1

Copilot Architecture & Flow

What: How your prompt flows through Copilot β€” context is gathered, routed via a proxy to the AI model, filtered for safety, and returned as a response.
HOW YOUR PROMPT FLOWS THROUGH COPILOT πŸ’¬ User Prompt Chat Β· Inline Β· CLI Completions πŸ“‚ Context Gathering Open tabs Β· #file Β· #codebase Instructions Β· Skills πŸ›‘οΈ Pre-Model Filters Responsible AI Content Exclusion πŸ”€ Proxy Service Routes to model Applies policies 🧠 AI Model GPT Β· Sonnet Β· Gemini Opus Β· Grok Β· etc. User-selected or auto πŸ” Post-Model Filters Duplicate code check Safety & quality Response delivered to user CONTEXT SOURCES πŸ“„ Open Tabs Active editor files πŸ“ Workspace #codebase search πŸ“‹ Instructions .md config files 🧩 Skills SKILL.md bundles πŸ”Œ MCP Servers External tools/data βœ‚οΈ Selection #selection context 🌐 Web Pages #fetch URL content OUTPUT TYPES ⌨️ Inline Completions πŸ’¬ Chat Responses πŸ”§ Agent Actions πŸ“ Code Edits πŸ—οΈ Terminal Commands
Key Stages
  • Context gathering β€” workspace files, open tabs, selections, instructions
  • Pre-model filters β€” responsible AI, content exclusion
  • Proxy service β€” routes to chosen model, applies policies
  • AI model β€” user picks model or auto-select (10% discount)
  • Post-model filters β€” duplicate code detection, safety checks
Installation
ext install GitHub.copilot ext install GitHub.copilot-chat
πŸ’‘ Your code is never stored or used for training (Business/Enterprise). Prompts are not retained after the response is delivered.
Use Cases
Debug unexpected output β€” understand why Copilot gave a wrong answer (check if context was gathered correctly)
Explain to stakeholders β€” describe how code never leaves the proxy pipeline (security/compliance reviews)
2

Chat Experience

What: The conversational AI panel in VS Code. Use slash commands, context variables (#), and participants (@) to give Copilot precise context for better answers.
ANATOMY OF A COPILOT CHAT PROMPT / Slash Commands /explain /fix /tests What to do # Context Variables #file #codebase #changes What to include @ Participants @workspace @github Who to ask πŸ’¬ Assembled Prompt /explain #file:auth.ts "How does the login flow work?" Your natural language question + structured context ✨ AI Response Explanation, code edit, tests, scaffold, or fix CHAT MODES πŸ’¬ Ask ✏️ Edit πŸ€– Agent πŸ“‹ Plan ⌘I Inline Chat βŒƒβŒ˜I Panel Β· ⌘I Inline Β· πŸŽ™οΈ Voice
Slash Commands
CommandActionCommandAction
/explainExplain selected code/fixFix problems in code
/testsGenerate unit tests/newScaffold new project
/clearNew chat session/helpCopilot quick reference
/delegateSend to coding agent/searchWorkspace search
/initGenerate instructions/compactCompress context
Context Variables (#)
#fileInclude file content
#selectionSelected text
#codebaseFull workspace context
#problemsError/warning diagnostics
#changesGit changes (diff)
#fetchFetch a web page
#terminalLastCommandLast terminal output
#block #class #functionCode scope
Chat Participants (@)
@workspaceProject structure & code
@vscodeVS Code commands & features
@terminalTerminal shell context
@githubGitHub-specific skills
@azureAzure services help
Voice Chat
  • Install ms-vscode.vscode-speech
  • Dictate prompts hands-free
Use Cases
/explain + #file β€” "Explain the auth flow in #file:auth.ts" (onboard to unfamiliar code)
/fix + #problems β€” "Fix all errors in #problems" (resolve build failures in one prompt)
3

Code Completions

What: Real-time ghost text suggestions as you type. Copilot predicts your next lines of code based on context β€” accept with Tab, dismiss with Esc.
HOW CODE COMPLETIONS WORK ⌨️ You Type Code Comment, function sig, variable name, pattern πŸ‘» Ghost Text Appears Greyed-out inline suggestion Multiple alternatives available βœ… Accept β€” Tab Inserts full suggestion ❌ Dismiss β€” Esc Ghost text disappears πŸ”„ Cycle β€” Alt+] / [ Browse alternative suggestions shows next/prev alternative βœ‚οΈ Partial β€” Ctrl+β†’ Accept word by word app.py β€” VS Code 12 13 14 15 16 # fetch user by email from the database def fetch_user_by_email ( email : str ): """Fetch a user record from the database by email.""" query = "SELECT * FROM users WHERE email = %s" return db.execute(query, (email,)).fetchone() πŸ‘» Ghost Text Press Tab to Accept
Keyboard Shortcuts
TabAccept full suggestion
EscDismiss suggestion
Alt+] / Alt+[Cycle alternatives
Ctrl+β†’Accept word by word
Enable / Disable
  • Toggle from Copilot icon in status bar
  • Disable for specific languages in settings
  • Snooze β€” temporarily pause suggestions
Completions Model
  • Change model in settings for inline suggestions
  • Premium models consume premium requests
  • Free plan: 2,000 completions/month
πŸ’‘ Write a descriptive comment first β€” Copilot uses it as a prompt to generate the function body below.
Use Cases
Write a function from a comment β€” type // fetch user by email, Copilot generates the implementation
Auto-complete test cases β€” write one it("should...") block and Tab through the rest
4

Next Edit Suggestions (NES)

What: Predicts your next edit based on recent changes, not just cursor position. Jumps you to the right location and suggests the change β€” great for repetitive multi-location refactors.
HOW NEXT EDIT SUGGESTIONS WORK ✏️ You Make an Edit Rename, refactor, add code in one location 🧠 NES Detects Pattern Analyzes your change and finds similar locations ➑️ Arrow β†’ Appears Indicator points to the next suggested edit location βœ… Tab to Accept Applies the suggested edit at that location πŸ” Repeat Tab again for next location jumps to next matching location BEFORE (your edit) AFTER (NES applies) 5 const userId = getUser (); accountId 8 console.log( userId ); ← still old name 15 fetchData( userId ); ← still old name β†’ NES 5 const accountId = getUser(); 8 console.log( accountId ); βœ… fixed 15 fetchData( accountId ); βœ… fixed
How It Works
  • Monitors your editing patterns across files
  • Suggests edits at locations you haven't navigated to yet
  • Shows arrow indicator β†’ jump to suggested edit
  • Tab to accept, Tab again to jump to next
Why Use It
  • Rename variables across multiple locations
  • Apply consistent pattern changes
  • Add missing imports after using a new API
Use Cases
Rename userId β†’ accountId β€” change one occurrence, NES finds and fixes the rest across files
Add error handling β€” wrap one function in try/catch, NES suggests the same for similar functions
5

