Allison outlines the upcoming deprecation of GitHub Copilot Extensions as GitHub moves toward the Model Context Protocol (MCP), offering guidance for developers on transitioning to this universal standard.

Deprecation of GitHub Copilot Extensions: Moving to MCP Servers

Author: Allison

What’s Changing

GitHub is officially deprecating Copilot Extensions (built as GitHub Apps) on November 10, 2025. Instead, the platform is adopting Model Context Protocol (MCP), an open standard designed for integrating AI agents across environments. This standard allows developers to build an MCP server once for compatibility with any MCP-capable agent, including GitHub Copilot and others.

Who Is Affected

  • Developers who have created or are using Copilot Extensions as GitHub Apps.
  • Unaffected:
    • Client-side VS Code Copilot Extensions (they remain fully supported)
    • Standard GitHub Apps without Copilot Extension features

Why This Change Matters

GitHub Copilot Extensions only work inside Copilot chat, which required developers to build platform-specific solutions. MCP introduces:

  • Universal, open integration standard
  • Modular, composable architecture
  • Cross-platform compatibility
  • Easier maintenance and improved performance

With MCP, developers can focus on building their tool once and using it across multiple AI assistant platforms.

Action Items for Developers

  • Existing Copilot Extensions:
    • Plan your replacement strategy. Extensions will stop working after November 10, 2025.
  • Hybrid Apps:
    • Disable the Copilot Extension config in your App settings before sunset if you want it to remain listed on the Marketplace.
  • Start with MCP:
  • No New Extensions:
    • Creation of new Copilot Extensions (server-side) is blocked after September 24, 2025.

Timeline of Key Dates

  • September 24, 2025: New Copilot Extension creation blocked
  • November 3–7, 2025: Brownout testing (temporary interruptions)
  • November 10, 2025: All Copilot Extensions (GitHub Apps) are disabled

Frequently Asked Questions

Why is GitHub making this change?

GitHub aims to unlock more ecosystem value and streamline development through MCP, allowing for greater compatibility and easier developer experience.

What happens after November 10, 2025?

  • Copilot Extension functionality will be fully disabled.
  • Marketplace:
    • Copilot Extension-only apps: removed
    • Hybrid apps: must disable Copilot Extension config to remain in Marketplace
    • @mentions of retired extensions will be treated as plain text; VS Code extensions remain available

Can I convert my Copilot Extension to a regular GitHub App?

If your app combines Copilot Extension and classic GitHub App features, only the GitHub App features continue after the sunset. Review your Marketplace settings before the deadline.

What about private/internal Copilot Extensions?

They follow the same sunset timeline.

How do I migrate to MCP?

Is there feature parity between Extensions and MCP?

Much functionality is replicated, but architectural differences exist, especially for agent-based scenarios.

Where can I get support?

Consult documentation and community forums. Guides address common MCP scenarios.

What about the Copilot Extensions Marketplace category?

It will be removed after November 10, 2025. Hybrid apps must disable their Extension configuration to stay listed as GitHub Apps.

How will users find MCP servers?

The GitHub MCP Registry acts as a global directory.

Will there be admin controls?

MCP supports organization-level enable/disable/allowlist policies, with gradual IDE rollout for per-server controls.

Summary

Developers should begin planning the move to MCP now for continued compatibility with Copilot and other AI assistants. GitHub Copilot’s plugin system is evolving to an open, industry-standard approach.

This post appeared first on “The GitHub Blog”. Read the entire article here