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Roo Code - Open-Source AI for VS Code

Updated: October 10, 2025

Open-source VS Code extension for agentic coding. Customizable modes, conservative edits, and complete control over AI behavior.

Roo Code - Open-Source AI for VS Code

Roo Code is an open-source VS Code extension that brings agentic AI coding to your editor. With customizable modes and a focus on minimal, maintainable changes, Roo gives you complete control over AI assistance.

What is Roo Code?

Roo is a highly skilled software engineer assistant that lives in VS Code. Unlike proprietary tools, Roo is open-source, customizable, and respects your privacy.

Core Identity

From Roo's system prompt:

"You are Roo, a highly skilled software engineer with extensive knowledge in many programming languages, frameworks, design patterns, and best practices."

This positions Roo as an expert developer who makes conservative, precise edits.

Key Capabilities

Customizable Modes

  • Code Mode: Standard development
  • Debug Mode: Focus on debugging
  • Architect Mode: High-level design
  • Custom Modes: Create your own

Conservative Approach

  • Minimal code changes
  • Focus on maintainability
  • Careful edits
  • No unnecessary modifications

Full Control

  • Open-source codebase
  • Customizable prompts
  • Local or cloud AI
  • Privacy-focused

Standard Tools

  • Read files
  • Edit files
  • Web browse
  • Run commands
  • Search code

How Roo Code Works

Code Mode Workflow

  1. You Request

    "Add error handling to the API calls"

  2. Roo Analyzes

    • Finds API calls
    • Identifies patterns
    • Plans minimal changes

  3. Roo Implements

    • Adds try-catch blocks
    • Updates error messages
    • Maintains existing logic

  4. You Review

    • Check changes
    • Approve or modify
    • Commit when ready

Debug Mode Workflow

  1. You Report Bug

    "App crashes when clicking submit button"

  2. Roo Investigates

    • Reads relevant code
    • Identifies potential causes
    • Proposes fixes

  3. Roo Fixes

    • Makes targeted changes
    • Adds defensive code
    • Tests the fix

Custom Mode Workflow

  1. You Create Mode

    Create "Security Audit" mode with specific instructions

  2. Roo Follows

    • Uses your custom prompt
    • Applies your rules
    • Behaves as specified

System Prompt Insights

Core Philosophy

Minimal Changes:

"You complete tasks with minimal code changes and a focus on maintainability."

Conservative Behavior:

  • Won't install packages without permission
  • Won't run build commands automatically
  • Focuses on precise edits
  • Follows user's lead

Mode System

Default Modes:

  • Code: Standard development
  • Debug: Problem-solving
  • Architect: Design thinking

Customization:

  • Override default prompts
  • Add new modes
  • Per-project configuration
  • .roo files for settings

Tool Usage

Available Tools:

  • File operations
  • Code search
  • Web browsing
  • Terminal commands
  • LSP integration

Usage Philosophy: Conservative and user-approved.

Real-World Use Cases

Refactoring

Scenario: Clean up legacy code

Roo Process:

  1. Analyzes code structure
  2. Identifies improvements
  3. Makes minimal changes
  4. Preserves functionality
  5. Updates tests

Benefit: Safe refactoring

Bug Fixing

Scenario: Fix production issue

Roo in Debug Mode:

  1. Reproduces the bug
  2. Identifies root cause
  3. Proposes minimal fix
  4. Adds test case
  5. Verifies solution

Result: Targeted fix with test

Code Review

Scenario: Review pull request

Roo in Architect Mode:

  1. Analyzes changes
  2. Checks patterns
  3. Suggests improvements
  4. Identifies issues
  5. Provides feedback

Value: Expert review

Strengths

✅ Open Source

Full transparency, community-driven.

✅ Customizable

Modes, prompts, behavior—all configurable.

✅ Conservative

Minimal changes, maintainability focus.

✅ Privacy

Can use local models or your own API keys.

✅ VS Code Native

Full IDE integration.

✅ Free

No subscription required.

Weaknesses

❌ Less Polished

Not as refined as commercial tools.

❌ Setup Required

Need to configure API keys.

❌ Smaller Community

Fewer users than Cursor/Copilot.

❌ Limited Support

Community support only.

Comparison with Competitors

vs. Cursor

  • Roo: Open-source, customizable
  • Cursor: More polished, commercial

vs. GitHub Copilot

  • Roo: Free, privacy-focused
  • Copilot: More established, paid

vs. Windsurf

  • Roo: Lightweight, conservative
  • Windsurf: More autonomous, commercial

Pricing

Free and Open Source

You only pay for:

  • AI API usage (if using cloud models)
  • Or run local models for free

Best Practices

1. Choose the Right Mode

Code Mode: General development Debug Mode: Fixing issues Architect Mode: Design decisions Custom Mode: Specific workflows

2. Configure Per Project

Use .roo files to set:

  • Project-specific rules
  • Preferred patterns
  • Custom modes
  • Tool permissions

3. Review All Changes

Roo is conservative, but always:

  • Review edits
  • Understand changes
  • Test thoroughly
  • Commit consciously

4. Use Local Models

For privacy:

  • Run Ollama locally
  • Use your own models
  • Keep code private
  • No cloud dependency

5. Contribute Back

It's open source:

  • Report issues
  • Suggest features
  • Submit PRs
  • Help others

Tips for Success

1. Start with Code Mode

Learn the basics:

  • How Roo works
  • What it can do
  • How to guide it
  • When to intervene

2. Create Custom Modes

For repeated tasks:

  • Define specific behavior
  • Set clear rules
  • Save as mode
  • Reuse across projects

3. Use API Keys Wisely

Manage costs:

  • Set usage limits
  • Monitor consumption
  • Use cheaper models for simple tasks
  • Use powerful models for complex work

4. Leverage Community

Join the community:

  • Share configurations
  • Learn from others
  • Get help
  • Contribute ideas

Who Should Use Roo Code?

Perfect For:

  • Privacy-conscious developers
  • Open-source enthusiasts
  • Developers wanting customization
  • Teams with specific workflows
  • Budget-conscious users

Maybe Not For:

  • Users wanting plug-and-play
  • Those needing commercial support
  • Developers new to AI tools
  • Teams needing guaranteed uptime

The Roo Advantage

Freedom

Open source, no vendor lock-in.

Control

Customize everything.

Privacy

Your code stays yours.

Cost

Free to use.

Conclusion

Roo Code brings the power of agentic AI coding to VS Code with complete transparency and control. It's not the most polished tool, but it's the most customizable and privacy-focused.

The Roo Promise:

  • Open source
  • Customizable
  • Privacy-focused
  • Free to use

Best For: Developers who value open source, customization, and privacy over polish and convenience.

Skip If: You want a plug-and-play solution with commercial support.

Official Site: github.com/RooVetGit/Roo-Code
Best For: Open-source, customizable AI coding
Pricing: Free (pay for AI API usage)
Platform: VS Code
Updated: October 2025
Our Take: The best open-source AI coding assistant

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