Adding Claude-Craft to an Existing Project

This comprehensive tutorial guides you through adding Claude-Craft to a project that already has code. You'll learn how to safely install, make Claude understand your codebase, and push your first AI-assisted modifications.

Time required: ~20-30 minutes

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Table of Contents

1. Before You Start
2. Backup Your Project
3. Analyze Your Project Structure
4. Check for Conflicts
5. Choose Your Technology Stack
6. Install Claude-Craft
7. Merge Configurations
8. Make Claude Understand Your Codebase
9. Your First Modification
10. Team Onboarding
11. Migration from Other AI Tools
12. Troubleshooting

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1. Before You Start

Important Warnings

Warning: Installing Claude-Craft will create a .claude/ directory in your project. If one already exists, you'll need to decide whether to merge, replace, or preserve it.

Warning: Always create a backup branch before installation. This allows easy rollback if something goes wrong.

Prerequisites Checklist

• [ ] Your project is tracked in Git
• [ ] You have committed all current changes
• [ ] You have write access to the project directory
• [ ] Node.js 16+ installed (for NPX method)
• [ ] Claude Code installed

When NOT to Install

Consider postponing installation if:

• You have uncommitted changes
• You're in the middle of a critical release
• The project has complex existing .claude/ configuration
• Multiple team members are actively pushing changes

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2. Backup Your Project

Never skip this step. Create a backup branch before installation.

Create Backup Branch

# Navigate to your project
cd ~/your-existing-project

# Make sure everything is committed
git status

If you see uncommitted changes:

git add .
git commit -m "chore: save work before Claude-Craft installation"

Now create the backup:

# Create and stay on backup branch
git checkout -b backup/before-claude-craft

# Return to your main branch
git checkout main  # or 'master' or your default branch

Verify Backup

# Confirm backup branch exists
git branch | grep backup

Expected output:

  backup/before-claude-craft

Rollback Plan

If anything goes wrong, you can rollback:

# Discard all changes and return to backup
git checkout backup/before-claude-craft
git branch -D main
git checkout -b main

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3. Analyze Your Project Structure

Before installing, understand what you already have.

Check for Existing .claude Directory

# Check if .claude already exists
ls -la .claude/ 2>/dev/null || echo "No .claude directory found"

If .claude exists:

• Note what files are inside
• Decide: merge, replace, or preserve
• See Section 7: Merge Configurations

Identify Your Project Structure

# List root directory
ls -la

# Show directory tree (first 2 levels)
find . -maxdepth 2 -type d | head -20

Take note of:

• Main source directories (src/, app/, lib/)
• Configuration files (.env, config/, settings/)
• Test directories (tests/, test/, spec/)
• Documentation (docs/, README.md)

Check for Other AI Tool Configurations

# Check for Cursor rules
ls -la .cursorrules 2>/dev/null

# Check for GitHub Copilot instructions
ls -la .github/copilot-instructions.md 2>/dev/null

# Check for other Claude configs
ls -la CLAUDE.md 2>/dev/null

Note any existing configurations - you may want to migrate them (see Section 11).

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4. Check for Conflicts

Files That May Conflict

File/Directory	Claude-Craft Creates	Your Project May Have
.claude/	Yes	Maybe
.claude/CLAUDE.md	Yes	Maybe
.claude/rules/	Yes	Maybe
CLAUDE.md (root)	No	Maybe

Decision Matrix

Scenario	Recommendation
No .claude/ exists	Install normally
Empty .claude/ exists	Install with --force
.claude/ has custom rules	Use --preserve-config
Root CLAUDE.md exists	Keep it, it won't conflict

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5. Choose Your Technology Stack

Identify the primary technology of your project:

Your Project Uses	Install Command
PHP/Symfony	--tech=symfony
Dart/Flutter	--tech=flutter
Python/FastAPI/Django	--tech=python
JavaScript/React	--tech=react
JavaScript/React Native	--tech=reactnative
Multiple/Other	--tech=common

For monorepos: Install to each subproject separately (see below).

