Plannotator is a free, open-source review tool for AI coding agents, including Claude Code, OpenCode, Codex, Pi, and Droid. It helps developers stay in control of agent-generated plans and code by providing a dedicated workspace for review rather than relying on terminal text alone. Before a plan is executed, users can comment on specific sections, mark scope for deletion, or suggest replacement text. For code, Plannotator offers a diff viewer with side-by-side or unified layouts, file navigation, line-level annotations, code suggestions, and options to stage or unstage changes.

Feedback is sent back to the agent as structured instructions, avoiding manual copying and retyping. The tool runs locally, keeps review data local by default, and states that it does not use analytics or usage telemetry. Additional features include saved plan revisions with diffs, automatic draft recovery, and link sharing. Integrations include VS Code, Obsidian, Bear, and GitHub pull requests. Plannotator is available through installation and agent-specific commands, with a hosted team workspace planned separately; the local plugin remains free and open source.