Why This Matters

MCP (Model Context Protocol) is the underlying protocol for tools Copilot can call. Understanding it unlocks custom tooling without building full Extensions.

Concept Explained

MCP is a protocol for exposing tools to AI models. An MCP server provides tools (functions Copilot can call); Copilot invokes them when relevant. Like Extensions, but more flexible and often local.

How It Works

Run an MCP server (locally or remote). Configure Copilot to connect to it. Copilot can now invoke the server's tools when relevant to your question.

Step-by-Step Tutorial

1. Understand MCP

2. Run a server locally

3. Configure Copilot

4. Use

5. Distinguish from Extensions

Real-World Example

A developer ran a local MCP server exposing their team's internal API. Asked Copilot 'what's the status of deploy #142?' — Copilot invoked the MCP tool, fetched live data, answered. No full Extension build needed.

Example Prompts / Commands / Code

# In VS Code settings (or .mcp.json):
{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/allowed/dir"]
    },
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": { "GITHUB_TOKEN": "YOUR_GITHUB_TOKEN" }
    }
  }
}

Feature            Extensions              MCP servers
-----------------------------------------------------------
Build effort       High (manifest, host)   Low (run a server)
Hosting            Cloud                   Local or remote
Use case           Production, shared       Personal, team
Customization      Code changes             Config changes
Best for           Org-wide tools           Personal/team workflows

Common Mistakes

• Confusing MCP with Extensions — they're related but different.
• Running untrusted MCP servers — security risk.
• Exposing too much filesystem access — security risk.
• Not understanding the protocol before adopting.

Best Practices

• Start with well-known open-source MCP servers.
• Run locally first; production later (see PR-26).
• Limit filesystem and API access scopes.
• Use MCP for personal/team workflows; Extensions for org-wide.
• Understand the protocol before adopting.

Troubleshooting

Practical Exercise

Professional Challenge

Frequently Asked Questions

Further Reading

• MCP documentation

Official References

• MCP docs

Related lessons: IN-35, PR-26