Copilot for Xcode

Copilot for Xcode is an Xcode Source Editor Extension that provides Github Copilot support for Xcode. It uses the LSP provided through Copilot.vim to generate suggestions and displays them as comments.

Thanks to LSP-copilot for showing the way to interact with Copilot. And thanks to LanguageClient for the Language Server Protocol support in Swift.

Prerequisites

• Node installed to run the Copilot LSP.
• Public network connection.
• Active GitHub Copilot subscription.

Permissions Required

• Accessibility
• Folder Access
• Maybe Input Monitoring (Real-time Suggestions Only)

Installation and Setup

Install

1. Download the Copilot for Xcode.app from the latest release, and extract it to the Applications folder.

2. Open the app, and click "Set Up Launch Agents" to set up a background running XPC Service that does the real job.

3. Enable the extension in System Settings.app.

   From the Apple menu located in the top-left corner of your screen click System Settings. Navigate to Privacy & Security then toward the bottom click Extensions. Click Xcode Source Editor and tick Copilot.

   If you are using macOS Monterey, enter the Extensions menu in System Preferences.app with its dedicated icon.

Sign In GitHub Copilot

1. In the app, refresh the Copilot status (it may fail for the first time, try at least one more time).
2. Click "Sign In", and you will be directed to a verification website provided by GitHub, and a user code will be pasted into your clipboard.
3. After signing in, go back to the app and click "Confirm Sign-in" to finish.

Granting Permissions to the App

The first time the commands run, the extension will ask for the permissions needed.

Or you can add them manually by going to the Privacy & Security tab in System Settings.app, and

• Accessibility API: Click Accessibility, and add Copilot for Xcode.app to the list.
• Input Monitoring: Click Input Monitoring and add Copilot for Xcode.app to the list.

Alternative Ways to Launch the XPC Service

The launch agent is set to RunAtLoad, so it will start when you log on to your computer. If you have a solution to configure the launch agent to start and stop on demand, please file an issue or pull request (note that the XPC service must be started before the user calls any commands, as it needs to call some of the commands proactively to provide real-time suggestions).

Alternatively, you can skip the Launch Agent part and use other applications to watch Xcode launch and then launch the XPC service when needed. The executable is located at Copilot for Xcode.app/Contents/MacOS/CopilotForXcodeXPCService. Or you can remove the RunAtLoad field from the plist and run it manually.

Update

You can download the latest version manually from the latest release.

If you are upgrading from a version lower than 0.6.0, don't forget to click Restart XPC Service in the application after the update to kill the old version and start the new one.

If you want to keep track of the new releases, you can watch the releases of this repo to get notifications about updates.

If you find that some of the features are no longer working, please first try regranting permissions to the app.

Commands

• Get Suggestions: Get suggestions for the editing file at the current cursor position.
• Next Suggestion: If there is more than one suggestion, switch to the next one.
• Previous Suggestion: If there is more than one suggestion, switch to the previous one.
• Accept Suggestion: Add the suggestion to the code.
• Reject Suggestion: Remove the suggestion comments.
• Turn On Real-time Suggestions: When turn on, Copilot will auto-insert suggestion comments to your code while editing.
• Turn Off Real-time Suggestions: Turns the real-time suggestions off.
• Real-time Suggestions: Call only by Copilot for Xcode. When suggestions are successfully fetched, Copilot for Xcode will run this command to present the suggestions.
• Prefetch Suggestions: Call only by Copilot for Xcode. In the background, Copilot for Xcode will occasionally run this command to prefetch real-time suggestions.

About real-time suggestions

• The on/off state is persisted, make sure you turn it off manually if you no longer want it.

• The implementation won't feel as smooth as that of VSCode.

  The magic behind it is that it will keep calling the command from the menu when you are not typing or clicking the mouse. So it will have to listen to those events, I am not sure if people like it.

  Hope that next year, Apple can spend some time on Xcode Extensions.

Key Bindings

It looks like there is no way to add default key bindings to commands, but you can set them up in Xcode settings > Key Bindings.

A recommended setup that should cause no conflict is

Command	Key Binding
Get Suggestions	⌥?
Accept Suggestions	⌥}
Reject Suggestion	⌥{
Next Suggestion	⌥>
Previous Suggestion	⌥<

Essentially using ⌥⇧ as the "access" key combination for all bindings.

Prevent Suggestions Being Committed

Since the suggestions are presented as comments, they are in your code. If you are not careful enough, they can be committed to your git repo. To avoid that, I would recommend adding a pre-commit git hook to prevent this from happening.

#!/bin/sh

# Check if the commit message contains the string
if git diff --cached --diff-filter=ACMR | grep -q "/*========== Copilot Suggestion"; then
  echo "Error: Commit contains Copilot suggestions generated by Copilot for Xcode."
  exit 1
fi

Limitations

• The first run of the extension will be slow. Be patient.
• The extension uses some dirty tricks to get the file and project/workspace paths. It may fail, it may be incorrect, especially when you have multiple Xcode windows running, and maybe even worse when they are in different displays. I am not sure about that though.
• The suggestions are presented as C-style comments, they may break your code if you are editing a JSON file or something.

FAQ

Q: The extension doesn't show up in the Editor menu.

A: Please make sure Copilot for Xcode is turned on in System Settings.app > Privacy & Security > Extensions > Xcode Source Editor Extension.

Q: The extension says it can't connect to the XPC service/helper.

A: If you have just updated the app from an old version, make sure you have restarted the XPC Service.

Please make sure you have set up Launch Agents, try running launchctl list | grep com.intii from the terminal, and see if com.intii.CopilotForXcode.XPCService exists. If not, check ~/Library/LaunchAgents to see if com.intii.CopilotForXcode.XPCService.plist exists. If they don't, and the button in the app fails to create them, please try to do it by hand.

If you are installing multiple versions of the extension on your machine, it's also possible that Xcode is using the older version of the extension.

Q: The extension complains that it has no access to the Accessibility API

A: Check the list in System Settings.app > Privacy & Security > Accessibility. Turn the toggle on for Copilot for Xcode. If it's not on the list, add it manually.

If you have just updated the app, consider restarting XPCService in app or trying removing the Launch Agents and set it up again!

Q: I turned on real-time suggestions, but nothing happens

A: Check the list in System Settings.app > Privacy & Security > Input Monitoring. Turn the toggle on for Copilot for Xcode. If it's not on the list, add it manually. After that, you may have to restart the XPC Service.

If that doesn't help, try to restart the XPC Service again.

Q: Will it work in future Xcode updates?

A: I don't know. This extension uses many tricks to do its job, and these tricks can break in the future.