Inline Chat

What: Chat with Copilot directly inside your editor or terminal without switching to the sidebar. Get targeted code edits, command generation, and image-to-code conversion in context.
INLINE CHAT WORKFLOW IN EDITOR β€” ⌘I / Ctrl+I πŸ–±οΈ Select Code (optional β€” or place cursor) πŸ’¬ ⌘I β†’ Type Prompt "Extract into a custom hook" πŸ“Š Preview Diff Review changes inline βœ… Accept / Discard Apply edits or reject IN TERMINAL β€” ⌘I $ ⌘I β†’ "Find all .log files > 100MB and delete them" Copilot generates: find . -name "*.log" -size +100M -delete ↑ Run or Copy VISION INPUT β€” Attach Images πŸ–ΌοΈ UI mockup β†’ ⌘I + πŸ“Ž image "Build this login form using React + Tailwind" β†’ πŸ“„ Generated
In Editor
  • ⌘I (Mac) / Ctrl+I (Win) β€” open inline chat
  • Select code first for targeted edits
  • Supports context vars & model selection
  • Preview diff before accepting
In Terminal
  • ⌘I in terminal β€” generate commands
  • Copilot understands shell context
  • Generates and explains terminal commands
Vision Input
  • Attach images to chat prompts
  • UI mockups β†’ code generation
Use Cases
Refactor selected code β€” select a function, ⌘I β†’ "Extract this into a custom hook" (targeted in-place edit)
Generate shell commands β€” ⌘I in terminal β†’ "Find all .log files larger than 100MB and delete them"
6

Model Selection & Premium Requests

What: Choose from 20+ AI models. Each model has a premium request multiplier β€” included models (GPT-4.1, GPT-4o, GPT-5 mini) cost 0Γ—, while advanced models cost 1×–30Γ—. Manage your monthly budget accordingly.
MODEL COST TIERS β€” PICK THE RIGHT MODEL FOR THE TASK πŸ†“ 0Γ— INCLUDED No premium requests consumed GPT-4.1 GPT-4o GPT-5 mini Raptor mini Best for: boilerplate, simple edits πŸ’° 0.25–0.33Γ— Budget-friendly premium Grok Code Fast 1 Claude Haiku 4.5 Gemini 3 Flash GPT-5.1 Codex Mini Best for: fast iteration, tests ⚑ 1Γ— STANDARD Full premium request per use Sonnet 4 / 4.5 / 4.6 Gemini 2.5/3/3.1 Pro GPT-5.1 / 5.2 / 5.4 GPT-5.1 Codex Best for: complex refactors, agents πŸ”₯ 3–30Γ— PREMIUM High cost β€” use sparingly Opus 4.5 3Γ— Opus 4.6 3Γ— Opus 4.6 fast 30Γ— Best for: architecture, design β—€ β–Ά FREE EXPENSIVE COST β†’
Model Multipliers (Paid Plans)
ModelRate
GPT-4.1 / GPT-4o / GPT-5 mini0Γ— included
Raptor mini0Γ— included
Grok Code Fast 10.25Γ—
Claude Haiku 4.5 / Gemini 3 Flash0.33Γ—
GPT-5.1-Codex-Mini / GPT-5.4 mini0.33Γ—
Sonnet 4 / 4.5 / 4.61Γ—
Gemini 2.5 Pro / 3 Pro / 3.1 Pro1Γ—
GPT-5.1 / 5.2 / 5.4 + Codex variants1Γ—
Claude Opus 4.5 / 4.63Γ—
Opus 4.6 fast mode (preview)30Γ—
Plans & Allowances
PlanIncluded
Free2K completions + 50 premium/mo
Pro / StudentUnlimited + premium allowance
Pro+Unlimited + higher premium
BusinessUnlimited + org premium pool
EnterpriseUnlimited + enterprise premium
πŸ’‘ Auto model selection gives 10% multiplier discount on paid plans.
⚠️ Unused requests don't carry over. Counters reset on 1st of each month (UTC).
πŸ“Œ Models are frequently added and deprecated. Multipliers may change. Check official docs for the latest model list.
Use Cases
Save budget on simple tasks β€” use GPT-4.1 (0Γ—) for boilerplate, switch to Sonnet 4.6 (1Γ—) for complex refactors
Architecture decisions β€” use Opus 4.6 (3Γ—) for design reviews where quality matters more than cost
7

Custom Instructions

What: Markdown files that automatically inject your coding standards, conventions, and project context into every Copilot request β€” no need to repeat yourself in prompts.
INSTRUCTION PRIORITY β€” WHICH FILE WINS? β‘  PERSONAL Highest priority ~/.copilot/instructions/ β‘‘ REPOSITORY Per-project rules .github/copilot-instructions.md β‘’ ORGANIZATION Lowest priority GitHub org settings HIGH LOW ALWAYS-ON FILES copilot-instructions.md AGENTS.md CLAUDE.md Task-specific: commitMessageGeneration Β· reviewSelection Β· pullRequestDescription Β· Generate with /init
Always-On Files
copilot-instructions.md.github/ folder
AGENTS.mdRoot or subfolders
CLAUDE.mdRoot, .claude/, ~/
For Specific Tasks
Code reviewreviewSelection.instructions
CommitscommitMessageGeneration
PR descriptionspullRequestDescription
Priority (High β†’ Low)
  • 1. Personal (user-level)
  • 2. Repository (.github/ or AGENTS.md)
  • 3. Organization
Generate Instructions
  • /init β€” auto-generate for workspace
  • /create-instruction β€” AI-assisted
  • Chat debug view β†’ verify loaded files
Use Cases
Enforce coding style β€” add "Always use single quotes and 2-space indentation" to copilot-instructions.md
Standardize commit messages β€” set commitMessageGeneration instructions to follow Conventional Commits format
8

Instructions.md Files

What: Targeted instruction files (.instructions.md) that apply conditionally based on file glob patterns or semantic matching β€” e.g., Python rules only for *.py files.
CONDITIONAL INSTRUCTIONS β€” applyTo GLOB MATCHING .github/instructions/ πŸ“„ python.instructions.md **/*.py πŸ“„ react.instructions.md **/*.tsx πŸ“„ tests.instructions.md **/*.test.* πŸ“„ api.instructions.md **/api/** match πŸ“ You're editing: src/utils/auth.py inject πŸ’¬ Copilot Prompt (enriched) System instructions injected: βœ… python.instructions.md ❌ react.instructions.md ❌ tests.instructions.md ❌ api.instructions.md Only python.instructions.md matches auth.py via applyTo: '**/*.py' β€” others are skipped
Format
--- name: 'Python Standards' description: 'Python conventions' applyTo: '**/*.py' --- # Python coding standards - Follow PEP 8 style guide - Use type hints for all functions
Locations
Workspace.github/instructions/
Claude fmt.claude/rules/
User~/.copilot/instructions/
πŸ’‘ Type /instructions in chat to open Configure menu.
Use Cases
Python-only rules β€” create python.instructions.md with applyTo: '**/*.py' for PEP 8, type hints, docstrings
React testing patterns β€” create react-tests.instructions.md with applyTo: '**/*.test.tsx' for RTL best practices
9

