# How to extend GitHub Copilot with prompt files

> Because copy-pasting prompts from your notes app is so last year. Let me show you how to turn your best prompts into reusable superpowers.

- Published: 2025-09-10
- Author: Sven Scharmentke
- Canonical: https://svnscha.de/posts/howto-extend-copilot-with-prompt-files/
- Tags: copilot, prompt-engineering, vscode, productivity, ai

---

## Why, You Ask?

Remember when I went absolutely euphoric about [vibe coding](/posts/vscode-vibe-coding/)? Well, that honeymoon phase taught me one crucial lesson: **context matters, and you really need to spend time writing good prompts.**

At first, I was frantically scribbling prompts in my notes app like some kind of digital hoarder. Then I graduated to GitHub Copilot instruction files, adding rules like "when asked for review, do this and that." But constantly switching between apps and copy-pasting prompts? **I'm tired of it.**

GitHub Copilot's prompt files solve this by keeping reusable instructions in the repository.

## Using `.prompt.md` Files

Prompt files turn your best prompts into reusable slash commands. VS Code gives you two flavors:

- **Workspace prompts** (`.github/prompts/`): Travel with your repository, perfect for team-shared helpers
- **User prompts**: Stored in your VS Code profile, available everywhere for personal tools

Both become accessible as `/my-prompt` directly in VS Code chat. Instead of hunting through notes for that brilliant review prompt, you just type `/svnscha-blog-review` and boom, there it is.

**Note:** Prompt files are currently in public preview and may change in future releases.

## Real-World Example: Blog Review Prompt

Let me show you what this looks like in practice. I use project prefixes for workspace prompts and `/my-...` for personal ones.

For this blog, I created `/svnscha-blog-review` - a specialized prompt that understands my writing style:

```markdown
---
mode: "agent"
description: "Review blog posts for svnscha.github.io with focus on style, grammar, and technical accuracy"
---

# Blog Post Review for svnscha.github.io

You are an expert editor reviewing a blog post for svnscha's technical blog.

Focus on:

## Writing Style & Tone

- Consider using "Why, You Ask?" openings when it makes sense for the topic (not mandatory for all posts)
- Keep the direct, slightly sarcastic but helpful voice
- Ensure smooth transitions between sections
- End posts with a short summary or practical next steps when they add value

## Technical Accuracy

- Verify code examples are correct and practical
- Check that technical explanations are clear and accurate
- Ensure all file paths and commands are properly formatted

## Grammar & Spelling

- Fix any grammatical errors or typos
- Improve sentence structure where needed
- Maintain consistency in technical terminology

## Content Structure

- Ensure headings flow logically
- Verify examples support the main points
- Suggest a brief summary or actionable next steps when appropriate
- Check that the conclusion ties back to the opening

Provide specific, actionable feedback that maintains the author's voice while improving clarity and correctness.
```

This becomes available as `/svnscha-blog-review` in VS Code, giving me instant access to a specialized editor that knows my style.

## Smart Naming & Location Strategy

The naming convention is simple: **project prefixes for workspace prompts, `/my-...` for personal ones.** So `/svnscha-blog-review` is specific to this blog, while `/my-commit` works everywhere.

Choose your location based on scope:

- **Workspace prompts**: Team-shared, project-specific helpers
- **User prompts**: Personal tools that follow you across all projects

## Dynamic Prompts with Variables

Make your prompts adapt to context with VS Code variables:

```markdown
# Code Review Prompt

Review the following code in ${file}:

${selection}

Focus on:
- Security vulnerabilities in ${fileBasename}
- Performance implications 
- Code style consistency with ${workspaceFolderBasename} standards
```

The most useful variables include:

- **Workspace**: `${workspaceFolder}`, `${workspaceFolderBasename}`
- **File context**: `${file}`, `${fileBasename}`, `${fileDirname}`
- **Selection**: `${selection}`, `${selectedText}`

For the full list of available variables and advanced features, check out the [VS Code prompt files documentation](https://code.visualstudio.com/docs/copilot/customization/prompt-files).

## Setting Up Your Prompt Arsenal

Getting started is simple:

### Workspace Prompts

1. Create `.github/prompts/` in your repository
2. Add your `.prompt.md` files
3. Commit and push - your team now has access

### User Prompts

1. Open Command Palette (`Ctrl+Shift+P`)
2. Run "Chat: New Prompt File"
3. Choose "User profile" for location
4. Author and save your prompt

Both methods make prompts available with `/prompt-name` in GitHub Copilot chat. Workspace prompts travel with your repository, while user prompts sync across devices with Settings Sync.

For examples and community contributions, check out the [Awesome GitHub Copilot prompts collection](https://github.com/github/awesome-copilot/tree/main/prompts).

## Summary

Prompt files transform good prompting from an exclusive skill into a shared superpower. Your team gets expert-level guidance, your hotfix deployments get proper review, and your collective wisdom becomes instantly accessible with slash commands.

## Next Steps

1. **Start small** - Convert your three most-used prompts to `.prompt.md` files
2. **Choose scope wisely** - Workspace prompts for teams, user prompts for personal tools
3. **Use variables** - Make prompts dynamic with `${selection}`, `${file}`, and `${input:variableName}`
4. **Follow naming conventions** - Project prefixes for workspace, `/my-...` for user prompts
5. **Explore the community** - Check out [Awesome GitHub Copilot prompts](https://github.com/github/awesome-copilot/tree/main/prompts)
6. **Read the docs** - [VS Code prompt files documentation](https://code.visualstudio.com/docs/copilot/customization/prompt-files) has the latest features

The main benefit is simple: useful instructions live with the project and can be reused without copying them into every chat.