The ability to customize and extend Copilot is one of the most rapid areas of change. Copilot currently supports the addition of custom models and custom applications and the addition of functionality through VS Code Extensions. Introduced in November 2024, the Model Context Protocol (MCP) provides a standardized way of connecting large language models (LLMs) together, and as tools and vendors standardize on this protocol, the ability to plug new functionality into Copilot is increasing rapidly.