MergeAtlas

MergeAtlas is an open-source (MIT) agent skill that turns a pull request into an interactive map served on localhost, so reviewers start from what a change is for and what it reaches before reading individual lines. It runs inside agents such as Claude Code or Codex and builds its analysis from the issue, the diff and the surrounding source.

What It Is

MergeAtlas is a code review comprehension tool delivered as an agent skill. From inside a pull request's repository, you ask your agent to map the PR, and the map opens at a local address. It is aimed at changes that reach past their diff, such as those spanning several files, some affected only indirectly. It stops at understanding: it does not hunt for bugs or approve changes for you.

How the Map Works

The map opens with context: how that part of the project works today, the problem, and what the pull request does about it. Changed files sit in groups that change for the same reason, and arrows run from each cause to its effect, including into unchanged files that behave differently because of the change. Tests stack beside the cards they verify, and whitespace, formatting, renames and generated files are set apart with a reason each. Claims link back to the lines they come from.

Review Workflow

A tree view offers a collapsible outline with keyboard navigation, and cards can switch between compact and detailed modes. Files can be marked as reviewed, with a progress bar and previous/next stepping. Pressing Cmd/Ctrl+K jumps to a file by name, and a map can be exported as a single shareable HTML file. Before publishing, each card is handed to a fresh subagent to find what it leaves unexplained; the model for this step is configurable.

Setup and Tickets

It requires an agent that runs skills, Python 3, git and the GitHub CLI signed in. Installation is via a Claude Code plugin marketplace, skills.sh (npx skills add) or a manual symlink. Linked GitHub issues work out of the box; for other trackers (Jira, Linear, Trello, Asana, Shortcut, ClickUp, Azure Boards) the agent reads the ticket through its existing connection, and MergeAtlas stores no tracker credentials. Maps and working files stay on your machine.