Installing Claude on Ubuntu Virtual Machines

This guide addresses a common installation issue when installing Claude Code on Ubuntu cloud instances (for example, Amazon EC2 or Lightsail). It explains why a global npm install can fail with permission errors and shows a reliable workaround using Claude’s native installer that installs to a user-local directory. Start from a typical Ubuntu shell prompt:

ubuntu@ip-172-26-8-154:~$

Update and upgrade the system

Always start by updating package lists and installing available upgrades:

sudo apt update
sudo apt upgrade -y

Example output you might see:

Fetched 36.9 MB in 12s (3002 kB/s)
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
24 packages can be upgraded. Run 'apt list --upgradable' to see them.

If a kernel upgrade is included, the system may warn that a reboot is required to load the new kernel:

Pending kernel upgrade!
Running kernel version:
    6.14.0-1010-aws
Diagnostics:
    The currently running kernel version is not the expected kernel version 6.14.0-1012-aws.

Restarting the system to load the new kernel will not be handled automatically, so you should consider rebooting.

If you see such a message, schedule or perform a reboot so the new kernel is active before proceeding.

Why global npm install can fail (EACCES permissions)

The Claude Code docs provide an npm-based install command:

npm install -g @anthropic-ai/claude-code

On many cloud images, running that command as a non-root user produces an EACCES error because the default global npm directory (commonly /usr/local/lib/node_modules) is owned by root:

npm ERR! code EACCES
npm ERR! syscall mkdir
npm ERR! path /usr/local/lib/node_modules
npm ERR! errno -13
npm ERR! Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules'
...
npm ERR! The operation was rejected by your operating system.
npm ERR! It is likely you do not have the permissions to access this file as the current user

Anthropic recommends not using sudo npm install -g ... for their package. Instead, prefer one of the safer alternatives below.

Anthropic’s documentation warns against running sudo npm install -g .... Use a user-local npm prefix, change ownership only if appropriate, or use the native installer that places the binary in ~/.local/bin.

Options to resolve the EACCES error:

Option	When to use	Command(s)
Install globals in a user directory	Best for single-user environments	`mkdir -p ~/.local/lib ~/.local/bin` `npm config set prefix "$HOME/.local"` `export PATH="$HOME/.local/bin:$PATH"` (persist in `~/.profile` or `~/.bashrc`)
Change ownership of global folder	Use only on controlled systems where you manage users	`sudo chown -R $(whoami) /usr/local/lib/node_modules`
Use the Claude native installer	Recommended to avoid npm-global issues completely	See step 4 below (installer places `claude` in `~/.local/bin`)

System requirements — choose an instance with at least 4 GiB RAM

Claude Code’s documentation lists system requirements; in practice you should provision an instance with at least 4 GiB of RAM and adequate CPU and disk for your workflows. If you’re using Lightsail, select a plan that meets those minimums.

A screenshot of a web documentation page from Anthropic titled "Set up Claude Code," showing system requirements and installation notes with a left navigation menu. The browser window is over an Amazon Lightsail page visible in the background.

If you use Amazon Lightsail or a similar provider, pick a plan that matches the memory/CPU needs — for example, a plan with 4 GiB RAM.

A screenshot of the Amazon Lightsail instance selection page showing network type choices and a grid of pricing tiers from 5 to 384 per month, with the $24/month plan highlighted. Each plan card lists memory, vCPUs, SSD storage, and transfer allowances.

Install the native Claude Code binary (recommended)

The easiest and most reliable method that avoids global npm permissions is to use the native installer provided by Claude. First ensure basic prerequisites are available:

sudo apt install -y curl git

Then run the installer script (you can review the script before running it if you prefer):

curl -fsSL https://claude.ai/install.sh | bash

Typical successful installer output:

Setting up Claude Code...

⚠ Setup notes:
 • ~/.local/bin is not in your PATH
 • Add it by running: export PATH="$HOME/.local/bin:$PATH"

✔ Claude Code successfully installed!

Version: 1.0.98

Location: ~/.local/bin/claude

Next: Run claude --help to get started

✅ Installation complete!

If the installer warns that ~/.local/bin is not in your PATH, add it and reload your shell (or log out and log back in):

export PATH="$HOME/.local/bin:$PATH"
# To persist, add the above line to ~/.profile or ~/.bashrc

After that, verify the installation:

claude --help

Example (truncated) output from claude --help:

--disallowedTools, --disallowed-tools <tools...>    Comma or space-separated list of tool names to deny (e.g. "Bash(git:*), Edit")
--mcp-config <configs...>                           Load MCP servers from JSON files or strings (space-separated)
--append-system-prompt <prompt>                    Append a system prompt to the default system prompt
--permission-mode <mode>                           Permission mode to use for the session (choices: "acceptEdits", "bypassPermissions", "default", "plan")
...
Commands:
  config                   Manage configuration (eg. claude config set -g theme dark)
  mcp                      Configure and manage MCP servers
  migrate-installer        Migrate from global npm installation to local installation
  setup-token              Set up a long-lived authentication token (requires Claude subscription)
  doctor                   Check the health of your Claude Code auto-updater
  update                   Check for updates and install if available
  install [options] [target] Install Claude Code native build...

Security tip: Always inspect a script before piping it into bash, especially in production or sensitive environments. Review https://claude.ai/install.sh if you have concerns.

Notes, troubleshooting, and closing

Root cause on many cloud images: the default global npm folder is owned by root, causing EACCES when non-root users attempt a global install. Using a user-local npm prefix or the native installer avoids this.
If you previously attempted sudo npm install -g @anthropic-ai/claude-code, you can use the migrate-installer command after installing the native binary to cleanly transition:
claude migrate-installer
If the claude executable still isn’t found after installing and adjusting PATH, confirm ~/.local/bin/claude exists and that echo $PATH contains ~/.local/bin.
Package behavior on specific cloud images may change over time; the native installer is a robust alternative when global npm installs present permission problems.

Example diff snippet referenced in the original instructions:

function greet() {
- console.log("Hello, World!");
+ console.log("Hello, Claude!");
}

Introduction

Getting Started with Claude Code

Working with Claude Code

Code Review with Claude Code

Security Auditing with Claude Code

Advanced Features

Installing Claude on Ubuntu Virtual Machines

Watch Video

Practice Lab