How to use Claude Code: a practical guide

To use Claude Code, install it, run claude in your project, give it a CLAUDE.md, and describe each task as specifically as you would to a colleague. Use plan mode for anything bigger than a small fix, interrupt it the moment it heads the wrong way, and connect your other tools with MCP so it can look things up instead of guessing.

Claude Code is Anthropic’s coding agent. It reads your files, runs commands and edits code from a session in your terminal, and asks before it does anything you haven’t allowed. The steps below follow Anthropic’s own documentation, in the order you will need them.

1. Install Claude Code and sign in

The native installer is the recommended route on macOS, Linux and WSL:

curl -fsSL https://claude.ai/install.sh | bash

On Windows PowerShell, run irm https://claude.ai/install.ps1 | iex. Homebrew (brew install --cask claude-code) and WinGet (winget install Anthropic.ClaudeCode) work too, but only the native install updates itself in the background.

Open a new terminal and check it worked:

claude --version

Then start it inside a project:

cd ~/code/my-app
claude

The first run asks you to sign in. A Claude Pro, Max, Team or Enterprise subscription works, as does a Claude Console account with API credits, or Amazon Bedrock, Google Cloud or Microsoft Foundry for teams that buy models through their cloud.

2. Ask before you change anything

Claude Code reads files as it needs them, so you don’t have to paste code into the prompt. Start with questions that make it read the project:

what does this project do, and where is the main entry point?

how does a request get from the router to the database here?

Then give it a task, and be specific. “Fix the bug” leaves it guessing. “Fix the login bug where users see a blank screen after a wrong password” tells it where to look and what done means. For larger work, list the steps in order, and say how to check the result: which test to run, which page to load.

3. Write a CLAUDE.md

Every session starts with an empty context. A CLAUDE.md file is how you give every session the same starting knowledge. Run this inside a session:

/init

/init reads the codebase and writes a CLAUDE.md with the build commands, test instructions and conventions it finds. Edit it down to what matters: the commands to build, test and lint, the rules a new engineer would get wrong, and the directories to stay out of.

Claude Code loads these files at launch:

A CLAUDE.md can pull in other files with @path/to/file, so a long architecture document can live in docs/ and still load. Keep the file short and concrete: the docs note that the more specific and concise your instructions are, the more consistently they are followed. CLAUDE.md guides what Claude does; to block an action outright, use a hook.

4. Choose a permission mode

Claude Code asks before it edits files or runs commands. Press Shift+Tab to cycle the permission mode of the current session:

• Manual (default): it asks before edits and commands.
• Accept edits (acceptEdits): it edits files without asking, and still asks before other actions.
• Plan (plan): it reads and plans, and changes nothing until you approve the plan.

Plan mode is the one to reach for on anything that touches more than a few files. Read the plan, correct it, then let it work. You can start a session in it directly:

claude --permission-mode plan

5. Steer it while it works

You will get better results from steering early than from fixing late. The controls worth learning first:

• Esc stops the current response or tool call. Claude keeps the work done so far, and you can redirect it.
• Esc Esc on an empty prompt opens the rewind menu, which restores the session to an earlier point.
• @ autocompletes a file path, so you can point it at the exact file.
• ! at the start of the prompt runs a shell command and adds its output to the session.
• /clear wipes the conversation. Use it between unrelated tasks so old context stops steering new work.

To pick up where you left off, claude -c continues the most recent conversation in the directory and claude -r opens a picker of earlier sessions.

6. Run it from scripts

claude -p runs a single prompt and exits, which makes Claude Code usable in scripts and CI:

claude -p "explain what changed in the last commit"
cat build.log | claude -p "why did this build fail?"
claude -p "list the TODOs in src/" --output-format json

In print mode, --max-turns caps how many steps it takes and --allowedTools lists the tools it may use without asking, so an unattended run cannot wander.

7. Connect your other tools with MCP

Claude Code can call tools outside your repository through the Model Context Protocol. Add a remote server with one command:

claude mcp add --transport http <name> <url>

Servers are added for you in the current project by default. Add --scope project to write the server to a .mcp.json at the repository root, which you commit so the whole team gets it, or --scope user to have it in every project. Run /mcp inside a session to check each server’s status and to sign in to servers that use OAuth.

Production is the context Claude Code usually lacks. It can read the code that broke, but not the logs, traces and deploys that show how it broke. Polylane gives Claude Code that context through one MCP server that covers every provider you connect:

claude mcp add --transport http polylane https://mcp.polylane.com/mcp

Then ask it what you would otherwise open five dashboards for, such as why checkout started returning 502s this morning, and it answers from the real data.

Using Claude Code? See how to give Claude Code production context with Polylane.