Claude Code Installation Guide

Claude Code is Anthropic's terminal agent. It reads your repository, edits files, runs commands and works through a plan with you — from the shell, in CI, or inside your editor.

System Requirements

• macOS 13.0+, Windows 10 1809+ / Server 2019+, Ubuntu 20.04+, Debian 10+, Alpine 3.19+
• 4 GB RAM, x86_64 or ARM64
• An internet connection
• A Pro, Max, Team, Enterprise or Console account — the free claude.ai plan does not include Claude Code. You can also use it with Amazon Bedrock, Google Cloud or Microsoft Foundry.

Installation Instructions

The Native Installer (Recommended)

# macOS, Linux and WSL
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

REM Windows CMD
curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd

The installer shows no progress while it downloads. When it finishes, open a new terminal and check the version:

claude --version

Native installations update themselves in the background.

Linux Package Managers

Claude Code publishes signed apt, dnf and apk repositories. Each has a stable channel (about a week old, skips regressions) and a latest channel (every release as it ships).

# Prerequisites
sudo apt install curl gnupg
 
# The signing key
sudo install -d -m 0755 /etc/apt/keyrings
sudo curl -fsSL https://downloads.claude.ai/keys/claude-code.asc \
  -o /etc/apt/keyrings/claude-code.asc
 
# Check the fingerprint — it must be 31DDDE24DDFAB679F42D7BD2BAA929FF1A7ECACE
gpg --show-keys /etc/apt/keyrings/claude-code.asc
 
# The repository
echo "deb [signed-by=/etc/apt/keyrings/claude-code.asc] https://downloads.claude.ai/claude-code/apt/stable stable main" \
  | sudo tee /etc/apt/sources.list.d/claude-code.list
 
sudo apt update
sudo apt install claude-code

Other Options

# Homebrew (stable channel)
brew install --cask claude-code
 
# Homebrew (latest channel)
brew install --cask claude-code@latest

# WinGet
winget install Anthropic.ClaudeCode

# npm — requires Node.js 22 or newer
npm install -g @anthropic-ai/claude-code

Alpine and musl distributions

Alpine needs bash, curl, libgcc, libstdc++ and ripgrep, plus USE_BUILTIN_RIPGREP=0:

apk add bash curl libgcc libstdc++ ripgrep

{
  "env": {
    "USE_BUILTIN_RIPGREP": "0"
  }
}

Signing In

# Start an interactive session and follow the browser prompts
claude
 
# Or authenticate with an API key
export ANTHROPIC_API_KEY="sk-ant-..."
claude

# Use a different provider — Bedrock, Google Cloud or Microsoft Foundry
export CLAUDE_CODE_USE_BEDROCK=1
export CLAUDE_CODE_USE_VERTEX=1
export CLAUDE_CODE_USE_FOUNDRY=1

Updates

# Update now
claude update
 
# Or let the background updater do it

{
  "autoUpdatesChannel": "stable",
  "minimumVersion": "2.1.100"
}

• "latest" (default) — new features as soon as they ship
• "stable" — about a week old, skips releases with major regressions

{
  "env": {
    "DISABLE_AUTOUPDATER": "1"
  }
}

DISABLE_AUTOUPDATER only stops the background check — claude update still works. Use DISABLE_UPDATES to block every update path.

Verifying the Release

Each release publishes a manifest.json with the SHA256 checksum of every platform binary, signed with the Anthropic GPG key:

# 1. Import the key and check the fingerprint
curl -fsSL https://downloads.claude.ai/keys/claude-code.asc | gpg --import
gpg --fingerprint security@anthropic.com
# 31DD DE24 DDFA B679 F42D  7BD2 BAA9 29FF 1A7E CACE
 
# 2. Download the manifest and its signature
REPO=https://downloads.claude.ai/claude-code-releases
VERSION=2.1.89
curl -fsSLO "$REPO/$VERSION/manifest.json"
curl -fsSLO "$REPO/$VERSION/manifest.json.sig"
 
# 3. Verify
gpg --verify manifest.json.sig manifest.json
# gpg: Good signature from "Anthropic Claude Code Release Signing <security@anthropic.com>"
 
# 4. Check the binary against the manifest
sha256sum ~/.local/share/claude/versions/2.1.89/claude

Troubleshooting

Best Practices

1. Use the native installer — it auto-updates and is the best tested path.
2. Verify the release manifest before you trust a downloaded binary.
3. Keep a project CLAUDE.md in the repository with the conventions the agent should follow, and commit it.
4. Use the stable channel on shared machines so nobody gets a broken release on a Monday morning.
5. Give the agent scoped permissions rather than the whole machine.
6. Use ANTHROPIC_API_KEY from a secret store, never from a committed file.
7. Run it in CI with a scoped token and a read-only checkout.

Next Steps

• Claude Code Documentation
• Claude Code on GitHub
• Gemini CLI
• OpenCode
• Git Installation Guide