How to Get Started With Claude Code in 2026

Getting Claude Code to produce something is easy. You type a request, it reads some files, and code appears. The harder part starts a few days later, when you have to decide how much it should do unasked, why a good session went strange after lunch, and how you know the work is finished and not just fluent.

This is a practical way to start. It skips the feature tour and gives you the handful of habits that make the first week go well. It describes Claude Code as it stood in October 2026. The tool moves quickly, but the habits here move slowly, which is why they are worth learning first.

Know the loop it runs

Claude Code appeared as a research preview in February 2025 and reached general availability in May 2025. By late 2026 it is less a single tool than a set of doors onto the same agent: the command line, a desktop app, the web, IDE extensions, mobile, Slack, a Chrome extension and GitHub Actions. Start in the terminal. The other doors make more sense once you have used that one.

Whichever door you use, every session runs the same loop. It gathers context, takes an action, verifies the result, and repeats until the task is done or it needs something from you.

That sounds too simple to matter. It matters because it tells you where to look when a session goes wrong. Either it gathered the wrong context, took the wrong action, or did not verify. Until you can see the loop, the agent looks like a magician, and magicians are hard to correct.

It also helps to hold the right picture of what you are working with.

An agent is not a smarter keyboard. It is a colleague who never tires and occasionally misunderstands.

Autocomplete finishes your line. An agent finishes your task. That means the skill you need is closer to delegation than to typing.

Your first five minutes

Pick a repository you know reasonably well. Not the most important one in the company, and not a toy you made last night. Something in between, where you would recognise a wrong answer. Open a terminal there and type claude.

For the first session, ask for something small and real. A good first task has three properties: you could do it yourself, you would know if it were done badly, and nothing serious breaks if it is.

Then read the diff. All of it. This is the step people skip, and it is the one that teaches you how the agent thinks, what it notices and what it assumes.

The first diff you approve teaches you more than the first ten you skim.

If you get nothing else from your first day, get that habit.

Say what done looks like

Most bad sessions begin with a good intention and a bad sentence. "Fix the login thing." "Make the dashboard nicer." "Tidy up the API." Each of these is a wish, and a wish has no edges. The agent is diligent, so it will find some edges for you. They will not be the ones you meant.

A task has edges. Before you press Enter, check that your request says:

• what should be different when the work is finished
• what must be left alone
• how either of you will know it worked

One clear sentence written before the code is usually the cheapest fix available.

For anything larger than a small change, ask for a plan first. Claude Code has a planning mode for exactly this. The agent reads, thinks and proposes, and nothing is edited until you agree. The expensive mistakes in software tend to be made in the first five minutes, before a line is written. A plan is where you catch them, and reading one takes a minute.

Decide how much rope to give

Sooner or later you face the permissions question: how much should the agent be allowed to do without asking? The useful answer has little to do with how clever the model is. It depends on what happens if it is wrong. A wrong edit to a file under version control is a small mess. A wrong command against a production database is not. Let it run freely where mistakes are cheap and keep your hand on the brake where they are not.

Three things make this easier than it sounds.

There is an undo. Every edit Claude Code makes is snapshotted as a checkpoint, and you can go back. Knowing that makes it much easier to let the agent try things.

You can interrupt. Watching an agent work is a little like watching someone parallel park your car. Mostly fine, and occasionally you see the bollard before they do. Press Esc to stop it and say, in one sentence, what you want instead. Steering early costs a sentence. Steering late costs a rewrite.

Instructions fade, arrangements hold. Anything you tell the agent in plain English is a request. It is usually honoured. But sessions run long, context fills up, early instructions get summarised, and a careful rule can become a vague memory of a rule. For the things that must always happen, such as running the formatter after an edit or never touching a certain folder, Claude Code has hooks: small pieces of your own code that run at fixed moments in the session whether anyone remembers or not.

Instructions are what you hope will happen. Hooks are what you have arranged.

You do not need hooks in week one. You do need to know they exist, so that the first time a rule is forgotten you know where the proper fix lives.

Give it a memory and make it prove its work

Every session begins as a stranger. It arrives clever, well read and entirely ignorant of your project. It does not know that the tests take four minutes, which dev command is the right one here, or that nobody touches the legacy/ folder without a good reason. You could tell it every morning. You will tire of that by Wednesday.

The answer is a file called CLAUDE.md, which Claude Code reads at the start of each session. Think of it as a letter to someone arriving cold. Keep it short. Put in the commands that work, the conventions that matter and the places not to touch. There are several layers of this file, some personal and some shared with a team, but one at the root of the project is enough to begin with.

Memory has a cost, though. Everything the agent knows about your task at a given moment sits in a context window: the instructions, the files it has read, the output of every command, your messages. On supported models that window is very large, up to a million tokens. Large is not the same as infinite, and a cluttered window makes for a cluttered mind. When you change subject, start fresh. A window full of yesterday's logs has no room for today's problem.

Finally, do not accept "done" as a statement. An agent that says it has finished is offering an opinion. An agent that has run the tests and watched them pass is offering evidence. Give it a way to check itself, whether that is a test suite, a build or a command whose output shows the result, and ask it to use it before it reports back. If it cannot check its own work, you will be checking it for ever.

A first-week checklist

1. Start in the terminal, in a repository where you would recognise a wrong answer.
2. Give it one small, real task and read the whole diff.
3. Write requests with edges: what changes, what stays, how you will know.
4. Ask for a plan before any change you could not review in one sitting.
5. Give more freedom where mistakes are cheap and less where they are not.
6. Write a short CLAUDE.md so tomorrow's session does not start from nothing.
7. Start a fresh session when the subject changes.
8. Ask for evidence that the work is finished, not a sentence saying so.

The agent supplies the effort and you supply the reasons. Delegate the work and keep the judgement.

If you want the long version, I wrote it as Claude Code: The Ultimate Guide 2026: a hundred short chapters across ten parts, from the first session through memory, skills, hooks, MCP servers, subagents and team rollout, each with a detailed diagram. It is an independent guide, not affiliated with or endorsed by Anthropic. It costs £9 on Gumroad with a 30-day refund: matsiems.gumroad.com/l/claude-code-ultimate-guide-2026. You can also read it free online at matsiems.com/books/claude-code-ultimate-guide-2026.