Reusable Prompt Files

What: Saved prompt templates (.prompt.md) you invoke as slash commands. Encode frequent tasks like scaffolding components or running reviews β€” type /prompt-name instead of re-writing the prompt.
HOW PROMPT FILES WORK πŸ“ Create .prompt.md πŸ’¬ Type /name in chat to invoke ⚑ AI Executes with tools & model PROMPT FILE ANATOMY --- description Β· agent Β· tools Β· model --- + prompt body Variables: ${input:name} Β· ${selection} Β· ${file} Β· Markdown links to instructions
  • Encode common tasks as .prompt.md files
  • Invoke via /prompt-name in chat
  • Workspace: .github/prompts/
  • User: profile prompts/ folder
Format
--- description: 'Create React form' agent: agent tools: ['editFiles', 'search'] model: GPT-5.2 --- Generate a React form component with validation for ${input:fields}
Quick Commands
/create-promptAI-generate a prompt file
/promptsConfigure prompt files
πŸ’‘ Reference instructions via Markdown links. Use ${selection} for flexibility.
Use Cases
One-command API scaffold β€” /create-api generates REST endpoint with controller, service, tests, and OpenAPI spec
Standardized code review β€” /review-pr checks for security, performance, and accessibility issues every time
10

Chat Modes & Custom Agents

What: Agents are specialized AI personas with their own tools, instructions, and model. Create a security reviewer, planner, or any role β€” each with restricted tool access and handoffs to other agents.
BUILT-IN MODES vs CUSTOM AGENTS BUILT-IN MODES πŸ’¬ Ask Read-only Q&A ✏️ Edit Direct code edits πŸ€– Agent Autonomous + tools πŸ“‹ Plan Plan before code vs CUSTOM AGENT (.agent.md) πŸ›‘οΈ Your Agent reviewer.agent.md Custom instructions πŸ”§ tools[] 🧠 model πŸ€– agents[] πŸ”Œ MCP HANDOFF WORKFLOW πŸ›‘οΈ Review πŸ”¨ Fix βœ… Validate
Built-in Modes
ModePurpose
AskRead-only Q&A, no code changes
EditDirect code edits
AgentAutonomous tool use + edits
PlanCreate plan before implementation
Custom Agent File (.agent.md)
--- description: 'Security reviewer' tools: ['search', 'readFile'] model: Claude Sonnet 4.6 handoffs: - label: Fix issues agent: implementation --- Review code for OWASP Top 10...
Agent Frontmatter Fields
descriptionShown as placeholder text
toolsList of available tools
agentsAllowed subagents (* = all)
modelAI model (string or priority list)
handoffsSequential workflow transitions
targetvscode or github-copilot
mcp-serversMCP server configs
hooksAgent-scoped hooks (Preview)
Locations
Workspace.github/agents/
Claude fmt.claude/agents/
User~/.copilot/agents/
πŸ’‘ Type /agents or /create-agent in chat to manage agents.
Use Cases
Security review agent β€” read-only tools (search, readFile), scans for OWASP Top 10, hands off to "fix" agent
Plan β†’ Implement workflow β€” Plan agent creates a spec, handoff button sends it to Agent mode for coding
11

Skills (Agent Superpowers)

What: Portable folders of instructions, scripts & resources that Copilot auto-loads when relevant. Unlike instructions (guidelines), skills teach capabilities β€” testing workflows, deployment recipes, etc. Open standard across VS Code, CLI & coding agent.
HOW SKILLS LOAD β€” PROGRESSIVE CONTEXT REQUEST 1 πŸ“‹ Metadata name + description Γ— all skills 🧠 Prompt Match AI matches prompt to skill descriptions βœ… Best match testing skill selected for loading πŸ’‘ Only metadata is sent initially β€” not full SKILL.md REQUEST 2 πŸ“„ SKILL.md Full instructions loaded into context πŸ€– Agent reads: β€’ Workflow steps β€’ Patterns & rules πŸ’‘ Only matched skill's SKILL.md is loaded Agent now knows HOW to perform the task but hasn't loaded helper files yet REQUEST 3+ πŸ“¦ Resources Scripts, templates, fixtures loaded ⚑ Executes Agent uses helpers to complete task πŸ’‘ Progressive loading saves tokens Helper scripts, test templates, fixtures loaded only when agent needs them πŸ”„ All automatic β€” just place skills in .github/skills/ β€” Copilot handles matching & loading
SKILL.md Format
--- name: webapp-testing description: 'Run and debug web app integration tests' --- # Testing Workflow Use describe + it + AAA pattern Use factory mocks for fixtures
Locations
Project.github/skills/<name>/
Personal~/.copilot/skills/<name>/
Key Features
  • Invoke via /skill-name in chat
  • /create-skill β€” AI-generate a skill
  • Works across VS Code, CLI & coding agent
  • Open standard: agentskills.io
Use Cases
Testing skill β€” SKILL.md + test templates + fixture scripts β†’ Copilot auto-loads when you ask "help me test"
Deployment skill β€” SKILL.md + deploy scripts + Dockerfile β†’ /deploy runs the full pipeline
12

MCP β€” Model Context Protocol

What: An open standard that connects Copilot to external tools & services (databases, APIs, browsers). MCP servers expose tools, data resources, and prompt templates that the AI can use during conversations.
MCP β€” HOW COPILOT CONNECTS TO EXTERNAL TOOLS 🧠 Copilot Agent Discovers & calls tools via MCP protocol requests β†’ ← responses πŸ”Œ MCP Server stdio / HTTP transport Exposes capabilities EXTERNAL SERVICES πŸ—„οΈ Databases 🌐 APIs 🧭 Browsers πŸ“ File Systems πŸ™ GitHub πŸ”§ Custom Tools MCP CAPABILITIES πŸ”§ Tools πŸ“„ Resources πŸ’¬ Prompts πŸ–₯️ MCP Apps πŸ”„ Sampling ❓ Elicitation πŸ–οΈ Sandbox
mcp.json (.vscode/mcp.json)
{ "servers": { "github": { "type": "http", "url": "https://api.githubcopilot.com/mcp" }, "playwright": { "command": "npx", "args": ["-y", "@microsoft/mcp-server-playwright"] } } }
MCP Capabilities
CapabilityDescription
ToolsExecute operations (file, DB, API)
ResourcesRead-only context (Add Context β†’ MCP Resources)
PromptsTemplates via /server.prompt
MCP AppsInteractive UI in chat
SamplingServer-initiated model calls
ElicitationServer asks user for input
Key Servers
github-mcp-serverGitHub APIs
PlaywrightBrowser automation
SandboxmacOS/Linux: sandboxEnabled
⚠️ Only use MCP servers from trusted sources. Review configs before starting.
Use Cases
Query a database β€” add a Postgres MCP server β†’ ask Copilot "show me users who signed up this week"
Browser testing β€” add Playwright MCP server β†’ "go to our staging site and screenshot the login page"
13

