What Claude Code actually is
Claude Code is Anthropic's command-line tool for software engineering tasks. It runs in your terminal, reads your project files, and takes instructions in plain text. You describe what you want done — refactor this function, add a test, fix this bug — and Claude Code reads the relevant files, proposes changes, and applies them with your approval.
It is not an IDE plugin. It is not a chat window you paste code into. It is a process that runs alongside your editor and has direct access to your file system.
That distinction matters. Claude Code can read twenty files at once, trace a bug across modules, and write a diff that touches multiple files. A chat window cannot do that reliably.
Minimal install steps
You need Node.js 18+ and an Anthropic API key. That is the full dependency list.
npm install -g @anthropic-ai/claude-code
export ANTHROPIC_API_KEY=sk-ant-...
claude
Run claude in any project directory. It will read your project structure and wait for a prompt. The first run takes a few seconds longer as it indexes the directory.
Set ANTHROPIC_API_KEY in your shell profile so you don't have to export it every session.
What to try first
Start with a narrow task. Ask it to explain a function you didn't write. Ask it to add a docstring. Ask it to write a single unit test. Narrow tasks give you a feel for how it reads your code before you hand it a bigger job.
Once you are comfortable with how it responds, you can give it multi-file tasks: "refactor the auth module to use the new token schema in config.ts."
What a daily workflow looks like
Most engineers use Claude Code in short bursts, not long sessions. You open the terminal, describe a task, review the diff, and move on. Sessions rarely last more than a few minutes.
A practical pattern: keep a CLAUDE.md file in your project root. Write down the conventions Claude Code should follow — naming patterns, which directories to avoid, any libraries it should prefer. Claude Code reads this file automatically at startup, so you don't have to repeat yourself every session.
When it saves the most time
Claude Code is fastest on tasks where you know what you want but the execution is mechanical: writing tests for an existing function, renaming a variable across a large codebase, generating boilerplate that follows an existing pattern. These tasks take five minutes manually and thirty seconds with Claude Code.
It is slower — and requires more review — on tasks where the design is unclear. If you don't know the right approach yet, Claude Code will pick one, and it may not be the one you would have chosen.
One step to take right now
Install Claude Code, open a project you are already working on, and ask it to explain the most complex function in the codebase. You will immediately see how it reads context and whether its understanding matches yours. That tells you where it is useful and where you still need to drive.
