What's changed: New GH-300 Chapter 2 (IDE & CLI = enable, inline/Chat/Plan Mode, Copilot CLI, content exclusion; advanced = Edit Mode/Agent Mode/MCP, agent sessions/sub-agent delegation, code review, instructions/prompt files, PR summaries/Spaces/Spark, Chat commands/limits; org settings = policy mgmt/Code Review policy/feature availability (IDE+github.com)/audit logs/REST API subscriptions)
2.1Copilot in the IDE and CLI
Understand enabling Copilot in the IDE and using its surfaces—inline suggestions, Copilot Chat, Plan Mode, and the CLI—plus installing GitHub Copilot CLI with its key commands, and excluding specific files/repositories (content exclusion).
GitHub Copilot is usable from several surfaces. The most basic is the IDE (VS Code, Visual Studio, JetBrains, etc.); install the extension and sign in to enable it. As you type, you get inline suggestions from context, Copilot Chat lets you ask/generate/explain in natural language, and Plan Mode lets you lay out implementation steps before proceeding. There is also the GitHub Copilot CLI for the terminal.
2.1.1Enabling in the IDE and its surfaces
In the IDE, enable Copilot by installing the extension and signing in with your GitHub account. Inline suggestions propose a "continuation" from the cursor context (open files, nearby code), accepted with Tab. Copilot Chat is conversational—ask it to explain, fix, generate, or write tests, passing a selection or file as context. Plan Mode has it lay out "what to change and in what order" before writing, so you agree on a plan then implement. These are different granularities/uses of the same Copilot.
2.1.2GitHub Copilot CLI
The GitHub Copilot CLI brings Copilot to the terminal. It can suggest/explain commands, generate shell scripts, and assist with file operations via natural language—handy when you can’t recall a command or want to automate routine work. Install the CLI and authenticate with your GitHub account. Use it interactively or within a session for continuous exchanges, and run/save generated scripts directly. The benefit is Copilot assistance even in terminal-centric workflows outside the IDE.
2.1.3Excluding files/repositories (content exclusion)
To keep sensitive files or specific repositories out of Copilot’s context and suggestions, configure content exclusion. Excluded files are not used as completion context and receive no suggestions. This protects config files containing secrets or code that policy forbids sending to AI; admins set it at the repo/org level (more in Chapter 6, Privacy). Users should understand that "no suggestions here" may be due to an exclusion rule.
| Surface | Use |
|---|---|
| Inline suggestions | Suggest the "continuation" as you type |
| Copilot Chat | Conversational explain/generate/fix/test |
| Plan Mode | Plan before implementing |
| Copilot CLI | Command/script help in the terminal |
Common: (1) Enable in the IDE via extension + sign-in. (2) Surfaces = inline suggestions / Copilot Chat / Plan Mode / CLI. (3) Copilot CLI assists with commands/scripts in the terminal via natural language (install + auth, interactive/session). (4) Keep sensitive/specific repos out via content exclusion (which can explain why no suggestions appear).
Watch out: (1) Inline suggestions (automatic continuation) and Copilot Chat (conversation) are different surfaces. (2) Copilot CLI is for the terminal and installed/authenticated separately from the IDE extension. (3) "No suggestions" isn’t necessarily a bug—suspect content exclusion or file/language type. (4) Plan Mode follows "plan → implement," unlike mass-generating at once.
2.1.4Section summary
- Enable in the IDE via extension + sign-in; surfaces = inline/Chat/Plan Mode/CLI
- Copilot CLI assists commands/scripts in the terminal via natural language (install + auth, interactive/session)
- Exclude sensitive/specific repos via content exclusion (admin-set), removing them from context/suggestions
- Missing suggestions can stem from exclusions or file/language type
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Quick check
(just a quick review)Q1. For terminal-centric work you want command suggestions and shell-script generation via natural language. Which Copilot surface fits best?
Q2. You want to keep a config file with secrets out of Copilot’s context and suggestions. What do you use?
Q3. What are the basic steps to start using Copilot in the IDE?
Q4. Before starting, you want Copilot to lay out "what to change and in what order," then proceed after you agree. Which mode fits?
Q5. No suggestions appear at all in a specific file. Which cause should you suspect first?
Q6. Which correctly distinguishes inline suggestions from Copilot Chat?