Hooks β€” Lifecycle Automation

What: Deterministic shell commands that run at specific agent lifecycle points. Unlike instructions (suggestions), hooks guarantee execution β€” block dangerous commands, auto-format after edits, log tool usage, enforce security policies.
AGENT LIFECYCLE β€” WHERE HOOKS FIRE SessionStart πŸš€ Session begins UserPromptSubmit πŸ’¬ User sends prompt PreToolUse πŸ›‘οΈ Before tool runs PostToolUse πŸ” After tool completes PreCompact πŸ“¦ Before compaction Stop 🏁 Session ends EXIT CODES βœ… 0 = Success β†’ continue 🚫 2 = Block β†’ stop agent ⚠️ Other = Warning β†’ continue
Hook Events
EventWhen
SessionStartFirst prompt of new session
UserPromptSubmitUser submits a prompt
PreToolUseBefore tool invocation
PostToolUseAfter tool completes
PreCompactBefore context compaction
SubagentStart/StopSubagent lifecycle
StopAgent session ends
Hook Config (.github/hooks/*.json)
{ "hooks": { "PostToolUse": [{ "type": "command", "command": "npx prettier --write \"$TOOL_INPUT_FILE_PATH\"" }] } }
Exit Codes
0Success β†’ parse stdout JSON
2Block β†’ stop & show error
OtherWarning β†’ continue
PreToolUse Output
permissionDecision"allow" | "deny" | "ask"
πŸ’‘ Use /hooks or /create-hook in chat to configure hooks.
Use Cases
Auto-format on save β€” PostToolUse hook runs prettier --write on every file the agent edits
Block destructive commands β€” PreToolUse hook denies rm -rf and DROP TABLE with exit code 2
14

Copilot on GitHub.com

What: Copilot features on github.com β€” the cloud coding agent creates PRs autonomously, Copilot reviews code, generates PR summaries, helps with issues, and runs Autofix for security vulnerabilities.
CODING AGENT WORKFLOW ON GITHUB.COM πŸ“‹ Delegate Issue or /delegate πŸ€– Agent Codes Branch + implement πŸ”€ Opens PR Auto-created πŸ‘€ Review Merge GITHUB.COM FEATURES πŸ“ PR Summary πŸ” Code Review πŸ› Issue Helper πŸ›‘οΈ Autofix
Coding Agent
  • Delegate tasks from VS Code, CLI, or github.com
  • Use /delegate in chat or @cli in terminal
  • Creates PRs autonomously in cloud
  • Uses premium requests (1Γ— per session Γ— model)
  • Follow up with steering comments
PR & Issue Features
  • PR Summary β€” auto-generate descriptions
  • Code Review β€” assign Copilot as reviewer
  • Issue helper β€” create/update issues with Copilot
  • Autofix β€” code scanning security fixes
Customize Agent Environment
  • Custom Dockerfile, devcontainer
  • MCP servers for coding agent
  • Pre/post scripts, dependencies
Use Cases
Delegate a feature β€” /delegate + link to GitHub issue β†’ agent creates a branch, implements, and opens a PR
Auto-review PRs β€” assign Copilot as reviewer on every PR β†’ catches bugs, style issues, and security flaws
15

Copilot CLI β€” Terminal AI Agent

What: A full AI coding agent in your terminal β€” interactive conversations, autonomous task execution, plan mode, custom agents, MCP, hooks, skills, and memory. Default model: Claude Sonnet 4.5.
COPILOT CLI β€” TERMINAL INTERFACE Terminal β€” copilot ❯ copilot "Add input validation to all API endpoints and write tests" πŸ€– Agent πŸ’¬ Ask πŸ“‹ Plan Shift+Tab: toggle mode Ctrl+T: show reasoning @file: add context !cmd: run shell β ‹ Reading codebase... β†’ Found 6 API endpoints β†’ Adding Zod schemas... βœ“ 12 files modified, 47 tests pass FLAGS: -p "prompt" --continue --resume --agent=name --allow-all-tools --model name --allow-tool='shell(git)'
Slash Commands
CommandAction
/modelSwitch AI model
/compactCompress conversation context
/contextView token usage breakdown
/usageSession stats (premium reqs, duration, LOC)
/agentSelect a custom agent
/mcpList MCP servers; /mcp add to add
/resumeResume a previous session
/add-dirTrust an additional directory
/cwd / /cdChange working directory
/loginAuthenticate with GitHub
/feedbackSubmit feedback, bugs, features
/allow-allAuto-approve all tools this session
Keyboard & Syntax
Key / SyntaxAction
Shift+TabToggle Ask / Plan mode
Ctrl+TShow/hide model reasoning
EscStop current operation
@path/to/fileInclude file as context
!git statusRun shell command directly
Command-Line Flags
-p "prompt"Programmatic single-prompt mode
--continueResume most recent session
--resumePick a session to resume
--agent=nameUse a specific custom agent
--allow-all-toolsAuto-approve all tools
--allow-tool='shell(git)'Allow specific tool
--deny-tool='shell(rm)'Block specific tool
--model nameSet model from CLI
Built-in Subagents
ExploreQuick codebase analysis
TaskRun tests/builds, brief summaries
Code-reviewReview changes, surface real issues
Use Cases
Headless automation β€” copilot -p "Run tests, fix failures, commit" --allow-all-tools in CI/CD
Resume cloud agent β€” /resume to pull a coding agent session from github.com into your terminal
πŸ“š Sources: GitHub Docs β€” Copilot CLI
16

Spaces & Spark

What: Spaces β€” curated knowledge collections for project context. Spark β€” natural language to micro web apps.
πŸ“š Copilot Spaces Curated knowledge collections πŸ“„ Docs + πŸ’» Code + πŸ“ Files β†’ Shared project context β†’ github.com/copilot/spaces 1Γ— premium/request ⚑ Copilot Spark Natural language β†’ web apps πŸ’¬ "Build a dashboard for..." β†’ Live micro web app in seconds β†’ github.com/spark 4Γ— premium/prompt
  • Curate knowledge for project context
  • Attach docs, code, files to a space
  • Access at github.com/copilot/spaces
  • Uses premium requests (1Γ— model rate)
Copilot Spark
  • Natural language β†’ micro web apps
  • 4 premium requests per prompt
  • Access at github.com/spark
Use Cases
CLI: bulk file ops β€” copilot -p "Rename all .jpeg files to .jpg recursively" with --allow-tool='shell'
Spark: quick prototype β€” "Build a dashboard showing my GitHub repo stats" β†’ live web app in seconds
17

