Cursor

Cursor is a fork of VS Code customized for AI. It pioneered Tab-to-Complete (Copilot++) and Composer (Multi-file edits). In 2025, it is the leading "AI Native" editor.

When to Use

• Heavy AI Usage: If you copy-paste to ChatGPT 50 times a day, use Cursor.
• Legacy Refactoring: "Rewrite this entire legacy class to use React Hooks" works across multiple files.
• Speed: The "Shadow Workspace" indexing makes AI answers aware of full context instantly.

Core Concepts

Composer (Cmd+I)

A floating window that can edit multiple files simultaneously. "Add a verified field to the User model and update all call sites."

Tab (Copilot++)

Predicts your next cursor movement, not just text. It feels like mind-reading.

Indexing

Cursor locally indexes your code (embeddings) so the LLM knows about function definitions in other files without you opening them.

Best Practices (2025)

Do:

• Use Rules: Add a .cursorrules file to repo root to instruct the AI (e.g., "Always use Tailwind", "No try/catch blocks").
• Import VS Code Extensions: It takes 1 click to migrate everything from VS Code.
• Review Diffs: Cursor applies changes fast. Always review the diff (Cmd+Shift+P -> Accept).

Don't:

• Don't sleep on Model Toggle: Switch between claude-3.5-sonnet (Coding) and gpt-4o (Reasoning) depending on task.

References

• Cursor Documentation