GitHub Copilot has evolved from inline code completion into a comprehensive agentic coding platform. The foundation is Copilot code completion, which provides real-time ghost text suggestions as developers type. Next Edit Suggestion (NES) proactively suggests the next likely edit based on recent patterns. Beyond completion, Copilot Chat introduces specialized chat participants prefixed with @, such as @workspace for codebase awareness, @terminal for shell commands, @github for repository search, and @vscode for editor-specific help. Slash commands like /explain, /fix, /tests, and /doc trigger specific actions without writing full prompts. References like #file and #selection explicitly include file contents or selected code as context.
Agent mode represents a step-change in capability: Copilot autonomously plans, writes code, runs terminal commands, fixes errors, and iterates to complete multi-step coding tasks, going beyond the conversational help provided by Chat. Copilot Coding Agent extends this into asynchronous operation: developers can assign a GitHub issue to Copilot, which then reads the issue, sets up its environment using a copilot-setup-steps.yml configuration file, explores the codebase, plans changes, implements code, runs tests in an iterative loop until they pass, and opens a pull request. The agent runs in an isolated cloud VM and supports multiple models including GPT-4o, Claude Sonnet, and Gemini.
Beyond Copilot, a diverse ecosystem of AI coding tools has emerged. Cursor is an AI-native IDE forked from VS Code offering deep codebase indexing and an Agent mode with multi-file editing through its Composer feature. Windsurf (formerly Codeium) provides an agentic Cascade flow that understands context and plans multi-step changes. Amazon Q Developer offers code transformation agents that upgrade Java applications autonomously, while Google's Gemini Code Assist provides multi-IDE support with cloud integration. Enterprise-focused options include Tabnine with local model support for privacy, while open-source alternatives like Cline, Aider, OpenHands, and SWE-Agent provide transparency and extensibility. Devin by Cognition operates as a fully autonomous AI software engineer in its own cloud environment, and Replit Agent builds applications through natural language conversation within the Replit IDE.