Toolsets

What: A collection of tools you reference as a single entity in prompts, prompt files, and custom agents. Organize related tools and enable/disable them as a group.
GROUP TOOLS β†’ REFERENCE AS ONE INDIVIDUAL TOOLS πŸ” search/codebase πŸ“„ search/changes ⚠️ read/problems πŸ”— search/usages group πŸ“¦ #reader Toolset 4 tools bundled .jsonc config use USE IN πŸ’¬ Prompts #reader πŸ€– Agents tools: ['reader']
  • Define in .jsonc files via Chat: Configure Tool Sets
  • Reference in prompts: #toolset-name
  • Reference in agents: tools: ['my-toolset']
  • Built-in sets: #edit, #search
Tool Set File (.jsonc)
{ "reader": { "tools": ["search/changes", "search/codebase", "read/problems", "search/usages"], "description": "Tools for reading context", "icon": "book" } }
Properties
toolsArray of tool names (built-in, MCP, extension)
descriptionShown in tools picker
iconProduct icon (see Icon Reference)
Use Cases
Read-only toolset β€” group search, readFile, grep into a #reader set for safe auditing
Quick reference β€” type #reader in prompt to enable all read tools at once
πŸ“š Sources: VS Code Docs β€” Tool Sets
18

Content Exclusion

What: Organization-level rules that prevent specific files, folders, or repositories from being sent to the AI model β€” enforcing compliance and protecting sensitive code.
CONTENT EXCLUSION β€” WHAT GETS BLOCKED 🚫 EXCLUDED FILES πŸ”’ .env / .env.* πŸ”‘ **/secrets/** πŸ“œ **/keys/** 🏒 internal-repo πŸ›‘οΈ BLOCKED Not sent to AI model βœ… APPLIES TO ⌨️ Completions πŸ’¬ Chat & Inline Chat πŸ€– Agent Mode
  • Exclude files/repos from Copilot at org level
  • Prevents content from being sent to model
  • Configurable in GitHub org settings
  • Supports glob patterns for paths
  • Applies to completions, chat, and agents
Common Exclusions
.env / .env.*Environment variables & secrets
**/secrets/**Secret files & credentials
**/keys/**API keys & certificates
internal-repoEntire private repositories
Use Cases
Exclude secrets β€” content exclusion rule blocks .env, **/secrets/** from being sent to AI
Compliance β€” exclude regulated codebases (HIPAA, PCI) from AI processing at the org level
19

Spec-Driven Development

What: Write a specification first, then let the AI agent implement it. Specs define requirements, acceptance criteria, and architecture β€” giving agents a clear blueprint instead of ad-hoc prompts.
SPEC-DRIVEN WORKFLOW πŸ“ Write Spec Requirements + acceptance criteria πŸ‘€ Review Refine & validate spec πŸ€– Implement Agent codes from blueprint βœ… Validate Tests pass criteria met Frameworks: spec-kit Β· OpenSpec Β· BMAD Β· GSD
Popular Frameworks
spec-kitGitHub's spec workflow for coding agent
OpenSpecFission AI spec framework
BMADBMAD methodology
GSDGet-shit-done framework
Workflow
Write Spec β†’ Review & Refine β†’ Agent Implements β†’ Validate Output
Use Cases
Feature spec β€” write a spec with user stories + acceptance criteria β†’ /delegate to coding agent for implementation
Migration spec β€” define the target state, constraints, and rollback plan β†’ agent handles the migration systematically
πŸ“š Sources: github/spec-kit · OpenSpec · BMAD Method · GSD
20

Customization File Structure

What: The recommended project layout for all Copilot customization files β€” instructions, prompts, agents, skills, hooks, toolsets, and MCP configs in one organized tree.
CUSTOMIZATION FILE LOCATIONS .github/ instructions/ prompts/ agents/ skills/ hooks/ toolsets/ copilot-instructions.md Root: AGENTS.md Β· CLAUDE.md | .vscode/: mcp.json | User: ~/.copilot/
your-project/ β”œβ”€β”€ .github/ β”‚ β”œβ”€β”€ copilot-instructions.md β”‚ β”œβ”€β”€ instructions/ β”‚ β”‚ β”œβ”€β”€ python.instructions.md β”‚ β”‚ └── react.instructions.md β”‚ β”œβ”€β”€ prompts/ β”‚ β”‚ └── create-api.prompt.md β”‚ β”œβ”€β”€ agents/ β”‚ β”‚ β”œβ”€β”€ planner.agent.md β”‚ β”‚ └── reviewer.agent.md β”‚ β”œβ”€β”€ skills/ β”‚ β”‚ └── testing/ β”‚ β”‚ └── SKILL.md β”‚ β”œβ”€β”€ hooks/ β”‚ β”‚ └── format.json β”‚ └── toolsets/ β”œβ”€β”€ .vscode/ β”‚ └── mcp.json β”œβ”€β”€ AGENTS.md └── CLAUDE.md
Use Cases
Monorepo setup β€” separate instructions/ for frontend (React) and backend (Python) with different applyTo globs
Team shared configs β€” commit .github/ folder to Git so all team members get the same Copilot behavior
21

Third-Party Coding Agents

What: Use Anthropic Claude and OpenAI Codex as autonomous coding agents alongside Copilot's built-in agent. Assign GitHub issues or prompts β€” they create branches, implement changes, and open PRs for review.
THIRD-PARTY CODING AGENTS β€” ASSIGN & COMPARE Claude Anthropic Β· Preview Copilot GitHub Β· GA Codex OpenAI Β· Preview WORKFLOW πŸ“‹ Assign Issue πŸ€– Agent Codes πŸ”€ Opens PR Cost: GitHub Actions minutes + 1 premium request per session AVAILABLE FROM 🌐 GitHub.com πŸ–₯️ VS Code πŸ“± GitHub Issues πŸ’¬ PR Comments πŸ“± Mobile ⌨️ CLI
Supported Agents
AgentProviderStatus
ClaudeAnthropicPreview
CodexOpenAIPreview
CopilotGitHubGA
Where to Use
  • Agents tab β€” github.com/copilot/agents
  • Issues β€” assign the agent to an issue
  • PRs β€” mention @AGENT_NAME in a comment
  • VS Code β€” new session β†’ select agent type
  • GitHub Mobile β€” start agent session from Home
How It Works
Assign Issue / Prompt β†’ Agent Plans & Codes β†’ Opens PR β†’ You Review
Cost & Billing
  • Consumes GitHub Actions minutes + 1 premium request per session
  • Uses same security protections as Copilot coding agent
  • Same repo access permissions as built-in agent
Enable for Your Org
  • Org Settings β†’ Copilot β†’ Coding agent β†’ Partner agents
  • Available on Pro, Pro+, Business, and Enterprise plans
  • Org admins toggle each agent independently
⚠️ Third-party agents are in public preview. Policies apply to cloud agents only β€” local agents in VS Code cannot be disabled.
Use Cases
Compare agent output β€” assign the same issue to Claude, Codex, and Copilot β†’ compare the three PRs and merge the best one
Parallel workstreams β€” assign backend refactor to Codex while Claude handles frontend tests β€” both open PRs simultaneously
22

