1-2 What's the Difference Between AI Coding Assistants and AI Coding Agents?

In this section, we'll explore the key differences between AI Coding Assistants and AI Coding Agents.

The Evolution of AI Coding Assistants

When people think of AI coding assistants, GitHub Copilot usually comes to mind first. GitHub Copilot launched in November 2021 with just autocomplete functionality. Even that simple feature was a game-changer for developers because it automated all those tedious bits of code you'd normally type by hand.

By 2023, GitHub Copilot added Chat functionality. This let developers use ChatGPT and other AI models directly in their IDE. When you hit a problem, you could ask the AI right there in your editor and get answers instantly.

With AI coding assistants, here's how refactoring typically works:

• You manually hunt through your codebase to find similar code patterns
• You copy-paste them into ChatGPT or GitHub Copilot and ask the AI to extract reusable functions
• If there's no test coverage, you ask ChatGPT or GitHub Copilot to write tests first
• You go to different files and ask the AI to refactor each one using the extracted functions
• Finally, you run tests to make sure everything works (if not, you go back and fix things)

This was revolutionary at the time. Many developers stopped relying on Stack Overflow or Google searches because they could just ask their AI assistant directly in the chat window. But now we're entering a new era: AI agents.

What Makes AI Coding Agents Different

Starting in 2025, AI development entered the AI agent era. We've previously written about What are AI agents and how can engineers leverage them? - worth a read if you want to dive deeper.

The core concept of AI agents is simple: they complete tasks toward a specified goal without human intervention.

With AI agents, coding becomes much more efficient because the agent will:

• You point to some code that needs refactoring and tell the AI agent: "There's a lot of similar but not identical code in this codebase. Please refactor to eliminate duplication."
• The AI agent scans through your entire codebase and identifies all similar patterns
• It extracts the duplicate parts into reusable functions or methods
• It ensures there are tests and adds any missing ones
• It runs the tests in the terminal based on the refactored code and tests
• If tests fail, it goes back and fixes the extracted common functions
• It repeats this process until all tests pass

This might sound abstract in text, so we encourage you to try Cursor; the benefits of an AI agent will become clear right away.

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