Claude Code: Everything You Need to Know
From first prompt to agent teams — one guide.
A practical guide to Claude Code — from your first prompt to multi-agent automation, hooks, MCP, and team workflows. Built around clear mental models and real examples, not marketing.
npm install -g @anthropic-ai/claude-code
Who this is for: Developers using (or about to use) Claude Code. Beginners get a guided path; power users get depth on Skills, Hooks, MCP, and Agent Teams.
🧭 Choose your path
| You are… | Start here | Time |
|---|---|---|
| 🚀 New to Claude Code | Setup → Prompt Engineering → Your First Skill | ~15 min |
| ⚡ Already using it, want depth | Skills · Hooks · MCP | ~30 min each |
| 🧠 Building teams or automation | Dynamic Workflows · Agent Teams · BMAD | varies |
🧠 When to use what
The five extension points in Claude Code, side by side:
| Tool | Use when… | Skip if… | Lives in |
|---|---|---|---|
| Skills (slash commands) | You repeat the same prompt or workflow ≥3 times | One-off task | .claude/commands/*.md |
| Hooks | You want code to run automatically on tool use, session start, etc. | You only want manual triggers | .claude/settings.json |
| Subagents | A subtask is big enough to need its own isolated context | The task fits in your main session | .claude/agents/*.md |
| Workflows | The job needs more agents than one conversation can coordinate | A couple of subagents would do | .claude/workflows/*.js |
| MCP servers | You need Claude to use external tools (browsers, DBs, APIs) | All your data is in local files | Configured per project |
💡 These five compose. Most polished setups combine 2–3.
📚 What's inside
Fundamentals — What is Claude Code? · Setup · Prompt Engineering
Workflow extensions — Slash Commands · Skills · Hooks
Multi-agent & integration — Subagents · Dynamic Workflows · Agent Teams · Automation surface · MCP
Productivity & frameworks — Effort levels · Fast Mode · Super Claude · BMAD Method
Reference — Slash Command Cheatsheet · Effort levels · Workflows · Agent Teams · Skills · FAQ · Updates & Deprecations · Further Reading
What is Claude Code?
Claude Code is Anthropic's official CLI for working with Claude from your terminal. You point it at a project; it reads the code, plans, edits files, runs commands, and commits — all from the prompt line.
Three things it does that a chat UI can't:
- Reads your actual repo — not pasted snippets. Claude sees your file tree, runs
grep, follows imports, and grounds answers in real context. - Edits in place and runs your tests — diff-aware edits, then
pytest/vitest/go teston the spot to verify the change. - Composes with the rest of your stack — slash commands, hooks, sub-agents, MCP servers, and your normal git/shell workflow.
If you've used Copilot or Cursor, think of Claude Code as their "agent in your terminal" peer — same idea, different surface, no editor lock-in.
claude # start a session in the current repo
> explain what this codebase does
> fix the failing test in src/api.test.ts
> open a PR with the changes
The Claude 5 era: today's model lineup
Three launches landed in quick succession this summer: Claude Opus 4.8 (May 28, 2026) took over as the Opus-tier flagship, Claude Fable 5 and its restricted sibling Claude Mythos 5 (June 9, 2026) opened a new Mythos-class tier above Opus, and Claude Sonnet 5 (June 30, 2026) became Claude Code's default model. 1M-token context is now standard across current Opus, Sonnet, and Fable models — no beta flag, no long-context surcharge — with 128K max output.
Choosing a model — quick guide:
| Model | Reach for it when… |
|---|---|
| Sonnet 5 (default) | Everyday coding — most tasks live here. Intro pricing $2/$10 per MTok through Aug 31, 2026 (then $3/$15) |
| Opus 4.8 | Complex reasoning, large refactors, orchestrating agents — $5/$25, unchanged from 4.7 |
| Fable 5 | Genuinely hard problems — Mythos-class capability above Opus at $10/$50 |
| Haiku 4.5 | Fast, lightweight tasks — quick questions, doc updates ($1/$5, 200K context) |
Opus 4.7 / 4.6 and Sonnet 4.6 are now legacy models (still available via API and
/model); Opus 4.1 retires August 5, 2026. Mythos 5 is the same underlying model as Fable 5 with fewer safeguards — invitation-only for approved organizations via Project Glasswing.→ Full specs, capabilities, and pricing in
docs/reference/models.md
Claude Code Setup
⏱️ 5-minute setup. Get from zero to your first AI-assisted commit.
1. Install
npm install -g @anthropic-ai/claude-code
Requires Node.js 18+. For other install methods (Homebrew, curl, native binary), see the official install guide.
2. Authenticate
claude
On first run, Claude Code opens a browser to sign in with your Anthropic account (Pro, Max, or API key all work). After that, you can re-authenticate any time with /login (and sign out with /logout) inside a session, or claude auth login|status|logout from your shell.
3. Run your first prompt
From any project directory:
cd ~/your-project
claude
Once Claude Code is running, try one of these:
explain what this codebase does— Claude reads your repo and summarizes.add a README section about installation— generates content based on your project.find and fix the failing test in src/api.test.ts— diagnoses and edits in place.
4. (Optional) Generate a CLAUDE.md
/init
Creates a project-level instruction file that Claude reads on every session — your project's "house rules." More on this in Prompt Engineering Deep Dive.
5. (Bonus) Steal this repo's setup
This repo's .claude/ directory is a working, runnable Claude Code project — one of each extension point, not screenshots of one. Every path below is something you can copy into your own project today:
| Path | What you get | Copy it when… |
|---|---|---|
.claude/commands/ |
7 slash skills — /pr, /review, /tdd, /test, /five, /ux, /todo |
You want PR hygiene and review rigor without writing the prompts |
.claude/skills/ |
An Agent Skill — /claude-md-review audits a CLAUDE.md for vagueness, dead paths, and bloat |
You want a worked example of the frontmatter contract |
.claude/agents/ |
5 subagents, plus 10 more role prompts in specialized-agents/ |
You want specialists without authoring role prompts — they double as Agent Teams teammates |
.claude/workflows/ |
A dynamic workflow — /stale-docs-audit fans agents across your docs, then refutes its own findings |
You want a real script to read before writing your own |
.claude/hooks/ |
Python hooks — post_tool_use.py, notification.py, stop.py, subagent_stop.py |
You want lifecycle automation (needs uv) |
.claude/settings.json |
Permissions + hook wiring | You're copying the hooks — swap the hardcoded uv path for $(which uv) |
git clone --depth 1 https://github.com/wesammustafa/Claude-Code-Everything-You-Need-to-Know /tmp/cc-guide
cp -r /tmp/cc-guide/.claude/commands/pr.md your-project/.claude/commands/ # take what you want
⚠️ Read before you copy. Skills, hooks, agents, and workflows are executable instructions that run with your permissions — including from this repo. Copy file by file and read each one, the same way you'd review a shel