Browser Agent Tools

What: Agents can open, interact with, and screenshot web pages in VS Code's integrated browser β€” enabling autonomous build β†’ test β†’ debug β†’ fix loops for web apps without leaving the editor.
AUTONOMOUS DEV LOOP β€” BUILD β†’ TEST β†’ FIX πŸ—οΈ Build App Agent writes code 🌐 Open in Browser openBrowserPage πŸ–±οΈ Test & Interact click Β· type Β· screenshot πŸ”§ Fix Issues Auto-fix from errors βœ… Validate Screenshot & verify repeat until all tests pass KEY TOOLS openBrowserPage screenshotPage clickElement typeInPage readPage handleDialog runPlaywrightCode
Available Tools
ToolAction
openBrowserPageOpen a URL in integrated browser
navigatePageNavigate to a different URL
readPageRead page content & structure
screenshotPageTake a screenshot for visual review
clickElementClick a page element
hoverElementHover over an element
dragElementDrag and drop elements
typeInPageType text into inputs
handleDialogAccept/dismiss browser dialogs
runPlaywrightCodeRun custom Playwright automation
Enable Browser Tools
  • Set workbench.browser.enableChatTools to true
  • Open Chat β†’ Agent mode β†’ Tools picker
  • Enable all tools under Built-in > Browser
Autonomous Dev Loop
Build App β†’ Open in Browser β†’ Test & Interact β†’ Fix Issues β†’ Validate
Sharing Pages
  • Agent-opened pages use isolated ephemeral sessions (no shared cookies)
  • Share with Agent button β€” share your pages (uses your session/cookies)
  • Visual indicator shows when a page is shared
⚠️ Browser agent tools are experimental and may change in future releases.
Use Cases
Form validation testing β€” "Build a contact form, open it in the browser, test all validation rules and fix any issues" (full loop)
Responsive layout check β€” "Screenshot this page at 320px, 768px, and 1440px widths and verify the layout is correct"
Accessibility audit β€” "Check this page for missing alt text, heading hierarchy, keyboard nav, and color contrast issues"
23

Checkpoints & Session Forking

What: VS Code auto-snapshots your workspace before each agent action. Restore to any previous state, redo undone changes, edit & resend earlier prompts, or fork a conversation to explore an alternative approach β€” all without losing work.
CHECKPOINT TIMELINE β€” SNAPSHOT Β· RESTORE Β· FORK C1 Agent edits πŸ“Έ auto-saved C2 More edits πŸ“Έ auto-saved C3 ❌ Bad result πŸ“Έ auto-saved πŸ”„ Restore to C2 C4 New attempt βœ… better result F1 🍴 Fork Alternative approach ACTIONS πŸ”„ Restore 🍴 Fork ✏️ Edit & Resend
Checkpoints
  • Enable: chat.checkpoints.enabled
  • Auto-created before each chat request
  • Hover chat request β†’ Restore Checkpoint
  • Reverts all file changes made after that point
  • Redo button appears after restore β€” undo mistakes
View File Changes
  • Enable: chat.checkpoints.showFileChanges
  • Shows modified files + lines added/removed per request
  • Helps decide which checkpoint to restore to
πŸ’‘ Checkpoints complement Git but don't replace it. They're for quick iteration within a session β€” use Git for permanent version control.
Edit Previous Requests
  • Click any previous chat request to edit it
  • Reverts changes from that request + all later ones
  • Resends as a new request with your edits
  • Configure: chat.editRequests
Fork from Checkpoint
  • Hover chat request β†’ Fork Conversation
  • Creates new independent session from that point
  • Original conversation preserved
  • Explore alternative approaches side by side
Workflow
Agent Acts β†’ Review Output β†’ βœ… Keep / πŸ”„ Restore / 🍴 Fork
Use Cases
Safe experimentation β€” let the agent try a risky refactor, restore checkpoint if it breaks tests, fork to try an alternative
Prompt refinement β€” edit a vague prompt 3 requests back β†’ agent re-runs with better instructions, previous bad output is undone
24

Agent Sessions, Handoffs & Orchestration

What: Run multiple agent sessions in parallel across local, background (CLI), and cloud environments. Hand off tasks between agent types with full context carry-over. Manage everything from a unified sessions view.
MULTI-AGENT ORCHESTRATION β€” HANDOFF & PARALLEL HANDOFF FLOW (sequential with context carry-over) πŸ“‹ Plan (Local) VS Code interactive ⌨️ Build (CLI) Background on machine ☁️ PR (Cloud) Remote infra πŸ‘€ Review Team reviews PR PARALLEL AGENTS πŸ“‹ Task "Review this code for security" 🧠 GPT-5.4 🧠 Sonnet 4.6 🧠 Gemini 3.1 Pro ↓ compare results ↓ Full context carries over on handoff Β· Parallel agents run same task with different models or research different topics simultaneously
Agent Types
TypeRunsBest For
LocalVS Code (interactive)Brainstorm, debug, browse
Copilot CLIBackground on machineWell-defined tasks, POCs
CloudRemote infraPRs, team collaboration
Third-partyClaude / CodexProvider-specific models
Handoff Flow
Plan (Local) β†’ Implement (CLI) β†’ PR (Cloud) β†’ Review
  • Select different agent type from session dropdown
  • Full conversation history carries over
  • Original session archived after handoff
  • /delegate in CLI β†’ sends to cloud agent
Sessions View
  • Unified list of all sessions (local, CLI, cloud)
  • Compact or Side-by-side layout modes
  • Shows status, type, and file change stats
  • Archive / unarchive completed sessions
  • Grouped by time (Today, Last Week, etc.)
Agent Status Indicator
  • Badge in command center title bar Experimental
  • Shows unread messages + in-progress count
  • Enable: chat.agentsControl.enabled
Parallel Sessions
  • Create multiple sessions via + button
  • Each session: independent context window
  • Run different tasks simultaneously
  • Assign TODOs: right-click code β†’ assign to agent
Use Cases
Plan β†’ Build β†’ Ship β€” Plan agent designs architecture, hand off to CLI for implementation, then cloud agent opens the PR for team review
Parallel features β€” run 3 local sessions: one for API endpoints, one for UI components, one for tests β€” all working simultaneously
TODO delegation β€” add // TODO: add input validation in code β†’ right-click β†’ assign to Copilot coding agent β†’ agent creates a PR
25

