The short answer
Claude Code is the coding agent from Anthropic, the company that makes the Claude models. You describe a task in plain language, and it reads your project’s code, edits files, runs commands and tests, and shows you what it changed. It runs in the terminal, in VS Code and JetBrains, in a desktop app and in the browser.
What sets it apart from a chatbot is that it acts on its own. ChatGPT gives you code to paste in yourself. Claude Code does the work inside your project, step by step, and asks before it does anything you haven’t allowed.
What Claude Code does
Give Claude Code a task like “add an export button to the invoice overview” and it breaks it into small steps. It finds the files involved, works out how the project fits together, writes the change, runs the tests and fixes whatever fails. You see every step as it happens and can redirect it at any point.
Reads your project
Claude Code finds the relevant files on its own. You don't copy code into it or explain where things live.
Edits files
It writes changes straight into your project, even when they span dozens of files. You see the diff for each file.
Runs commands and tests
It starts your test suite, the build or a script, reads the errors and keeps adjusting the code until it passes.
Works with Git
It can commit its changes and prepare a pull request, so the work lands in your normal review process.
Remembers your conventions
A CLAUDE.md file in your project holds the rules: which commands exist, which style you follow, what it must never touch. It reads that file every time it starts.
Claude Code is an example of an AI harness: the software around a language model that gives it tools, context and limits. What that means and why it matters so much is in what is an AI harness.
Claude Code, Cursor and ChatGPT compared
All three use a language model to write code. Where they differ is where you work and how much the tool does by itself.
| Claude Code | Cursor | ChatGPT | |
|---|---|---|---|
| What it is | A coding agent that carries out tasks in your project. | A code editor with AI built in, based on VS Code. | A general chat assistant that also writes code. |
| Where you use it | Terminal, VS Code, JetBrains, desktop app or browser. | Inside the editor. | In a chat window, separate from your project. |
| Sees your project | Yes, it looks up the files it needs. | Yes, the editor passes your project to the model as context. | Only what you paste or upload. |
| Acts on its own | Edits files, runs commands and tests, makes commits. | Completes code as you type, plus an agent mode for bigger tasks. | Writes code that you put into your project yourself. |
| Best for | Tasks that touch many files, and developers who hand off a task and review the result. | Developers who want to keep typing with AI alongside. | Explanations, small snippets and thinking a problem through. |
In practice the lines keep blurring. Cursor has an agent mode, and Claude Code runs as an extension inside your editor. The choice that remains: do you want to type with AI next to you, or hand off a task and judge the result? A wider look at the tools is in vibe coding tools, and which harness fits which situation is in the best AI harness for coding.
How a senior team works with Claude Code
We use Claude Code every day. The gap between good and bad results comes down to how you brief it and what you do with what it hands back.
Write the conventions down
A good CLAUDE.md names the test commands, the folder layout, the conventions and what is off limits. Every mistake the agent makes twice becomes a line in that file.
Plan first, code second
For anything sizeable, have Claude Code write a plan first. Read it, correct it, then let it build. A wrong plan costs a minute to fix. A wrong change across fifty files costs an afternoon.
Keep tasks small and well defined
One function, one bug, one page at a time. The smaller the task, the easier the change is to review.
Let tests check the work
An agent that can test its own work catches its own mistakes. Without tests you are taking its word for it, and that isn't enough.
Review every change
Everything Claude Code produces goes through review, like a colleague's work. Where security, payments or customer data are involved, a senior developer looks twice.
Claude Code makes an experienced developer much faster. An inexperienced one mostly gets faster at making mistakes.
That is no reason to avoid it. It means the judgement about the code has to stay with a person who knows where things go wrong. What that looks like across a whole project, from first setup to production, is in how to develop software with AI.
Where Claude Code is a weaker fit
Claude Code is built for people who can read code. Without that, you can’t tell whether a change is safe, and small mistakes pile up unnoticed. If you want to build something without programming knowledge, a prompt-to-app builder like Lovable or Bolt is the more natural place to start.
Very large or old codebases without tests also need more guidance. The agent can’t see at once how everything connects, and a change in one place can break something elsewhere. There it pays to get tests and a CLAUDE.md in order first.
Conclusion: a fast colleague you keep reviewing
Claude Code is the step from AI that suggests to AI that does the work. It reads your project, changes the code and tests what it wrote. With an experienced developer at the wheel, that saves a lot of time. What’s left is the work that takes experience: giving the right brief and judging what comes back.
Claude Code = execution
Tasks you hand to an agent inside your project, from a bug fix to a change across dozens of files.
Senior developer = judgement
The brief, the plan and the review. That is where quality comes from, and it stays with a person.
What is Claude Code?
What is the difference between Claude Code and Claude?
What is the difference between Claude Code and Cursor?
Is Claude Code free?
How do you install Claude Code?
Can you use Claude Code without knowing how to code?
Build faster with AI without lowering the bar?
Our senior developers work with Claude Code every day. Bring them onto your project, or have your team learn to use it well in a workshop.
