This skill uses git-filter-repo from newren/git-filter-repo to perform controlled repository history rewrites. It is the right tool when an agent needs to remove secrets from old commits, strip large files, extract a subdirectory into its own module, rename tags during a split, or otherwise repair history before a repository is shared more widely. The upstream project positions it as the modern replacement for git filter-branch, with much better performance and far fewer ways to make a mess of the rewrite.

A user should invoke this skill when the task is a bounded repository surgery problem, not ordinary day-to-day Git use. If a secret landed in history, if a binary bloated the repo for months, or if a team wants to publish only one part of a monorepo, the agent needs a repeatable cleanup playbook. That is where this becomes a skill rather than a product listing. The agent inspects the damage, chooses flags such as --path, --invert-paths, --replace-text, --to-subdirectory-filter, or --analyze, runs the rewrite in a safe clone, and then documents the risky human follow-up, especially force-push coordination and fresh clones for collaborators.

The scope boundary is narrow and important. This is not a generic Git client, not a backup system, and not a repository browser. It is for history rewriting with explicit cleanup intent. Upstream documentation also spells out the prerequisites, including git >= 2.36.0 and python3 >= 3.6, plus the simple installation path of putting the git-filter-repo script on $PATH. That makes it a strong fit for security remediation, repo extraction, and pre-publication cleanup workflows.