Prompt & Context Engineering

What: Proven techniques for writing effective prompts and providing the right context. The quality of Copilot's output depends directly on how well you communicate β€” be specific, break tasks down, include expected output, and choose the right interaction mode.
GOOD vs BAD PROMPTS β€” QUALITY IN = QUALITY OUT ❌ BAD "Make this code better" Vague Β· No language Β· No criteria Β· No expected output β†’ poor results βœ… GOOD "Refactor to reduce O(nΒ²) β†’ O(n log n). Add tests." Specific Β· Clear goal Β· Measurable criteria Β· Includes verification step β†’ great results PROMPT ENGINEERING TIPS 🎯 Be specific language + framework + I/O βœ‚οΈ Break it down smaller steps = better πŸ“‹ Show expected test cases + criteria πŸ”„ Iterate refine with follow-ups ❓ Ask AI to ask clarify before coding πŸ“‚ Add context #file Β· #fetch Β· images 🧹 New sessions avoid context pollution PROMPTING TECHNIQUES 🧩 Few-Shot Prompting Provide 2-3 input β†’ output examples πŸ”— Chain-of-Thought "Think step by step before coding" 🎭 Role Prompting "Act as a senior security engineer" πŸ”€ Negative Prompting "Don't use regex. Don't use any libs." + more…
Writing Effective Prompts
  • Be specific β€” state language, framework, expected I/O
  • Break down complex tasks β€” smaller steps = better results
  • Include expected output β€” test cases, acceptance criteria
  • Avoid vague prompts β€” "make this better" β†’ "reduce time complexity"
  • Iterate with follow-ups β€” refine, don't rewrite the whole prompt
  • Ask AI to ask questions β€” "ask me clarifying questions before starting"
  • Course-correct early β€” steer mid-request if heading wrong way
Prompt Example
Write a TypeScript function that validates email addresses. Return true for valid, false otherwise. Don't use regex. Example: validateEmail("user@example.com") β†’ true Example: validateEmail("invalid") β†’ false
Providing Context
  • Agent auto-searches workspace β€” usually no need for #codebase
  • Reference specific files: #file, #folder, #symbol
  • #fetch β€” pull info from web pages / docs
  • Attach images / screenshots for visual context
  • Use integrated browser to select page elements
Pick the Right Mode
ModeWhen to Use
Inline suggestionsIn-flow coding, boilerplate
AskQuestions, brainstorm, explore
Inline chatTargeted in-place edits
AgentMulti-file autonomous changes
PlanArchitecture, migration strategy
Smart actionsOne-click commit msg, fix, rename
Session Hygiene
  • New session for unrelated tasks β€” avoid context pollution
  • Use subagents for isolated research
  • Run parallel sessions for independent work
Use Cases
High-quality output β€” "Implement a rate limiter using token bucket. Write tests that verify: 10 req/s allowed, 11th rejected, refills after 1s. Run the tests."
Plan first β€” use Plan agent to design architecture β†’ review β†’ hand off to Agent mode for implementation with tests as verification
26

Smart Actions

What: One-click AI-powered actions built into VS Code β€” no prompt needed. Generate commit messages, rename symbols intelligently, fix diagnostics, and search semantically. Available via right-click, lightbulb, or keyboard shortcuts.
SMART ACTIONS β€” ZERO PROMPTS NEEDED ✨ Commit Message F2 Smart Rename πŸ’‘ Fix with Copilot πŸ§ͺ Fix Test Failure πŸ“„ Generate Docs πŸ” Semantic Search πŸ“ PR Summary Access via ⌘. Β· Right-click Context menus
Available Actions
ActionWhere
Generate Commit MessageSource Control panel
Rename SymbolF2 on any symbol
Fix with CopilotLightbulb on errors/warnings
Fix Test FailureTest Explorer failed tests
Generate DocsRight-click β†’ Generate Code
Semantic SearchSearch view (meaning, not keywords)
Generate PR SummaryPR description field
How to Access
  • Lightbulb (⌘.) β€” hover over error β†’ AI fix suggestion
  • Right-click β†’ Generate Code menu
  • Context menus in Source Control, Test Explorer
  • No prompt required β€” Copilot infers from context
Use Cases
Instant commit messages β€” click ✨ in Source Control β†’ Copilot analyzes diff and generates a Conventional Commit message
Smart rename β€” F2 on processData β†’ Copilot suggests transformUserPayload based on function body semantics
27

BYOK β€” Bring Your Own Key

What: Use your own API keys to access hundreds of models beyond the built-in ones β€” including local models via Ollama or AI Toolkit. Bypass rate limits, experiment with cutting-edge models, and use your own compute.
BYOK β€” YOUR KEY Β· YOUR MODELS Β· YOUR COMPUTE πŸ”‘ Your API Key or local endpoint πŸ€– VS Code Manage Models AVAILABLE PROVIDERS OpenAI Anthropic Google Ollama (local) ⚠️ Pro/Pro+ only Β· Tool calling needed for Agent mode Β· No responsible AI filtering on BYOK output
Benefits
  • Model choice β€” access models not available built-in
  • Experimentation β€” try new models or features early
  • Local compute β€” run models on your machine (Ollama)
  • Greater control β€” bypass standard rate limits
How to Add
  • Model picker β†’ Manage Models β†’ Add Models
  • Select built-in provider or install extension
  • Enter API key / endpoint URL
  • Or: Chat: Manage Language Models command
Options
Built-in providersOpenAI, Anthropic, Google, etc.
ExtensionsAI Toolkit, Foundry Local
Local modelsOllama, custom OpenAI-compat
⚠️ BYOK is for Pro/Pro+ individual plans only. Not yet available for Business/Enterprise. Still requires Copilot service & internet for embeddings and indexing.
πŸ’‘ BYOK models need tool calling support to work in Agent mode. No responsible AI filtering on BYOK model output.
Use Cases
Run local Ollama β€” deploy Phi-4 locally, add via Manage Models β†’ use in chat with zero API cost and full privacy
Cutting-edge models β€” add your Anthropic key to try Claude's latest release before it appears in the built-in list
28

