Agentic Engineering: Mastering Your Terminal with Claude Code

Prerequisites and Environment Setup

To use this workflow, you need a foundational understanding of terminal operations and

version control. While

Claude Code

manages much of the heavy lifting, knowledge of

Next.js

or

React

project structures is helpful for verifying the agent's output. Ensure you have

Node.js

installed and a valid

GitHub

account for remote synchronization.

Key Libraries & Tools

• Claude Code: The primary agentic CLI tool that executes commands and edits files.
• Next.js: The framework used in this demonstration for building the customer support application.
• Vitest/Jest: Essential for the testing cycles the agent performs to ensure code integrity.
• GitHub: The destination for pushing finalized, agent-committed changes.

Code Walkthrough: Feature Implementation

When you initialize

in a repository, it performs a recursive scan of the file tree. You don't need to specify paths. For example, to add a chat history sidebar, you simply provide the natural language command:

# Example command within the Claude Code CLI
claude "Replace the left sidebar with a chat history and add a new chat button"

The agent analyzes layout.tsx and relevant component files, identifies the state management logic, and generates the necessary

updates. It presents a diff for your approval before writing to disk. Once approved, you can chain commands to automate the "boring" parts of the lifecycle:

# Running tests and fixing failures automatically
claude "Run tests and fix any errors you find"

Syntax Notes & Best Practices

relies on permission-based execution. It will explicitly ask to run shell commands or write files. Always review the "Thinking" block provided by the agent. This transparency helps you catch logic errors before they are committed. When the agent fixes build errors, it uses an iterative loop: build, catch error, patch, and re-build until the exit code is zero.

Practical Examples

• Legacy Code Onboarding: Point the tool at an old repository and ask it to generate a README or explain the data flow.
• Test-Driven Refactoring: Ask the agent to write a suite of unit tests for an existing function and then refactor the function for better performance while keeping the tests green.

Tips & Gotchas

Avoid giving overly broad instructions in large repositories to prevent unnecessary token usage. Break complex features into smaller, verifiable chunks. If the agent gets stuck in a loop during build fixes, manually intervene by providing a specific hint about the dependency or configuration file causing the conflict.