What is Claude Code? 2026 Comprehensive Turkish Guide: Setup, Hooks, MCP, Sub-Agents

## 1. What is Claude Code? Anthropic's terminal/CLI agentic AI coding assistant launched Feb 2025. Direct access to Claude models with MCP, sub-agents, hooks, and IDE-agnostic architecture. ## 2. Installation npm install -g @anthropic-ai/claude-code then claude login. Requires Node 18+, supports macOS/Linux/Windows. ## 3. CLAUDE.md A project-root markdown file that Claude Code reads every session. Contains tech stack, git policy, security rules, file layout, conventions. Hierarchy: global (~/.claude/CLAUDE.md), project (./CLAUDE.md), local (./CLAUDE.local.md). ## 4. Slash Commands Built-in: /init, /clear, /compact, /mcp, /hooks, /cost, /model, /permissions, /agents. Custom slash commands defined in ~/.claude/commands/*.md. ## 5. MCP — Model Context Protocol Anthropic's open protocol for connecting LLMs to external tools. Popular servers: github, postgres, linear, notion, sentry, slack. Configure in ~/.claude/mcp.json. ## 6. Hooks PreToolUse, PostToolUse, UserPromptSubmit, Stop, Notification, SubagentStop. Define in settings.json. Harness-enforced (not Claude-enforced) — safe to rely on for security. ## 7. Sub-Agents Task tool delegates work to sub-agents. Built-in: general-purpose, code-reviewer, Plan, Explore. Custom in ~/.claude/agents/*.md. ## 8. Use Cases - Repo onboarding - Migration (Express → Next.js) - Test coverage improvement - Production bug fix (with Sentry MCP) - KVKK audit (custom sub-agent) - Schema migration (with Postgres MCP) - Multi-service refactor - i18n completion ## 9. KVKK Compliance For sensitive code/IP, use Claude Team or Enterprise. Anthropic EU region (Frankfurt) for data residency. Hooks can enforce TC kimlik no / IBAN / credit card regex blocking. ## 10. Conclusion Claude Code is the gold standard for agentic coding. CLAUDE.md + hooks + sub-agents combination automates 40-60% of senior engineer tasks. Strong Turkish fluency + KVKK alignment make it a top choice for Turkish developers.