Claude Code

What is Claude Code?

Claude Code is a terminal-based coding agent built by Anthropic, the AI company behind the Claude models. You launch it inside your project directory and describe what you want in plain language, then Claude takes over: it explores the codebase, edits files, runs tests, fixes errors and even commits and opens pull requests. The whole session happens in your terminal, which feels surprisingly natural once you try it.

Anthropic released Claude Code as a research preview in February 2025 alongside Claude 3.7 Sonnet, and it rapidly became a staple for developers who like the agentic workflow. Because it runs locally against your real repository, it can execute commands and observe their output, which is what separates it from chat-only assistants.

It works with a subscription-based model: if you have a Claude Pro, Max, Team or Enterprise plan, you get a monthly allowance of Claude Code usage, and heavier use can be billed through the Anthropic API. There are also integrations with GitHub, so the agent can work with issues and pull requests.

Key Features

• Full agent loop: reads, edits and runs commands in your repo
• Plain-language tasks from 'add a test' to 'migrate this module'
• GitHub integration for issues and pull requests
• Multiple subagents and parallel tasks for large changes
• CLI hooks, permissions and MCP tool support for customization
• Session resume, so long projects pick up where you left off
• Available as an IDE extension for VS Code and JetBrains too

How to get started

Install Claude Code with a single command from your terminal, then authenticate with your Claude account. From there you navigate into any project, start claude, and ask for the first task. The agent will ask permission before running commands if you keep the default safety settings, which is a good way to learn what it can do.

• Install Claude Code following the official docs
• Log in with your Claude account or API key
• Open your terminal in a project folder
• Start claude and describe a task in plain English
• Review the changes it makes and let it run tests

Use cases

• Implementing features across multiple files in one session
• Refactoring and renaming across a large codebase
• Writing and running tests until they pass
• Fixing bugs by letting the agent trace the code and errors
• Automating repetitive commits and pull request chores
• Pair programming from a terminal, including over SSH

Pricing and licensing

Claude Code is proprietary and is included with Anthropic's Claude subscriptions rather than sold as a standalone product. Subscribers get a monthly usage allowance, and heavy users can connect their own API billing for extra capacity. The exact limits and prices change as Anthropic tunes the product, so check the official site.

From a licensing standpoint you keep ownership of the code it writes, and the tool supports enterprise controls like audit logs and permissions. For individuals the main cost is the Claude subscription itself.

Pros and cons

The strength is autonomy with accountability. Claude Code does real work in your actual repository and shows you the diff, so you stay in control while the agent handles the grunt work. The terminal-based workflow also fits remote machines, containers and SSH sessions perfectly.

The downsides are trust and cost. Agents occasionally make surprising changes, so review discipline matters, and large workloads can burn through subscription allowances quickly. It is also proprietary, so some teams prefer open alternatives for compliance reasons.

Alternatives

• GitHub Copilot agent mode: AI assistance inside VS Code and other editors
• Cursor: AI-first editor with its own agent features
• OpenAI Codex: another terminal-based coding agent
• Aider: open-source terminal AI pair programmer
• Windsurf: agentic editor from Cognition AI