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6. Install Claude-Craft

Standard Installation

Method A: NPX (Recommended)

cd ~/your-existing-project
npx @the-bearded-bear/claude-craft install . --tech=symfony --lang=en

Method B: Makefile

cd ~/claude-craft
make install-symfony TARGET=~/your-existing-project LANG=en

Preserving Existing Configuration

If you have existing .claude/ files you want to keep:

# NPX with preserve flag
npx @the-bearded-bear/claude-craft install . --tech=symfony --lang=en --preserve-config

# Makefile with preserve flag
make install-symfony TARGET=~/your-existing-project LANG=en OPTIONS="--preserve-config"

What --preserve-config keeps:

• CLAUDE.md (your project description)
• rules/00-project-context.md (your custom context)
• Any custom rules you've added

Monorepo Installation

For projects with multiple apps:

my-monorepo/
├── frontend/    (React)
├── backend/     (Symfony)
└── mobile/      (Flutter)

Install to each directory:

# Install React to frontend
npx @the-bearded-bear/claude-craft install ./frontend --tech=react --lang=en

# Install Symfony to backend
npx @the-bearded-bear/claude-craft install ./backend --tech=symfony --lang=en

# Install Flutter to mobile
npx @the-bearded-bear/claude-craft install ./mobile --tech=flutter --lang=en

Verify Installation

ls -la .claude/

Expected structure:

.claude/
├── CLAUDE.md
├── agents/
├── checklists/
├── commands/
├── rules/
└── templates/

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7. Merge Configurations

If you had existing configurations, merge them now.

Merging CLAUDE.md

If you had a custom CLAUDE.md:

1. Open both files:

   # Your old file (if backed up)
   cat .claude/CLAUDE.md.backup
   
   # New Claude-Craft file
   cat .claude/CLAUDE.md

2. Copy your custom sections into the new file

3. Keep the Claude-Craft structure, add your content

Merging Custom Rules

If you had custom rules in rules/:

1. Claude-Craft rules are numbered 01-xx.md through 12-xx.md
2. Add your custom rules as 90-custom-rule.md, 91-another-rule.md
3. Higher numbers = lower priority, but still included

Example Merge

# Rename your old custom rule
mv .claude/rules/my-custom-rules.md .claude/rules/90-project-custom-rules.md

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8. Make Claude Understand Your Codebase

This is the most important section. A successful Claude-Craft setup isn't just about installing files—it's about making Claude truly understand your project.

8.1 Initial Codebase Exploration

Launch Claude Code in your project:

cd ~/your-existing-project
claude

Start with a broad exploration:

Explore this codebase and give me a comprehensive summary of:
1. The overall project structure
2. Main directories and their purposes
3. Key entry points
4. Configuration files you find

Expected outcome: Claude should describe your project structure accurately. If it gets things wrong, correct it—this helps Claude learn.

Verify Claude's understanding:

Based on what you found, what type of project is this?
What framework or technology stack is used?

8.2 Understanding Architecture

Ask Claude to identify architectural patterns:

Analyze the architecture of this project:
1. What architectural pattern does it follow? (MVC, Clean Architecture, etc.)
2. What are the main layers and their responsibilities?
3. How is the code organized into modules/domains?
4. What design patterns do you see being used?

Verify with specific questions:

Show me an example of how a request flows through the system,
from entry point to database and back.

If Claude's analysis is accurate, great! If not, correct it:

Actually, this project uses Clean Architecture with these layers:
- Domain (src/Domain/)
- Application (src/Application/)
- Infrastructure (src/Infrastructure/)
- Presentation (src/Controller/)
Please update your understanding.

8.3 Discovering Business Logic

Help Claude understand what your project actually does:

What are the main business domains or features in this codebase?
List the core entities and explain their relationships.

Use specialized agents:

@database-architect
Analyze the database schema in this project.
What are the main entities, their relationships, and any patterns you notice?

@api-designer
Review the API endpoints in this project.
What resources are exposed? What patterns are used?

8.4 Documenting Context

You have two options to configure the project context:

Option A: Interactive Setup (Recommended)

Use the built-in command to auto-detect your stack and answer targeted questions:

/common:setup-project-context

The command will analyze your existing codebase, detect technologies, and ask only for missing information.

Option B: Manual Configuration

Create or update the project context file manually:

nano .claude/rules/00-project-context.md

Fill in the template with what you've discovered:

## Project Overview
- **Name**: [Your project name]
- **Description**: [What Claude learned + your additions]
- **Domain**: [e.g., E-commerce, Healthcare, FinTech]

## Architecture
- **Pattern**: [What Claude identified]
- **Layers**: [List them]
- **Key Directories**:
  - `src/Domain/` - Business logic and entities
  - `src/Application/` - Use cases and services
  - [etc.]