Privacy, Security & Trust

What: How GitHub protects your data β€” code is not used for training (Business/Enterprise), prompts are not retained, responsible AI filters run pre- and post-model, and IP indemnity covers Copilot-generated code.
Data Handling
WhatBehavior
Prompts & suggestionsNot retained after response delivered
Training on your codeNo (Business/Enterprise)
Telemetry opt-outIndividual users can opt out
Code snippetsEncrypted in transit & at rest
Responsible AI Filters
  • Pre-model β€” content exclusion, harmful prompt detection
  • Post-model β€” duplicate/public code detection, safety checks
  • Configurable: enable/disable public code matching
IP & Compliance
  • IP indemnity β€” GitHub indemnifies Copilot output (Business/Enterprise)
  • SOC 2 Type II compliant
  • GDPR compliant β€” EU data processing
  • Subprocessor list published on Trust Center
Security Best Practices
  • Review AI output for vulnerabilities (OWASP Top 10)
  • Don't paste credentials into prompts
  • Use content exclusion for sensitive files
  • Only use MCP servers from trusted sources
  • BYOK: no responsible AI filtering on output
πŸ’‘ Enable public code filter to block suggestions matching public repositories β€” reduces IP risk.
Use Cases
Compliance review β€” point stakeholders to the Trust Center FAQ for SOC 2, GDPR, and data handling evidence
Reduce IP risk β€” enable public code filter + content exclusion for proprietary algorithms β†’ dual protection
29

Org & Enterprise Administration

What: Admin controls for managing Copilot across your organization β€” assign seats, set policies for features & models, review usage analytics, audit logs, and configure content exclusions at scale.
POLICY CASCADE β€” ENTERPRISE β†’ ORG β†’ USER 🏒 Enterprise Top-level policies Β· Overrides all πŸ›οΈ Organization Seats Β· Models Β· Features Β· Exclusions πŸ‘€ User Personal prefs Β· Telemetry opt-out ADMIN TOOLS πŸ“Š Usage analytics πŸ“‹ Audit logs πŸ’° Premium request tracking CONFIGURABLE POLICIES Features Models Coding Agent Preview Features Public Code Filter Content Exclusion Seat Management 3rd-Party Agents
Policy Management
PolicyControls
FeaturesChat, completions, agents, MCP
ModelsEnable/disable premium models
Coding agentEnable cloud agent + 3rd-party
Editor previewOpt in to preview features
Public code filterBlock public code matches
Content exclusionExclude files/repos from AI
Access Management
  • Assign Copilot seats per user or team
  • Enterprise owners β†’ org-level access
  • Org owners β†’ member-level access
  • Policies cascade: Enterprise β†’ Org β†’ User
Usage Analytics
  • Dashboard: acceptance rates, active users, languages
  • Premium request consumption by user/team
  • Breakdown by feature (chat, completions, agent)
  • Export data via API for custom reporting
Audit Logs
  • Track Copilot actions by user
  • Seat assignments, policy changes
  • Available for Business & Enterprise plans
Settings Path
OrgSettings β†’ Copilot β†’ Policies / Models
EnterpriseEnterprise Settings β†’ Copilot β†’ Policies
πŸ’‘ Enterprise policies override org settings. If an explicit setting is chosen at enterprise level, orgs cannot change it.
Use Cases
Rollout strategy β€” enable Copilot for a pilot team, review usage analytics for 30 days, then expand to the full org
Model governance β€” disable Opus 4.6 (30Γ— cost) org-wide, allow only 0×–1Γ— models to control premium request spend
30

Subagents

What: Isolated child agents that run research or execution tasks within a parent agent session. Context stays separate to avoid polluting the main conversation β€” results are summarized back to the parent.
SUBAGENTS β€” SPAWN Β· RUN PARALLEL Β· SUMMARIZE πŸ€– Parent Agent Main conversation context preserved πŸ” Explore ⚑ Task πŸ“ Code-review πŸ”’ isolated πŸ”’ isolated πŸ”’ isolated πŸ“‹ Summary β†’ parent EXAMPLE USE CASES πŸ” 3Γ— Explore in parallel auth Β· caching Β· logging ⚑ Task runs test suite "2/47 failed" β†’ parent πŸ“ Review changes quietly no noisy output in chat
Built-in Subagents
SubagentPurpose
ExploreQuick codebase analysis & Q&A
TaskRun tests/builds, return brief summaries
Code-reviewReview changes, surface real issues
How They Work
  • Parent agent spawns subagent for a focused task
  • Subagent runs in isolated context β€” no pollution
  • Returns a single summary message to parent
  • Can run in parallel for independent tasks
  • Available in VS Code agent mode & Copilot CLI
When to Use
  • Research a topic without cluttering main chat
  • Run tests and get a pass/fail summary
  • Explore multiple approaches in parallel
Use Cases
Parallel research β€” agent spawns 3 Explore subagents to investigate auth, caching, and logging patterns simultaneously
Test runner β€” Task subagent runs full test suite, returns "2 of 47 tests failed: test_auth, test_cache" β€” no noisy output in main chat
πŸ“š Sources: VS Code Docs β€” Subagents
β˜…

Quick Reference & Resources

What: Essential keyboard shortcuts, AI-powered slash commands for creating customizations, and key links to documentation, changelogs, and community resources.
Chat Shortcuts
ShortcutAction
βŒƒβŒ˜I / Ctrl+Alt+IOpen Chat panel
⌘I / Ctrl+IInline chat
βŒ˜β‡§IToggle secondary sidebar
TabAccept suggestion
EscDismiss suggestion
Alt+] / Alt+[Next / prev suggestion
Ctrl+β†’Accept word by word
Useful Extensions
Awesome CopilotCurated tips & resources Β· β†— Link
Prompt BoostEnhance your prompts Β· β†— Link
Token TrackerTrack Copilot usage Β· β†— Link
SpecStorySave & search AI chat history Β· β†— Link
HuggingFaceHF models in VS Code Β· β†— Link
Quick Commands
CommandAction
/initGenerate workspace instructions
/create-agentAI-create a custom agent
/create-skillAI-create a skill
/create-promptAI-create a prompt file
/create-instructionAI-create an instruction
/create-hookAI-create a hook config
/hooksConfigure hooks menu
Key Resources
Feature MatrixCopilot feature comparison Β· β†— Link
MCP MarketplaceDiscover MCP servers Β· β†— Link
Skills RepositoryBrowse agent skills Β· β†— Link
ChangelogLatest Copilot updates Β· β†— Link
awesome-copilotCommunity resources Β· β†— Link
Use Cases
Fast navigation β€” memorize βŒƒβŒ˜I (open chat) + ⌘I (inline chat) + Tab (accept) for fluid keyboard-only workflow
Stay current β€” check github.blog/changelog/copilot weekly for new models, features, and API changes
πŸ“š Sources: GitHub Copilot Docs · Changelog