branch).
2. **Set Scanning Mode to Monitor Changes**

   Under Watch the repository.
3. **Choose the Product Assignment and the scanners**
4. **Click Start Analysis**

   The branch is scanned now, then checked every hour.

**Check it worked:** the first scan opens its scan page, and the monitor is listed on the **Schedules** page. If the form says *Schedules and repository watches clone with the team SSH key, and none is set*, a team admin or operator sets the team key first.

![Repository monitoring configuration](https://scansuite.eu/static/assets/img/docs/usage/static-code-analysis/scheduling-periodic-and-incremental-scans/02.png)

*Configuring repository monitoring*

### What a monitored run scans

- Every hour the branch is checked for new commits. If nothing changed, no scan is started.
- If the branch moved, only the added, modified or renamed files are analysed by AI Native SAST, Quick, Full, Custom Rules and IaCS Analysis.
- Secrets Detection, Dependency Check and the native language engine still scan the whole checkout. With *All supported languages*, no native language engine runs.
- When the change cannot be worked out (the earlier commit is gone, the history was rewritten, or the change only deletes files) the run scans everything.

## Scan only what changed, once

1. **Open Static Code Analysis and the Git Repository tab**

   Enter one or more repositories.
2. **Set Scanning Mode to Incremental Scan**

   Under Run now.
3. **Keep the product, Main Language and scanners of the scan you compare with**

   See below.
4. **Click Start Analysis**

**Check it worked:** the scan page opens, or, when there are no new commits, the form says *Nothing to scan* and no scan is started. The first Incremental Scan of a branch scans everything.

## What the change is measured against

An Incremental Scan or a new monitor compares the branch with the last successful Full scan or scheduled scan of the same repository, branch, product, Main Language and scanner settings. If there is none, it scans everything. Setting up monitoring on a repository you have already scanned therefore does not re-scan the whole tree. Custom Scope, Verify Fixes and archive scans never serve as the comparison point.

> **Tip:** Change the product, language or scanners and the next incremental run scans everything again, because no earlier scan matches. Keep these settings stable for the branches you watch.

## Managing monitors

Every monitor is listed on the **Schedules** page, where you run it now, pause, resume, rename or delete it; see [Schedule the scan](https://scansuite.eu/documentation/usage/schedule-the-scan). To change what a monitor scans, choose it in **Saved Scans** on the Static Analysis page, change the form and click **Start Analysis**.