Install Claude Code: one command, four sticking points

Installing Claude Code is a single command, and it is not your problem. We measured it on 30 September 2026 in a freshly built Ubuntu 24.04 container: 16.6 seconds from the command to the finished message, exit code 0, version 2.1.285.

The short answer: run the native installer for your system, then open a NEW terminal window and check with claude --version. What actually holds people up comes after that, and it is four things: your PATH, the question of administrator rights on Windows, the Node version on the npm route, and the plan you need. Three of the four are answered incorrectly in the most widely read step-by-step guides.

How do you install Claude Code?

With one command that differs only by system. The native installer is the route Anthropic recommends, because it keeps itself up to date afterwards.

All five appear in Anthropic's setup documentation. One difference is worth knowing before you choose: a native installation updates itself in the background, Homebrew and WinGet do not. Installing through a package manager means updating by hand later with brew upgrade claude-code or winget upgrade Anthropic.ClaudeCode.

Two error messages on paste mean only that you are in the wrong shell. If Windows says The token '&&' is not a valid statement separator, you are in PowerShell and pasted the CMD command. If it says 'irm' is not recognized as an internal or external command, it is the other way round. Your prompt shows PS C:\ in PowerShell and C:\ without the PS in CMD.

What actually happens during the install?

One download, one file and one line in your shell configuration. We ran the documented command in an empty container and then looked at what was written to disk.

The install script itself is 9,704 bytes. It downloads a single binary of 240,327,864 bytes, roughly 229 MiB, and stores it at ~/.local/share/claude/versions/2.1.285, with a symlink pointing at it from ~/.local/bin/claude. The installer then writes one line into three files, .bashrc, .profile and .zshrc, and it is the same line every time:

. "$HOME/.local/bin/env"

That is the whole footprint. No system directories, no elevated rights, no background service. Which is exactly why the install does not take a minute.

Install duration, measured

One run per route on one machine. That is too little to rank the two routes against each other; what it shows is the order of magnitude. Both deliver the same binary.

Install duration, measured

Native installer	16.6 s
npm install -g	6.5 s

The point of these numbers is not which route is faster. The point is that the step most guides are built around finishes in under half a minute. The time goes somewhere else.

Why can your terminal not find claude afterwards?

Because your shell reads the line the installer wrote only when it next starts. This is the most common sticking point after a successful install, and it looks like a failure even though everything worked.

We reproduced it in the same run. A shell that has not read the configuration files reports:

$ command -v claude
claude: NOT FOUND

The same shell, after reading exactly the file the installer registered:

$ . "$HOME/.local/bin/env"
$ command -v claude
/root/.local/bin/claude

The file ~/.local/bin/env contains nothing more than a check for whether ~/.local/bin is already on the PATH, and prepends the directory if it is not. So the rule is: open a new terminal window after installing instead of carrying on in the old one. On Windows that means a new PowerShell or CMD window. If the message survives that, the install directory is not on your PATH, and Anthropic's PATH fix covers the rest.

Do you need administrator rights on Windows?

No. Anthropic's documentation states it plainly for the native Windows install: "You do not need to run as Administrator" (Anthropic, Advanced setup).

This is worth stating because widely read guides claim the opposite and have their readers start PowerShell as an administrator on purpose. The advice is not merely unnecessary, it creates a follow-on problem: an elevated PowerShell runs under a different user profile, the install then sits in a different home directory, and calling claude later from an ordinary window finds nothing. One unnecessary instruction produces a hunt for a fault that does not exist.

The second Windows decision is native or WSL, and the documentation gives a clear table:

Decide by where your projects sit. If you work in WSL anyway, install there with the Linux command and start claude there too, not from PowerShell. Git for Windows is optional on the native route and has exactly one consequence: without it, Claude Code runs shell commands through PowerShell; with it, through Git Bash.

curl or npm: does it make a difference?

Not to the file that ends up on your disk. We checked that rather than assuming it: we installed both routes in the same environment and compared the checksums.

