/icons/vscode-config.svg Copilot Custom Instructions

Overview

Configure GitHub Copilot to use custom instructions, reusable prompts, and project-specific guidelines. This setup allows you to tailor Copilot’s behavior to match your team’s coding standards, architecture patterns, and best practices.

What’s Included

Custom Instructions

• Instruction files enabled: Copilot automatically reads .github/instructions/*.instructions.md
• Instruction location: Configure where VS Code looks for instruction files
• Code generation context: Instructions are automatically added to relevant chat requests

Reusable Prompts

• Prompt files enabled: Create reusable prompts in .github/prompts/*.md
• Prompt location: Configurable prompt file directories
• Quick access: Reference prompts with #file syntax in chat

Agent Configuration

• AGENTS.md support: Use AGENTS.md in workspace root to define project context
• Automatic discovery: Copilot finds and uses agent definitions automatically

Commit & PR Generation

• Custom commit instructions: Add project-specific guidelines for commit messages
• PR description guidelines: Tailor pull request descriptions to your workflow
• Code review instructions: Customize how Copilot reviews your code selections

Setting Up Instructions

1. Create Instruction Files

Create .github/instructions/ directory in your workspace:

mkdir -p .github/instructions

2. Add Instruction Files

Example: .github/instructions/typescript.instructions.md

---
applyTo: "**/*.ts"
---

# TypeScript Standards

- Always use strict mode
- Prefer interfaces over types for object shapes
- Use explicit return types on functions
- No 'any' types without justification

3. Create Reusable Prompts

Example: .github/prompts/test-generation.md

Generate comprehensive unit tests for the selected code including:
- Happy path scenarios
- Edge cases
- Error handling
- Mock external dependencies

Usage Tips

1. Scope instructions: Use applyTo frontmatter to target specific files
2. Team consistency: Commit instruction files to version control
3. Prompt library: Build a library of reusable prompts for common tasks
4. Review customization: Add code review criteria specific to your project

Example Instruction Categories

• Code style: Formatting, naming conventions, import order
• Architecture: Component structure, state management patterns
• Testing: Test coverage requirements, testing libraries
• Documentation: JSDoc standards, README templates
• Security: Authentication patterns, data validation

Best For

• Teams with established coding standards
• Projects with specific architectural patterns
• Organizations with compliance requirements
• Developers who want consistent AI behavior across projects

{
  "github.copilot.chat.codeGeneration.useInstructionFiles": true,
  "chat.instructionsFilesLocations": {
    ".github/instructions": true
  },
  "chat.promptFiles": true,
  "chat.promptFilesLocations": {
    ".github/prompts": true
  },
  "chat.useAgentsMdFile": true,
  "github.copilot.chat.commitMessageGeneration.instructions": [],
  "github.copilot.chat.pullRequestDescriptionGeneration.instructions": [],
  "github.copilot.chat.reviewSelection.enabled": true,
  "github.copilot.chat.reviewSelection.instructions": []
}