Sweep, from Sweep AI, Inc., is an AI coding assistant. Its documentation describes it as an AI junior developer that turns bug reports and feature requests into code changes, installed on chosen repositories as a GitHub app (a bot account with permissions on those repositories).
A developer creates a GitHub issue whose title starts with "Sweep:", or adds the Sweep label to an existing issue. Sweep reads the codebase, plans the changes and writes a pull request: a proposed set of code changes for the team to review and merge. It then runs the repository's GitHub Actions and keeps working until the CI (continuous integration) checks pass. A comment that starts with "Sweep:" on its pull request asks it to change the code. The documentation lists limits: repositories of more than about 5,000 files, refactors of more than 5 files or 300 lines, and images.
The source code is public on GitHub under the Sweep Enterprise Edition license: free for personal, non-commercial use, while production or commercial use needs a paid Sweep subscription. The repository's README says the team now builds an AI coding assistant for JetBrains IDEs.