Plannotator - Annotate Anything

Product Introduction

1. Definition: Plannotator is an open-source, local-first visual annotation and review framework designed specifically for AI coding agents and LLM-driven development workflows. It functions as a specialized interface layer that intercepts AI-generated plans and code diffs, providing a graphical environment for human-in-the-loop (HITL) verification and refinement.

2. Core Value Proposition: Plannotator addresses the "black box" problem of autonomous AI agents by allowing developers to visually mark up, edit, and approve agent plans before execution. By integrating structured feedback loops directly into tools like Claude Code and Copilot CLI, it maximizes the accuracy of AI code generation, ensures data privacy through local execution, and streamlines the collaborative review of AI-proposed architectural changes.

Main Features

1. Interactive Plan & Code Review UI: Plannotator launches a local browser-based interface whenever an integrated AI agent proposes a plan. Users can perform granular edits—including deletions, insertions, and replacements—using a visual editor. This feedback is then converted into structured data and injected back into the agent's context, allowing the model to self-correct based on precise human intent rather than vague chat prompts.

2. Comprehensive Annotation Commands (/plannotator-annotate & /plannotator-last): The tool provides a robust CLI and slash-command suite. Users can run /plannotator-annotate followed by a file path, URL, folder, or markdown document to ingest and mark up external data. The /plannotator-last command specifically targets the most recent agent response, enabling immediate correction of hallucinations or logic errors in the agent's output.

3. Zero-Knowledge Private Sharing: For team collaboration, Plannotator includes an end-to-end encrypted (E2EE) sharing mechanism. Small plans are stored entirely within the URL hash (no server storage), while larger plans are encrypted using AES-256-GCM in the browser before being uploaded to a short-link service. The server never sees the plaintext, as the decryption key resides only in the shared URL.

4. Multi-Agent Ecosystem Integration: The tool features native hooks for a wide array of AI development environments, including Claude Code, GitHub Copilot CLI, Gemini CLI, OpenCode, Pi, and Codex. It supports specialized workflows like "Plan Mode" in Gemini and "Plugin Marketplace" installations in Claude, ensuring that the annotation UI feels like a native extension of the developer's chosen AI stack.

Problems Solved

1. Pain Point: Lack of granular control over autonomous agents. Developers often face an "all-or-nothing" choice when an agent proposes a 10-step plan. Plannotator solves the difficulty of steering agents by allowing users to surgically edit specific steps within a complex plan without restarting the entire prompt session.

2. Target Audience: Software Engineers using AI coding assistants, DevOps professionals managing automated infrastructure scripts, Technical Architects reviewing AI-generated system designs, and Knowledge Management enthusiasts (specifically Obsidian users) building personal "LLM Wikis."

3. Use Cases:

• Refining multi-file refactoring plans proposed by Claude Code to ensure edge cases are handled.
• Performing visual code reviews on GitHub Pull Requests with AI-augmented insights.
• Annotating long-form technical documentation or web content to extract structured feedback for an integrated agent.
• Collaborative debugging where one developer annotates a plan and shares the encrypted link with a teammate for secondary review.

Unique Advantages

1. Differentiation: Unlike cloud-based AI platforms that store prompt history on central servers, Plannotator is local-first and private. While traditional code review tools are built for human-to-human interaction, Plannotator is purpose-built for human-to-agent interaction, focusing on "Structured Feedback" that LLMs can programmatically ingest.

2. Key Innovation: The primary innovation is the seamless bridging of the Command Line Interface (CLI) and the Graphical User Interface (GUI). It allows developers to stay in their terminal for the heavy lifting while instantly "popping out" to a visual UI for complex spatial tasks like plan editing and diff comparison, which are inherently difficult to manage in a text-only terminal.

Frequently Asked Questions (FAQ)

1. Is Plannotator private and secure for enterprise use? Yes. Plannotator runs locally on your machine. All annotations and feedback stay on your local system unless you explicitly use the sharing feature. Even when sharing, data is protected by AES-256-GCM end-to-end encryption, meaning the hosting server has zero knowledge of your code or plans.

2. Which AI agents are compatible with Plannotator's visual review? Plannotator supports a broad range of industry-leading agents including Claude Code, GitHub Copilot CLI, Gemini CLI, OpenCode, Pi, and Codex. It integrates via plugins or shell hooks, allowing it to trigger automatically whenever the agent enters a planning or diff-generation phase.

3. Can I use Plannotator to build a personal knowledge base or LLM Wiki? Absolutely. Many users utilize the /plannotator-annotate command to ingest URLs, books, and markdown files. This allows you to visually highlight and annotate key information which is then fed into your agent, making it an ideal tool for creating high-fidelity local documentation and "LLM Wikis" in tools like Obsidian.