Cursor AI Editor — Complete Setup and Workflow Guide 2026

Introduction#

Why This Matters#

Cursor is the fastest-growing AI editor for professional developers. Its fork of VS Code with deep AI integration — full repository indexing, Composer for multi-file changes, and a chat interface that understands your codebase — delivers a noticeably different experience from using Copilot as an extension. This guide walks through installation, configuration, and the specific workflows that make Cursor genuinely faster for complex development tasks.

What Cursor Is#

Cursor is a VS Code fork with AI built into the core, not bolted on as an extension. Key features:

• Tab completion — Predicts multi-line edits, not just single-line completions
• Cmd+K (Ctrl+K) — Inline AI edit within a file
• Cmd+L (Ctrl+L) — Chat panel with @codebase, @file, and @web references
• Composer (Cmd+I) — Multi-file editing from a single description
• .cursorrules — Project-level AI instructions that persist across sessions

Because it is a VS Code fork, all VS Code extensions work in Cursor. Migration is low-friction.

Installation#

# Download from cursor.com
# Available for macOS, Windows, and Linux
 
# macOS: Download cursor-mac-arm64.dmg or cursor-mac-x64.dmg
# Windows: Download cursor-win32-x64-setup.exe
# Linux: Download cursor-linux-x64.AppImage or .deb/.rpm package

On first launch, Cursor offers to import your VS Code settings, extensions, and keybindings. Say yes — you get your familiar environment immediately.

Configuration#

Model Selection#

Cursor Pro subscribers can choose their AI model per interaction:

Settings → Models → Select:
- claude-3-5-sonnet-20241022 (best for code review and analysis)
- gpt-4o (best for general coding and scaffolding)
- gpt-4o-mini (fastest, for quick completions)
- cursor-small (Cursor's own fast model for completions)

Set Claude 3.5 Sonnet as your default chat model for complex tasks.

Privacy Settings#

Settings → General → Privacy Mode
- Enabled: Code is not used for training (recommended for work on proprietary codebases)
- Business plan: All data processing stays in US/EU

.cursorrules — Teaching Cursor Your Project#

Create .cursorrules in your repository root to give Cursor persistent context about your project:

# .cursorrules example for a Python FastAPI project
 
## Project Overview
This is a FastAPI backend service for a fintech platform.
PostgreSQL database accessed via SQLAlchemy with async support.
Redis for caching and rate limiting.
 
## Coding Standards
- All functions must have type hints
- Use async/await for all database operations
- Follow the repository pattern: routes call services, services call repositories
- All endpoints must have OpenAPI documentation strings
- Use Pydantic v2 models for all request/response schemas
 
## Testing
- Use pytest with pytest-asyncio
- Mock external services using unittest.mock
- Aim for 80%+ coverage on service layer
 
## Do not
- Use synchronous database calls
- Add direct SQL in route handlers (use repository layer)
- Hardcode configuration values (use settings from config.py)

With this file, every Copilot completion, Chat answer, and Composer change follows your project conventions.

Tab Completion — Multi-Line Prediction#

Cursor's Tab completion predicts entire edit sequences, not just the next token:

# You have:
def get_user(user_id: int):
 
# You press Tab and Cursor predicts:
def get_user(user_id: int) -> Optional[User]:
    """Fetch user by ID from database."""
    return await db.get(User, user_id)
 
# If you accept and move to the next line, Cursor predicts the next logical step:
async def create_user(data: UserCreate) -> User:
    """Create a new user."""
    user = User(**data.model_dump())
    db.add(user)
    await db.commit()
    await db.refresh(user)
    return user

This is the biggest UX difference from Copilot — Cursor predicts edit sequences, not just completions.

Cmd+K — Inline Edits#

Select code, press Cmd+K (Ctrl+K), describe the change:

Selected: def get_users(): return db.query(User).all()
 
Cmd+K prompt: "Add pagination with page and per_page params, return total count"
 
Cursor generates:
async def get_users(
    page: int = 1,
    per_page: int = 20,
) -> dict:
    offset = (page - 1) * per_page
    total = await db.scalar(select(func.count(User.id)))
    users = await db.execute(
        select(User).offset(offset).limit(per_page)
    )
    return {
        "users": users.scalars().all(),
        "total": total,
        "page": page,
        "total_pages": -(-total // per_page),  # Ceiling division
    }

Composer — Multi-File Changes#

Composer (Cmd+I / Ctrl+I) is Cursor's most powerful feature. Describe a change in natural language and Cursor applies it across multiple files:

Composer prompt:
"Add email verification to the user registration flow:
1. Add an is_email_verified boolean field to the User model (default False)
2. After registration, send a verification email using the email service
3. Add a GET /verify-email?token=... endpoint
4. Store verification tokens in Redis with 24-hour expiry
5. Update tests"
 
Cursor Composer:
- Reads User model (models/user.py)
- Reads email service (services/email.py)
- Reads registration endpoint (routes/auth.py)
- Reads Redis client (utils/redis.py)
- Reads test files (tests/test_auth.py)
- Makes coordinated changes across all files
- Shows diff for review before applying

Always review the diff before accepting Composer changes — it works autonomously and may misinterpret constraints.

Chat with Codebase References#

Chat commands:
 
@codebase "How does this project handle database migrations?"
→ Searches across all files, finds Alembic config, migration scripts,
  and references in docs
 
@file:src/routes/auth.py "What's missing in the error handling here?"
→ Reads the specific file and reviews it
 
@web "What changed in SQLAlchemy 2.1?"
→ Searches the web for current documentation
 
#selection "Explain this code"
→ Explains the currently selected text

Essential Keyboard Shortcuts#

Common Mistakes#

• Not creating a .cursorrules file — Cursor gives generic suggestions without project context
• Accepting Composer changes without reviewing the diff — multi-file changes can have unintended side effects
• Using gpt-4o-mini for complex Composer tasks — use Sonnet or GPT-4o for multi-file changes where quality matters
• Not enabling Privacy Mode on proprietary codebases — code is sent to AI providers
• Expecting Composer to understand unspoken constraints — be explicit about what it should NOT do

Best Practices#

• Maintain .cursorrules as carefully as you maintain CONTRIBUTING.md — it is a first-class project artifact
• Use Cmd+K for focused single-file edits; use Composer only for changes that genuinely span multiple files
• Switch to Claude 3.5 Sonnet for code review and debugging; use GPT-4o for scaffolding new features
• Break large Composer tasks into smaller, verifiable steps rather than one massive prompt
• Test generated code before committing — Cursor generates plausible code but it requires the same review as any other code

Key Takeaways#

• Cursor is a VS Code fork — all your VS Code extensions, themes, and keybindings work immediately after import
• .cursorrules in the repository root gives Cursor persistent project-specific context for all AI interactions
• Tab completion predicts multi-line edit sequences, not just single tokens — the biggest UX difference from Copilot
• Composer (Cmd+I) applies multi-file changes from a natural language description — always review the diff before accepting
• @codebase in Chat triggers semantic search across the entire indexed repository
• Privacy Mode prevents code from being used for training — enable it for proprietary codebases
• Model selection lets you use Claude 3.5 Sonnet for analysis and GPT-4o for generation in the same session
• Cursor Pro costs $20/month; the free tier provides limited completions for evaluation