Branch Compare in Develop Mode

Branch Compare helps you understand what differs between two branches before deciding what to review, test, or change. Select repositories and branches, start a background comparison, then read the coding agent’s report alongside the exact commits it inspected.

Review without changing code

Branch Compare is read-only. It inspects Git data in an isolated temporary repository and does not change source files, create commits, push branches, or merge anything. Use Run Task separately when you want to implement a change.

Where it fits in Develop

After connecting a project, the Develop sidebar follows this order: Project Overview → Code Query → Branch Compare → Run Task → Prompt Engineer.

• Project Overview gives you the wider codebase context.
• Code Query answers questions about the code.
• Branch Compare reviews differences between selected branches.
• Run Task plans and executes changes you approve.
• Prompt Engineer helps refine a request before you submit it to Run Task.

Start with the Develop Mode tutorial if you have not connected a repository yet. Branch Compare is on by default. If it is not shown in your sidebar, it has been turned off for your account: see feature availability or contact support. On a project shared with you, these steps follow the project owner’s account.

Choose repositories and branches

1. Switch to Develop, select your project, and open Branch Compare.
2. Under Choose repositories and branches, tick the checkbox for each repository you want to include. Select 1–10 repositories; each must have ready status.
3. For each selected repository, choose a Reference branch and a Compare branch from its dropdowns:
   • Reference is the starting point for the comparison, such as main.
   • Compare is the branch whose differences you want to understand, such as feature/billing-update.
4. Check every selected row. Branch choices are independent for each repository: your frontend and backend do not need matching branch names.
5. Click Run comparison.

For example, compare the frontend’s main with feature/checkout-ui and the backend’s main with feature/checkout-api in the same run. Leave unrelated repositories unchecked.

Only remote branches appear in the dropdowns. A branch that exists only on your computer will not be listed. If a branch list fails to load, use Retry branches on that repository; other rows can still load independently.

Follow the background comparison

The comparison runs asynchronously and appears in History. Repository selection and branch controls are locked while a comparison is active.

Status	Meaning
pending	The comparison has been accepted and is waiting to start
running	The selected branches are being inspected
completed	The comparison finished; open its report
failed	At least one repository or the overall comparison failed; inspect the errors and any available report

You can leave the view and return later, or reload the page. History is saved with the project, and pending comparisons reconnect when you return. Use Refresh history if results are not updating or a refresh error appears. A monitoring interruption does not by itself mean that the background comparison failed.

Read the report

Select a History entry to open its Comparison report. History is shown newest first. Each entry shows its repositories, creation date, and status.

The report includes:

• Created, Started, and Completed dates and times, when available, with a local timezone rather than relative labels such as “yesterday”.
• The Reference and Compare branch names for each repository, its status, and any repository-specific error.
• The exact commit SHAs resolved for the comparison. These are displayed as 12-character abbreviations: hover to see the full SHA or click to copy it. Not resolved yet means a commit identifier is not available.
• A Markdown analysis from the coding agent, explaining behavioural changes, compatibility concerns, risks, and recommended testing based on the evidence it inspected.

Branch names can move; saved snapshots do not

Branches resolve to exact commits when the job runs, not when you select them or click Run comparison. A commit pushed while the comparison is waiting can therefore be included.

Once resolved, the saved SHAs identify the immutable snapshots used for that report. Later commits, branch movement, or another comparison do not rewrite the old report to describe newer code. Run a new comparison to review updated branches, and use the dates and full SHAs to distinguish runs.

Understand the scope

Branch Compare examines the direct difference between the two branch-tip file trees: the files as they exist at the resolved Reference and Compare commits. It is not a merge-base comparison of only the commits introduced by a feature branch, and it does not simulate merging that branch. If both branches have diverged, the report can include differences from changes on either side.

The coding agent chooses which evidence to inspect, including changed-file lists, patches, commit history, and relevant file contents. This is agent-selected coverage, not an exhaustive audit of every file or possible interaction. Uninspected evidence is unknown, not proof that an area is unchanged or safe. Read any evidence gaps, truncation notices, and binary-file limitations in the report.

Recommendations are not test results

Branch Compare does not run project tests or builds. Suggested tests are next steps, not evidence that the code passes them. A completed report is not approval to merge and does not guarantee compatibility or the absence of defects.

Handle errors without losing context

• Repository not ready: finish repository setup before selecting it.
• Branches unavailable: use Retry branches and check that the repository is accessible and the branches still exist remotely. See Git credentials if repository access needs attention.
• History or report refresh error: click Refresh history to reload saved results before starting another comparison.
• Failed comparison: open its History entry and inspect both the overall error and each repository’s status. Successful repository reports and resolved SHAs can remain useful even if another repository failed. An overall failed status does not mean every repository failed.
• No Markdown report available: use the displayed status and errors to understand what finished; do not treat an absent report as “no differences”.

After addressing the problem, start a new comparison. Keep the older entry as context for the failure and the commits it reached. For persistent problems, contact support with the displayed dates, repository statuses, and error details—never include credentials.

Turn findings into next steps

Use Code Query in Develop Mode to investigate a finding further. Include the relevant paths and commit SHAs so the question is clear; Code Query is a separate conversation, not an automatic continuation of the comparison.

For fixes or additional tests, write a scoped request in Run Task and review the Task Plan before execution. Prompt Engineer can help you refine that request. Include the report’s recommendations and identify the branches or commits you reviewed rather than assuming another agent automatically receives the report.