$ sha256sum ~/.local/share/claude/versions/2.1.285
33dad1ec615a2e08cc78b494f05c110e49916de2c79d78ec8799ebf46b233d29

$ sha256sum .../claude-code-linux-x64/claude
33dad1ec615a2e08cc78b494f05c110e49916de2c79d78ec8799ebf46b233d29

Both files are 240,327,864 bytes and identical byte for byte, cmp reports no difference, and both print 2.1.285 (Claude Code). The npm route pulls the same native binary in through a per-platform optional dependency, and the installed binary does not itself invoke Node.

So the difference is not in what you get, it is in what you maintain afterwards:

The figure "Node.js 18 or higher", which appears in widely read guides, is out of date. On an older Node version the install does not actually break: npm prints an EBADENGINE warning, the install completes, and claude still runs, because the binary does not use your Node at runtime.

One thing the npm route gets wrong if you follow a common recommendation. Anthropic's documentation warns explicitly: "Do NOT use sudo npm install -g as this can lead to permission issues and security risks." That exact command appears as advice for Linux in step-by-step guides.

Which Anthropic plan do you need?

A paid one. The documentation is unambiguous here: Claude Code requires a Pro, Max, Team, Enterprise or Console account, and the free claude.ai plan does not include access to Claude Code. Finding that out after the install means the evening is already spent.

Signing in happens at first start: you run claude and follow the browser prompts. If the ANTHROPIC_API_KEY environment variable is set, Claude Code asks once to approve that key instead of opening a browser. Beyond that, Claude Code runs through Amazon Bedrock, Google Cloud and Microsoft Foundry.

What the usage costs you at the end of the month depends less on the plan than on how you work. The Claude Code cost calculator works that through with your own numbers.

How do you know the install holds?

Two commands, of which the second says more than the first. claude --version prints a version number such as 2.1.285 (Claude Code). That proves the file is found, and nothing else.

claude doctor checks the installation without starting a session and prints read-only diagnostics. From our run:

Running: native (2.1.285)
Platform: linux-x64
Path: /root/.local/share/claude/versions/2.1.285
Config install method: native
Search: OK (/usr/bin/rg)
Auto-update channel: latest
No installation issues found.

Three lines matter. Config install method shows which route installed it, which settles the question of two parallel installations at once. Search shows whether ripgrep is found, because without ripgrep the project search stops working. And Auto-updates shows whether you will keep getting current versions or are frozen where you are.

What if it still sticks?

Three cases cover most of it, and all three have a documented cause rather than a mystery.

claude still runs after uninstalling. Then a second installation exists, or an alias from an older installer. claude doctor shows in Path which file actually runs.

Alpine and other musl-based systems. The documented install command fails there with not found, because Alpine ships neither bash nor curl. The documentation lists bash and curl for the install plus libgcc, libstdc++ and ripgrep at runtime, then USE_BUILTIN_RIPGREP=0 in settings.json.

You want to know the binary is genuine. Every release publishes a manifest.json with SHA256 checksums, signed with an Anthropic GPG key. The fingerprint is 31DD DE24 DDFA B679 F42D 7BD2 BAA9 29FF 1A7E CACE. Installing through apt, dnf or apk gets you that check from the package manager automatically.

Do you get updates automatically?

That depends on which route you took above, and it is the one difference between the install routes that keeps affecting you. Native installations update in the background. Homebrew, WinGet and apt, dnf and apk do not, and need a command from you.

On a native installation you can also choose how quickly new versions reach you. The setting is autoUpdatesChannel and takes two values: latest, the default, gives you new versions as soon as they ship. stable gives you a version that is typically about a week old and skips releases with major regressions. If you use Claude Code for paid work and would rather not be surprised midweek, put this in your settings.json:

{
  "autoUpdatesChannel": "stable"
}

To apply an update immediately without waiting for the background check, run claude update. It reports either Successfully updated from <old> to version <new> or, when there is nothing to do, Claude Code is up to date. Which channel you are on, and when the last update was attempted, both show up in claude doctor.

What comes after the install?

The part that decides the outcome. An installed tool cannot yet know anything about your project, and the work that makes the difference is written down: what belongs in the CLAUDE.md, which rules you give the tool and which steps you keep for yourself.

How we run recurring procedures as versioned skills is in Claude Code Skills. If you want to work in German, Using Claude Code in German covers the answer language and the language of the project file. And how the tool compares with the editor most people try first is in Claude Code vs Cursor.