GitHub Copilot offers several customization features that let you tailor its behavior to your workflow, your team's standards, and your project's needs. Use the tables below to find the right one for your use case.
Feature overview
This table shows what each customization feature is and where it lives.
| Feature | What it is | Filename and location |
|---|---|---|
| Custom instructions | Always-on context that automatically applies to every interaction within its defined scope | .github/copilot-instructions.md (repo-wide), .github/instructions/*.instructions.md (path-specific), AGENTS.md (third-party agents), or personal/org settings via UI on GitHub |
| Prompt files | Reusable, standalone prompt template with input variables | .github/prompts/*.prompt.md |
| カスタム・エージェント | Specialist persona with its own instructions, tool restrictions, and context | .github/agents/AGENT-NAME.md (repo), agents/AGENT-NAME.md in .github-private repo (org/enterprise), or user profile |
| サブエージェント | Separate agent spawned by the main agent to handle delegated work in an isolated context | N/A (runtime process, not a user-configured file) |
| Agent skills | Folder of instructions, scripts, and resources that Copilot loads when relevant to a task | .github/skills/<skill-name>/SKILL.md (project) or ~/.copilot/skills/<skill-name>/SKILL.md (personal) |
| MCP servers | Connection to external systems, APIs, and databases | mcp.json (path varies by IDE), repo settings on GitHub (コーディング エージェント), or mcp-servers property in カスタム エージェント configurations |
Usage comparison
This table helps you decide which customization feature to use.
| Feature | How to trigger | Best for | Example use cases |
|---|---|---|---|
| Custom instructions | Automatic | Standards, guidelines, or expectations that apply broadly across a context | Enforce coding standards, accessibility rules, review checklists |
| Prompt files | Manual: reference directly in chat or use the prompt file picker | Focused single tasks you run once with different inputs each time | Generate unit tests, run a code review checklist |
| カスタム・エージェント | Manual: select from the agent dropdown in your IDE, on GitHub, or in Copilot CLI | Projects or processes with distinct stages that need specialized capabilities or strict handoffs | React reviewer agent, read-only auditing agent |
| サブエージェント | Automatic, or reference a サブエージェント directly in your prompt | Complex subtasks that should run in isolation from the main agent | Codebase research, running test suites |
| Agent skills | Automatic: chosen by Copilot when relevant to your prompt | Multi-step workflows with bundled assets that should be loaded as needed | GitHub Actions failure debugging, deployment procedures, release note drafting |
| MCP servers | Automatic, or ask for a specific tool by name | Tasks that require access to external tools or real-time data | Manage issues and PRs (GitHub MCP server), automate browser testing (Playwright MCP server) |
IDE and surface support
This table shows which customization features are supported in each IDE and surface. For the full Copilot feature matrix, see Copilot 機能マトリックス.
GitHub recommends using the latest stable IDE, Copilot CLI, and Copilot extension versions to get the best Copilot experience.
Key:
- ✓ = supported
- ✗ = not supported
- P = under preview
| Feature | VS Code | Visual Studio | JetBrains IDEs | Eclipse | Xcode | GitHub.com | Copilot CLI |
|---|---|---|---|---|---|---|---|
| Custom instructions | ✓ | ✓ | P | P | P | ✓ | ✓ |
| Prompt files | ✓ | ✓ | P | ✗ | P | ✗ | ✓ |
| カスタム・エージェント | ✓ | ✗ | P | P | P | ✓ | ✓ |
| サブエージェント | ✓ | ✗ | P | P | P | ✗ | ✓ |
| Agent skills | ✓ | ✗ | P | ✗ | ✗ | ✓ | ✓ |
| MCP servers | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
For a detailed breakdown of which types of custom instructions are supported in each IDE and surface, see さまざまな種類のカスタム命令のサポート.
Further reading
- カスタマイズ ライブラリ—a curated collection of examples