I've been watching the AI coding tools space evolve through three distinct stages, each happening faster than the last.

Stage 1: Copilot (2022)

GitHub Copilot, powered by OpenAI Codex, marked the beginning of smart autocomplete. It could finish your functions, handle boilerplate, and suggest common patterns — but you were still firmly in control.

It became wildly widespread once it was available as a VS Code extension. That easy integration made it instantly accessible to millions of developers already using VS Code daily. No new tool to learn, no configuration overhead — just install and go.

Its low-friction setup, combined with real-time productivity gains, made it sticky. Developers could see value within seconds: less typing, fewer context switches, and suggestions that often felt magical. That combination of accessibility, immediacy, and familiarity is what truly launched the Copilot era.

Stage 2: Agentic IDEs (2024)

The game changed when Cursor introduced Agent Mode. It transformed the IDE into an agent capable of reading your entire codebase, making multi-file edits, running terminal commands, executing tests, and reasoning across projects.

No more manual orchestration—Cursor itself could manage your development workflow.

Others, like Windsurf's Cascade agent, followed and soon after got sold to OpenAI for $3B.

Still, this intelligence was constrained inside the IDE. You needed to stay within that sandbox.

Stage 3: Claude Code (2025)

Claude Code works as both a VS Code extension and a command-line tool. You can pipe files to it, chain it with other commands, or integrate it directly into existing workflows.

It’s not confined to a single environment—it becomes part of your existing toolkit. One of its most impressive features is the ability to spin up subagents, where Claude Code uses its own CLI to launch additional agent instances.