Claude Code 101 — CLI Mental Model

Key Takeaways

• Claude Code is a CLI-native agentic runtime, not a chatbot wrapper — it executes an autonomous loop of read, reason, tool-call, and verify steps directly against your local or remote codebase.
• The permission model is an explicit ACL matrix: each tool capability (file read, file write, shell exec, web fetch) must be individually authorized — scope it to the minimum surface area required, exactly as you would a service-account in a zero-trust mesh.
• Context window is Claude Code's working memory — treat it like a bounded transaction buffer; large codebases require deliberate chunking strategies to avoid context overflow corrupting multi-step refactoring accuracy.
• Memory anchor: api-gateway-sidecar-proxy — Claude Code sits as a sidecar to your dev workflow, intercepting and orchestrating tool calls with its own permission-enforcement layer, just as a sidecar proxy mediates service-to-service traffic in a mesh.