# The 7 files Copilot reads

> Most devs have never opened half of them. Here's what each one actually does — and why it matters.

- **Format:** short video, 9 steps, ~23 seconds
- **Topic:** A curiosity-driven walkthrough of the seven files GitHub Copilot actually reads out of a repo before suggesting anything, staged as a real VS Code Explorer sidebar with one moving tooltip that relabels itself per file: repo-wide instructions, path-scoped instructions, reusable agent skills, custom agents, the coding-agent setup workflow, workspace settings and MCP server config
- **Author:** Suthahar Jegatheesan (MSDEVBUILD)
- **Category:** GitHub Copilot · copilot
- **Published:** 2026-09-10
- **Tags:** githubcopilot, copilot, vscode, aiengineering, devtools, softwareengineering, promptengineering, msdevbuild
- **Canonical URL:** https://blog.msdevbuild.com/shorts/copilot-project-structure/

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## What you'll learn

- copilot-instructions.md is auto-attached to every chat request — repo-wide, no reference needed
- instructions/*.instructions.md scopes rules per path, skills/SKILL.md loads itself when your ask matches, and agents/*.agent.md (formerly chat modes) packages personas per task
- mcp.json and copilot-setup-steps.yml extend Copilot into real tools and give the autonomous coding agent its own preinstalled sandbox

## Understand it one step at a time

### 1. Be honest — how many have you opened?

Copilot reads every one of these files before it suggests a single line. Let’s open them, one by one.

### 2. File 1: it never forgets the rules

copilot-instructions.md rides along on every request — the closest thing Copilot has to memory.

### 3. File 2: rules that know the file type

instructions/*.instructions.md scopes different rules to different paths with one glob.

### 4. File 3: skills that load themselves

SKILL.md bundles instructions, scripts and resources — Copilot pulls it in the moment your ask matches, no slash command required.

### 5. File 4: chat gets a persona

A custom agent packages its own tools, model and instructions into one dropdown option.

### 6. File 5: the agent's launchpad

copilot-setup-steps.yml preinstalls everything before the autonomous coding agent starts work.

### 7. File 6: flip the switches

settings.json turns Copilot features on or off, per workspace, without touching code.

### 8. File 7: it can touch real systems

mcp.json connects Copilot to your database, Jira or an internal API as callable tools.

### 9. That's the whole rulebook

Seven files, all versioned in your repo — nothing hidden inside the model.

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## The takeaway

**Now you know all seven**

Versioned, reviewable, yours to edit — that's Copilot's real rulebook.