How to Use Cursor for Multi-File AI Changes in Large Codebases

Managing changes across hundreds of files in a large codebase used to mean hours of manual search-and-replace, risky grep commands, and endless code reviews. You’d open ten files at once, change a function name, then realize you missed three imports, two config files, and a test suite that broke silently. Now, with Cursor’s multi-file AI features, you can do it in minutes-without losing your mind.

What Changed in Cursor 2.0?

Cursor wasn’t always built for large codebases. When it launched in 2022, it was a smart autocomplete tool-great for single files, useless for cross-file refactors. That changed in October 2024 with Cursor 2.0. The team at Anysphere completely rebuilt the engine. They introduced Composer, a new AI model trained specifically to understand relationships between files, and a multi-agent system that runs independent AI workers in parallel, each handling a subset of files.

This wasn’t just an upgrade. It was a shift in philosophy. Instead of treating code as isolated snippets, Cursor now sees the whole project as a connected graph. It tracks imports, exports, function calls, and even unused references. That’s why it can safely rename a prop across 50 React components without breaking anything-because it knows which files actually use that prop.

How Multi-Agent Editing Works

Cursor 2.0 doesn’t just process one file at a time. It splits your task among up to eight AI agents, each working in its own isolated workspace using Git worktrees. Think of it like having eight junior developers, each assigned a chunk of files, all talking to the same central brain-the Composer model.

Here’s how it plays out in practice:

1. You type a request like: “Convert all class-based React components to functional components with hooks.”
2. Cursor scans your codebase and identifies 147 class components.
3. It splits them into eight groups, assigns each to an agent, and starts processing.
4. Each agent modifies its files, updates imports, fixes state hooks, and adjusts test files-all while checking for side effects.
5. Once done, all changes are aggregated into one clean diff.

You don’t need to manage the agents. Cursor does it automatically. But you do need to pay attention to the final diff. That’s where things get real.

What You Can Actually Do With It

The most common use cases? Refactoring. And not small stuff. Real, painful, time-sucking refactors:

• Switching from relative to absolute imports across a monorepo
• Renaming a shared utility function used in 80+ files
• Upgrading a deprecated API across an entire frontend codebase
• Converting JavaScript files to TypeScript with consistent typing
• Removing unused dependencies and cleaning up dead code

One user on Reddit refactored 150+ TypeScript files from class components to hooks in 20 minutes. That same job used to take two days manually. That’s the kind of time savings that changes how teams operate.

But it’s not magic. Cursor can’t fix bad architecture. If your code has hidden dependencies-like a config file that’s loaded dynamically, or a global variable that’s modified in three places-it might miss something. That’s why you still need to review the changes.

How to Use It Without Breaking Your Code

Using Cursor for multi-file changes isn’t just about typing a prompt. There’s a workflow that works. Skip it, and you’ll end up with half-broken code.

Here’s the step-by-step:

1. Run dependency analysis first. Go to View > Show Dependencies. This shows you how files are connected. It’s like a map before you start digging.
2. Limit your scope. Don’t try to change 200 files at once. Pick a logical group-like all files in the /components/auth/ folder. Cursor handles up to 20 files per agent best.
3. Be specific in your prompt. Instead of “Change the API endpoint,” say “Update all fetch calls in /services/ to use https://api.newdomain.com/v2 instead of https://api.old.com/v1.”
4. Review each diff. Cursor shows you a combined diff. Scroll through it. Look for files it missed. If something looks off, add that file to context and re-run.
5. Apply changes incrementally. Accept changes from one agent at a time. If something breaks, you know exactly which agent caused it.

The undo feature works per agent. So if one group of changes breaks tests, you can revert just that group without losing the other 70% of your work.

What Cursor Can’t Do (Yet)

Cursor 2.0 is powerful, but it’s not perfect. Here’s where it still stumbles:

• Hidden dependencies: If a file is imported via a string path (like require('./' + config.module)), Cursor won’t catch it.
• Extremely large codebases: Over 100,000 files, and the dependency graph gets too complex. Performance drops. You’ll need to break it into chunks.
• Order-sensitive changes: If File A must change before File B, but Cursor doesn’t detect the dependency, it might apply them in the wrong order.
• Non-code files: Configs like .env, package.json, or YAML files aren’t always analyzed with the same depth as source code.

A user on Cursor’s forum tried changing prop names across 50 React components and missed 12 files. Why? Because those files were imported through a shared index file, and Cursor didn’t trace the indirect reference. The fix? Manually add the index file to the context before running the change.

How It Compares to Other Tools

You might be thinking: “What about GitHub Copilot or Aider?” Here’s how Cursor stacks up:

Comparison of AI Code Editors for Multi-File Changes

Tool	Multi-File Support	Context Window	Agent System	Best For
Cursor 2.0	Yes, up to 8 agents	128,000 tokens	Yes, built-in	Large-scale refactors, enterprise codebases
GitHub Copilot Workspace	Partial, no persistent state	32,000 tokens	No	Quick edits, small projects
Aider	Up to 3 files per commit	16,000 tokens	No	Simple, CLI-based changes
Sweep.dev	PR-focused, limited to open changes	32,000 tokens	Yes, but tied to GitHub	Pull request automation

Cursor wins on scale and depth. It’s the only tool that treats multi-file changes as a first-class feature, not an afterthought.

Who Should Use It

If you’re working alone on a small app, you probably don’t need it. But if you’re on a team with:

• 50,000+ files
• Multiple teams touching the same code
• Legacy code that needs modernizing
• Repetitive refactors (like upgrading libraries or changing naming standards)

…then Cursor 2.0 is a game-changer. Enterprise adoption is growing fast-62% year-over-year, according to DevOps.com. Teams using it report 50%+ time savings on refactoring tasks.

Getting Started

Cursor is free for basic use. If you need unlimited multi-agent operations, the Pro plan is $20/month. Enterprise teams pay $40/user/month with custom setup options.

To start:

1. Download Cursor from cursor.sh (macOS, Windows, or Linux)
2. Open your codebase
3. Press Command+Shift+I to open the Composer prompt
4. Type your request
5. Review, adjust, apply

Most developers get comfortable in 3-5 hours. Full mastery? That takes 1-2 weeks of regular use. But the payoff is worth it.

The Future of AI Code Editing

Cursor’s roadmap includes automatic dependency graph visualization (coming Q2 2025), integration with build systems to predict impact before changes, and team-based multi-agent workflows. That last one? It’s huge. Imagine two developers assigning different agents to different parts of a refactor-and seeing real-time sync between their changes.

But here’s the truth: AI won’t replace developers. It replaces the tedious, repetitive parts. The hard decisions-when to break backward compatibility, how to structure a new module, whether to deprecate a legacy service-those still need human judgment. As Dr. Elena Rodriguez from MIT put it, “Cursor improves practical refactoring, but it can’t replace architectural thinking.”

You’re not handing off your code to a robot. You’re giving it a super-powered assistant that never gets tired, never misses a file (if you give it the right context), and lets you focus on what actually matters.