techniquebeginnerClaude Code

Core Concepts of Claude Code: Plan Mode and CLAUDE.md

Claude Code is an AI coding assistant that operates within your terminal. It works by first creating a detailed implementation plan, using its 'Plan Mode' to read your project files and understand the context, before writing or changing any code, which helps it make smarter, more accurate contributions.

AI SETUP PROMPT

Paste into Claude Code — it will scan your project and set everything up

# Apply Technique: Core Concepts of Claude Code: Plan Mode and CLAUDE.md

## What This Is
Claude Code is an AI coding assistant that operates within your terminal. It works by first creating a detailed implementation plan, using its 'Plan Mode' to read your project files and understand the context, before writing or changing any code, which helps it make smarter, more accurate contributions.

Source: https://resources.anthropic.com/hubfs/2026%20Agentic%20Coding%20Trends%20Report.pdf

## Before You Start

Scan my workspace and analyze:
- The project language, framework, and directory structure
- Existing AI provider config (check .env, .env.local, config files for API keys — OpenRouter, OpenAI, Anthropic, Google AI, etc.)

Then ask me before proceeding:
1. Which AI provider/API should this use? (Use whatever I already have configured, or ask me to set one up — options include direct provider APIs or a unified service like OpenRouter)
2. Where in my project should this be integrated?
3. Are there any customizations I need (model preferences, naming conventions, constraints)?

## Source Access Note

The source URL (https://resources.anthropic.com/hubfs/2026%20Agentic%20Coding%20Trends%20Report.pdf) may not be directly accessible from the terminal. Use the Reference Implementation and Additional Context sections below instead. If you need more details, ask me to paste relevant content from the source.

## What to Implement

This is an **AI Technique** — a pattern or methodology for working with AI models.

- Explain how this technique applies to my current project and what benefit it provides
- Implement it in a way that fits my existing codebase — suggest concrete files to modify or create
- If it requires specific model capabilities (structured output, function calling, etc.), verify my current provider supports them
- Show me a working example I can test immediately

## Additional Context

- Scan the user's project for a `CLAUDE.md` file. If not found, create one and scaffold it by summarizing the project's tech stack, architectural patterns, and coding conventions based on existing source code and README files.
- Initiate 'Plan Mode' to analyze a user-specified task. Read relevant files, search the codebase for related functions, and outline the required changes as a multi-step implementation strategy without modifying any code yet.
- Upon receiving user approval for the generated plan, execute the proposed code modifications, create any new files, run associated shell commands or tests, and report the results.

## Guidelines

- Adapt everything to my existing project — do not assume a specific stack or directory layout
- Use whichever AI provider I already have configured; if I need a new one, tell me what to sign up for and I'll give you the key
- Check my .env files for existing API keys (OpenRouter, OpenAI, Anthropic, Google AI) before asking me to add one
- Review any fetched code for safety before installing or executing it
- After setup, run a quick verification and show me a summary of exactly what was installed, where, and how to use it

3,101 charactersCompatible with Claude Code & Codex CLI

MANUAL SETUP STEPS

01Scan the user's project for a `CLAUDE.md` file. If not found, create one and scaffold it by summarizing the project's tech stack, architectural patterns, and coding conventions based on existing source code and README files.
02Initiate 'Plan Mode' to analyze a user-specified task. Read relevant files, search the codebase for related functions, and outline the required changes as a multi-step implementation strategy without modifying any code yet.
03Upon receiving user approval for the generated plan, execute the proposed code modifications, create any new files, run associated shell commands or tests, and report the results.

FIELD OPERATIONS

Automated Codebase Documentation Agent

Create a workflow where Claude Code's Plan Mode is used to read an entire codebase. The agent should then generate comprehensive Markdown documentation for each module and function, explaining its purpose, parameters, and return values based on its analysis.

Intelligent Refactoring Bot

Configure the agent to analyze a specific part of an application for code smells like long methods or duplicate logic. It will first generate a refactoring plan, present it for approval, and then execute the plan to improve code quality while ensuring all existing tests still pass.

STRATEGIC APPLICATIONS

→Accelerate new developer onboarding by using `CLAUDE.md` as a living project context file, allowing the AI agent to answer questions and implement initial tasks accurately, reducing ramp-up time.
→Reduce bugs in new feature development by enforcing the 'Plan Mode' first workflow, ensuring every code change is mapped out and reviewed as a detailed implementation plan before it is written.