GitHub Copilot Chat is an incredibly powerful and useful feature that allows you to chat with or about your code. Even though it’s 100% natural language-friendly (i.e., you can send your messages without using any specific syntax), leveraging some special chat capabilities can unlock new AI-assisted development scenarios and significantly boost your productivity.

These powerful features, which you can use by applying special syntax, include chat participants, slash commands, and context variables. Note that the described features are available in VS Code and might not be fully supported in other IDEs where GitHub Copilot Chat is available.

Target your question or request by messaging one of the available chat participants

In GitHub Copilot Chat, you can reference one of the AI-powered “domain experts” using conventional chat syntax—by prepending @ to the participant name. The currently available chat participants are:

• @workspace: Knows everything about the code in your currently open workspace. This is the chat participant you will most likely communicate with frequently.


• @terminal: Knows all about the integrated terminal shell, its contents, and its buffer.


• @vscode: Knows about the VS Code editor, its commands, and features.

Example: Let’s get information about the backend part of the project we’ve just been assigned to by asking the @workspace chat participant right after we open the project folder in VS Code.

The @workspace chat participant is instrumental for all solution-wide queries where you want all code to be considered for the chat response. However, this doesn't mean that all code will be used and sent as part of the prompt. The GitHub Copilot Chat extension in VS Code does its best to determine relevant files and parts of these files using local knowledge and intelligence first. You can check which files and code lines were used for the prompt by expanding the “Used references” line:

Productivity hint: Use the up and down keyboard arrows to pick the chat variable you need after typing #. In the case of #file, use keyboard navigation again to pick one of the suggested files.

Call the most often used actions quickly with slash commands

Chatting with your code using natural language is fun, but having the option to call often-used actions using handy shortcuts is even better. Compare typing the full message “Explain how selected code works” versus typing “/”, then using keyboard arrows to pick /explain from the popup overlay. Another benefit of using the predefined syntax for commands is the confidence that GitHub Copilot understands our intent 100% correctly (natural language might have some ambiguity). There are a bunch of slash commands available. You can use them in conjunction with referencing the chat participant to provide the desired scope. Some of the commands are:

• /help: Help about available slash commands, chat participants, chat variables, and more.


• /doc: Generate documentation for the code.


• /explain: Explain how the code works (or get help with terminal commands if you prepend @terminal).


• /fix: Optimize and/or fix issues in the code.


• /tests: Create unit tests for the code.


• /new: Scaffold a new workspace.

Example: Let’s get an explanation for one of the regular expressions in our code. Select the code line and use the slash command “

/explain.

References