# CLAUDE CODE

*Setup Reference Card*

Anthropic's agentic command-line coding tool • Docs: [docs.claude.com/claude-code](https://docs.claude.com/en/docs/claude-code/overview)

Claude Code is a terminal-based agent that reads and edits files, runs commands, and works directly inside your repository. It also ships IDE plugins for VS Code and JetBrains, and a desktop app if you prefer to skip the terminal.

## 1 · Install

The **native installer** is the recommended method on every platform. It does not require a Node.js installation, and it auto-updates in the background. Pick *one* method per machine — do not mix installers.

| **Platform** | **Command** | **Updates** |
|----|----|----|
| **macOS / Linux / WSL** | curl -fsSL https://claude.ai/install.sh \| bash | Automatic |
| **Windows** (PowerShell) | irm https://claude.ai/install.ps1 \| iex | Automatic |
| **macOS** (Homebrew) | brew install --cask claude-code | brew upgrade |
| **Windows** (WinGet) | winget install Anthropic.ClaudeCode | winget upgrade |

**Legacy npm method** (deprecated, requires Node.js 18+; the native installer is preferred):

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

**Verify the install** — open a new terminal in your project, then:

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<th><p>claude --version # confirm the binary is on your PATH</p>
<p>claude doctor # diagnose install type, auth, PATH, MCP</p>
<p>claude # start an interactive session</p></th>
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| **PATH tip:** the native installer places the binary at ~/.local/bin/claude. If claude isn't found, reopen your terminal or add that directory to your PATH. |
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## 2 · Connect a Model Provider —Model Access Gateway (MAG)

### Step 1 – Get an American Science Cloud (AmSC) Account

Follow the instructions listed here: <https://amsc-docs-d762d2.gitlab.io/GM-getting-started#access--login> to create an AmSC account. Once the account is approved, proceed to the next step.

### Step 2 — Request MAG access and generate a Personal Access Token (PAT)

Follow the instructions listed here: <https://amsc-docs-d762d2.gitlab.io/model-access-gateway#quick-start>

### Step 3 — Set environment variables

Add these to your shell profile (~/.bash_profile, ~/.zshrc, or PowerShell \$PROFILE). Match the model names to what your key provides.

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<th><p># Core connection</p>
<p>export ANTHROPIC_AUTH_TOKEN=&lt;your-MAG-PAT&gt;</p>
<p>export ANTHROPIC_BASE_URL=https://i2-api.genesis.american-science-cloud.org/</p>
<p>export ANTHROPIC_MODEL=claude-opus-4-8</p>
<p># Per-tier models (for: claude --model &lt;opus|sonnet|haiku&gt;, plan mode)</p>
<p>export ANTHROPIC_DEFAULT_OPUS_MODEL=claude-opus-4-8</p>
<p>export ANTHROPIC_DEFAULT_SONNET_MODEL=claude-sonnet-4-6</p>
<p>export ANTHROPIC_DEFAULT_HAIKU_MODEL=claude-haiku-4-5</p>
<p># Optional</p>
<p>export DISABLE_TELEMETRY=1</p>
<p>#export ANTHROPIC_LOG=debug # uncomment for verbose logging</p></th>
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**Step 3 — Run Claude** claude in your project directory. Confirm the active model and provider (“API Usage Billing”) in the welcome banner and via the /status slash command.

| **Other providers:** Claude Code also supports Amazon Bedrock. See the AmSC documentation and [Claude Code docs](https://code.claude.com/docs/en/amazon-bedrock) for Bedrock setup (enable models, configure AWS CLI, set provider env vars). |
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## 3 · Per-Project Settings

Drop a .claude/settings.local.json for machine-local overrides, and do not commit the file containing the secret token to a version-control system:

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<th><p>{</p>
<p>"env": {</p>
<p>"ANTHROPIC_BASE_URL": "https://i2-api.genesis.american-science-cloud.org/",</p>
<p>"ANTHROPIC_AUTH_TOKEN": "&lt;your-MAG-PAT&gt;",</p>
<p>"ANTHROPIC_MODEL": "claude-opus-4-8"</p>
<p>}</p>
<p>}</p></th>
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## 4 · CLAUDE.md — Project Context

A CLAUDE.md file gives Claude Code standing context. It reads the file in the current directory *plus* every CLAUDE.md up the parent tree, and a global ~/.claude/CLAUDE.md. Use it for stack notes, code-style rules, and common commands.

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<th><p># ./CLAUDE.md (project root)</p>
<p>## Technologies</p>
<p>- Web framework: FastAPI + Ariadne (GraphQL)</p>
<p>- Database: PostgreSQL + SQLAlchemy 2.0 with Alembic migrations</p>
<p>## Code Style</p>
<p>- Never use local imports.</p>
<p>- Type annotations required on all functions; 4-space indent, PEP 8.</p>
<p>## Testing</p>
<p>- Use model_utils.py for test data; aim for 80%+ coverage.</p>
<p>- Avoid excessive mocking; every test has a docstring.</p></th>
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| **Keep secrets out of CLAUDE.md.** CLAUDE.md is context that often gets committed to version control. Put API keys and tokens in environment variables or .claude/settings.local.json (git-ignored) instead — never paste a live key into CLAUDE.md. |
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## 5 · Everyday Commands

| **Command** | **What it does** |
|----|----|
| claude | Start an interactive session in the current directory |
| claude "..." | Run a one-off prompt, e.g. claude "explain the auth flow" |
| claude --model \<tier\> | Pick a tier: opus / sonnet / haiku |
| claude mcp list | List configured MCP servers |
| claude update | Apply a pending update immediately |
| claude doctor | Diagnostics: install type, version, PATH, auth, MCP |

Useful slash commands in the TUI:

| /init | Generate a starter CLAUDE.md for the project (in-session) |
|-------|-----------------------------------------------------------|
| /help | List slash commands; /status shows auth & limits          |