CopyCat is a VS Code extension that helps you share code with large language models (LLMs) by packaging selected files into a single, well-formatted text block. Perfect for when you need to provide context to AI assistants like ChatGPT, Claude, or GitHub Copilot.
Simply use the CopyCat section in the Explorer panel to select files and folders, then click/keybind to copy them to your clipboard (with additional options for user prompts, system prompts, and file tree modes).
Oh, and it automatically respects .gitignore rules and includes a comprehensive default ignore list for common file types that aren't useful for LLM context.
✨ Features
Visual File Selection: Browse and select files through an intuitive tree view in the Explorer
Token Estimation: See approximate token counts for each file to manage context window limits
Smart Ignoring: Automatically respects .gitignore rules and includes a comprehensive default ignore list for common file types that aren't useful for LLM context
Flexible File Tree Modes: Choose how much file structure to include:
Full Tree: Complete project structure (default)
Relevant Tree: Only selected files and their parent directories
No Tree: Just the file contents without structure
Multiple Copy Modes:
Copy files with basic formatting
Copy files with a custom prompt for better LLM context
Language Detection: Automatic syntax highlighting for 20+ programming languages
Real-time Updates: File tree updates automatically as you modify your codebase
🚀 Quick Start
Install the Extension: Search for "CopyCat" in the VS Code Extensions marketplace and install it
Open Your Project: Open a folder/workspace in VS Code
Access CopyCat: Look for the "CopyCat" section in the Explorer panel (usually on the left)
Select Files: Check the files or folders you want to include in your LLM conversation
Choose File Tree Mode: Use the tree icon in the toolbar to cycle through tree modes
Copy to Clipboard: Click the clipboard icon or use the command palette to copy your selection
Paste in LLM: Paste the formatted output into your AI assistant
📋 How to Use
Basic Usage
In the CopyCat view (in the Explorer panel), you'll see your project's file structure
Check the boxes next to files or folders you want to include
The total token count is shown at the top of the view
Click the clipboard icon 📋 to copy all selected files to your clipboard
Paste the result into your LLM conversation
File Tree Modes
CopyCat offers three different ways to include file structure:
🌳 Full Tree (default): Shows the complete project structure - great for small projects or when you want full context
📁 Relevant Tree: Shows only the selected files and their parent directories - perfect for large projects to reduce noise
📄 No Tree: Excludes file structure entirely - ideal for quick code snippets
Toggle between modes using the tree icon in the CopyCat toolbar, or configure it in settings.
Advanced Usage with Prompts
Select your files as usual
Click the comment icon 💬 (or use Command Palette → "CopyCat: Copy Selected Files to Clipboard with Prompt")
Enter a description of what you want the LLM to help you with
The extension will format your request along with the selected files
Copy and paste into your LLM
Command Palette Commands
CopyCat: Copy Selected Files to Clipboard - Basic copy with file contents
CopyCat: Copy Selected Files to Clipboard with Prompt - Copy with custom prompt
CopyCat: Toggle File Tree Mode - Cycle through tree modes
CopyCat: Set File Tree Mode - Choose specific tree mode
Debug CopyCat Settings - View current settings and statistics
📄 Output Format
When you copy files, they're formatted as clean markdown with:
Codebase Overview - Brief introduction for the LLM
File Structure - Project tree (based on your selected mode)
Selected Files - Full contents of your chosen files with proper syntax highlighting
Prompts (optional) - System/user prompts that get added to the context so you can simply paste and go
⚙️ Settings
Configure CopyCat in VS Code settings:
File Tree Mode: Choose between "full", "relevant", or "none" for file structure inclusion
Show Ignored Nodes: When enabled, files matching ignore patterns appear greyed out but unselectable. When disabled (default), they're completely hidden.
System Prompt: Add a custom system prompt that gets prepended to every "Copy with Prompt" request.
Default Ignore Patterns: Customize the list of file patterns that are automatically ignored. These patterns are applied in addition to .gitignore and .contextignore rules. The default list includes common file types that aren't useful for LLM context like images, videos, data files, build artifacts, and dependencies.
📁 Ignore Files
CopyCat respects multiple ignore mechanisms (in order of precedence):
Default Ignore Patterns: Built-in patterns for common file types (configurable in settings)
.gitignore: Will ignore files that are ignored by git
.contextignore: Project-specific ignore rules for LLM context (create this file in your project root)
Create a .contextignore file in your project root to specify additional files or patterns that should be excluded from LLM context, using the same syntax as .gitignore.
🤝 Contributing
Found a bug or have a feature request? Visit our GitHub repository to contribute or report issues.
