Install Claude Code (2026)

TL;DR: Install with npm install -g @anthropic-ai/claude-code, authenticate with claude /login or set ANTHROPIC_API_KEY, and verify with claude --version.

The Problem

You want to install Claude Code but are unsure which method works for your platform, or your installation attempt failed with errors like:

npm ERR! code EACCES
npm ERR! permission denied

Or Claude Code installed but does not start.

Why This Happens

Claude Code is distributed as an npm package that requires Node.js 18+. Installation issues typically stem from missing Node.js, incorrect npm permissions, or platform-specific PATH configuration.

The Fix

Step 1 — Install Node.js (if needed)

Claude Code requires Node.js 18 or later.

macOS:

# Using Homebrew
brew install node
# Verify version (must be 18+)
node --version

Ubuntu / Debian:

# Using NodeSource
curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt-get install -y nodejs
node --version

Windows:

# Using winget
winget install OpenJS.NodeJS
# Or download from https://nodejs.org

WSL:

# Same as Ubuntu/Debian
curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt-get install -y nodejs

Step 2 — Install Claude Code

# Install globally
npm install -g @anthropic-ai/claude-code
# If you get EACCES permission errors:
# Option A: Fix npm permissions
mkdir -p ~/.npm-global
npm config set prefix '~/.npm-global'
echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.zshrc
source ~/.zshrc
npm install -g @anthropic-ai/claude-code
# Option B: Use npx (no global install)
npx @anthropic-ai/claude-code

Step 3 — Authenticate

# Interactive login (opens browser)
claude /login
# Or set API key directly (works in all environments)
export ANTHROPIC_API_KEY="sk-ant-api03-your-key-here"

Step 4 — Verify Installation

# Check version
claude --version
# Check auth status
claude auth status
# Run a quick test
echo "What is 2+2?" | claude --print

Expected output:

Claude Code v2.1.107
Authenticated as: you@example.com
4

Docker Installation

FROM node:20-slim
RUN npm install -g @anthropic-ai/claude-code
# Set API key at runtime, not in Dockerfile
ENV ANTHROPIC_API_KEY=""
ENTRYPOINT ["claude"]

# Build and run
docker build -t claude-code .
docker run -it -e ANTHROPIC_API_KEY="$ANTHROPIC_API_KEY" claude-code

VS Code Extension

  1. Open VS Code
  2. Go to Extensions (Cmd+Shift+X / Ctrl+Shift+X)
  3. Search “Claude Code”
  4. Install the official Anthropic extension
  5. The extension uses the CLI under the hood — ensure claude is on your PATH

Common Variations

Scenario Cause Quick Fix
npm ERR! EACCES Global npm needs root Use ~/.npm-global prefix or npx
command not found: claude Not on PATH Add npm global bin to PATH
Node version too old <18 installed Update Node.js via nvm or package manager
Works in terminal, not in VS Code VS Code uses different PATH Add npm bin to VS Code terminal profile
WSL: claude starts but no output Shell snapshot issue (v2.1.105) Update to latest version

Prevention

  • Use nvm for Node.js management: nvm install 20 && nvm use 20 lets you switch versions without sudo.
  • Pin Claude Code version in CI: Use npm install -g @anthropic-ai/claude-code@2.1.107 for reproducible builds.
**Written by Michael** — solo dev, Da Nang, Vietnam. 50K+ Chrome extension users. $500K+ on Upwork (100% Job Success). Runs 5 Claude Max subs in parallel. Built this site with autonomous agent fleets. [See what I'm building →](https://zovo.one)
**Without a CLAUDE.md — what actually happens:** You type: "Add auth to my Next.js app" Claude generates: `pages/api/auth/[...nextauth].js` — wrong directory (you're on App Router), wrong file extension (you use TypeScript), wrong NextAuth version (v4 patterns, you need v5), session handling that doesn't match your middleware setup. You spend 40 minutes reverting and rewriting. Claude was "helpful." **With the Zovo Lifetime CLAUDE.md:** Same prompt. Claude reads 300 lines of context about YOUR project. Generates: `app/api/auth/[...nextauth]/route.ts` with v5 patterns, your session types, your middleware config, your test patterns. Works on first run. You commit and move on. That's the difference a $99 file makes. **[Get the CLAUDE.md for your stack →](https://zovo.one/lifetime?utm_source=ccg&utm_medium=cta-beforeafter&utm_campaign=claude-code-install-guide)**
This took me 3 hours to figure out. I put it in a CLAUDE.md so I'd never figure it out again. Now Claude gets it right on the first try, every project. 16 framework templates. Next.js, FastAPI, Laravel, Rails, Go, Rust, Terraform, and 9 more. Each one 300+ lines of "here's exactly how this stack works." Copy into your project. Done. **[See the templates →](https://zovo.one/lifetime?utm_source=ccg&utm_medium=cta-config&utm_campaign=claude-code-install-guide)** $99 once. Yours forever. I keep adding templates monthly.

Get started → Generate your project setup with our Project Starter.

Configure permissions → Build your settings with our Permission Configurator.

Try it: Paste your error into our Error Diagnostic for an instant fix.

Last verified: 2026-04-14. Found an issue? Open a GitHub issue.