Let's Create a GitHub Copilot Extension!

GitHub Copilot is a coding assistant and pair programming buddy that can perform inline code completions and has chat capabilities. It can be extended by GitHub Copilot extensions.

There are two types of GitHub Copilot extensions: skill set and agent. The skill set connects third-party services and custom APIs, while the agent allows complete control over request and response generation and enables custom workflows.

To create a GitHub Copilot extension, you need a publicly accessible web application or endpoint and a registered GitHub application. You configure the GitHub app for Copilot use and set minimal permissions.

GitHub Copilot extensions can be used anywhere GitHub Copilot is available, such as in Visual Studio Code, GitHub.com, JetBrains IDEs, Xcode, Vim, NeoVim, and even on the command line.

A GitHub app is essential for Copilot extensions as it provides authentication and authorization for accessing Copilot chat and editor context. It must be configured with the necessary permissions for the extension to function.

To use a GitHub Copilot extension, you need to give read-only access to Copilot chat and optionally, read-only access to editor context if you want to read files or have editor context.

Yes, GitHub Copilot extensions can work with any editor that leverages the Copilot language server SDK, including Microsoft development environments like GitHub.com, Visual Studio, and Visual Studio Code.

The Copilot extension preview SDK simplifies the process of building a Copilot extension as an agent. It provides security and response formatting utilities, handling request payload verification, parsing, and response building.

To run a GitHub Copilot extension locally, you need a Node.js environment, a public-facing endpoint, and the necessary GitHub app configuration with the appropriate permissions.