## Business Context
- **Main Entities**: [List core domain objects]
- **Key Workflows**: [Describe main user journeys]
- **External Integrations**: [APIs, services you connect to]

## Development Conventions
- **Testing**: [Your testing approach]
- **Code Style**: [Your standards]
- **Git Workflow**: [Your branching strategy]

## Important Notes for AI
- [Anything Claude should always remember]
- [Pitfalls to avoid]
- [Special considerations]

Save and verify Claude sees it:

Read the project context file and summarize what you understand
about this project now.

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9. Your First Modification

Now let's make your first AI-assisted change and push it.

9.1 Choose a Simple Task

Good first tasks:

• [ ] Add a missing unit test
• [ ] Fix a small bug
• [ ] Add documentation to a function
• [ ] Refactor a method for clarity
• [ ] Add input validation

Avoid for first task:

• Large features
• Critical security changes
• Database migrations
• Breaking API changes

9.2 Let Claude Analyze

Ask Claude to analyze before making changes:

I want to [describe your task].

Before making any changes:
1. Analyze the relevant code
2. Explain your approach
3. List the files you'll modify
4. Describe the tests you'll add or update

Review Claude's plan carefully. Ask questions:

Why did you choose this approach?
Are there any risks with this change?
What tests will verify this works?

9.3 Implement the Change

Once you're satisfied with the plan:

Go ahead and implement this change following TDD:
1. First write/update the tests
2. Then implement the code
3. Run the tests to verify

9.4 Review and Commit

Before committing, run quality checks:

/common:pre-commit-check

Review all changes:

git diff
git status

If everything looks good:

# Stage changes
git add .

# Commit with descriptive message
git commit -m "feat: [describe what you did]

- [bullet point of change]
- [another change]
- Added tests for [feature]

Co-Authored-By: Claude <noreply@anthropic.com>"

9.5 Push Your Changes

# Push to remote
git push origin main

If your CI/CD runs, verify it passes:

# Check CI status (if using GitHub)
gh run list --limit 1

Congratulations! You've made your first AI-assisted modification.

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10. Team Onboarding

Share Claude-Craft with your team.

Commit the Configuration

# Add Claude-Craft files to git
git add .claude/

# Commit
git commit -m "feat: add Claude-Craft AI development configuration

- Added rules for [your tech stack]
- Configured project context
- Added agents and commands"

# Push
git push origin main

Notify Your Team

Create a brief guide for teammates:

## Using Claude-Craft in This Project

1. Install Claude Code: [link]
2. Pull latest changes: `git pull`
3. Launch in project: `cd project && claude`

### Quick Commands
- `/common:pre-commit-check` - Run before committing
- `@tdd-coach` - Get help with tests
- `@{tech}-reviewer` - Code review

### Project Context
Our AI assistant understands:
- [Architecture patterns we use]
- [Coding conventions]
- [Business domain]

Team Demo

Consider running a short demo:

1. Show Claude exploring the codebase
2. Demonstrate a simple task
3. Show the pre-commit workflow
4. Answer questions

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11. Migration from Other AI Tools

If you're using other AI coding tools, migrate their configurations.

From Cursor Rules (.cursorrules)

# Check if you have Cursor rules
cat .cursorrules 2>/dev/null

Migration:

1. Open .cursorrules
2. Copy relevant rules
3. Add to .claude/rules/90-migrated-cursor-rules.md
4. Adapt format to Claude-Craft style

From GitHub Copilot Instructions

# Check for Copilot instructions
cat .github/copilot-instructions.md 2>/dev/null

Migration:

1. Open the Copilot instructions
2. Extract coding guidelines
3. Add to project context or custom rules

From Other Claude Configurations

If you have a root CLAUDE.md:

# Review existing config
cat CLAUDE.md 2>/dev/null

Migration:

1. Compare with new .claude/CLAUDE.md
2. Merge unique content
3. Keep root CLAUDE.md if it has project documentation
4. Remove if it's redundant with .claude/

Migration Mapping Table

Old Location	Claude-Craft Location
.cursorrules	.claude/rules/90-custom.md
.github/copilot-instructions.md	.claude/rules/00-project-context.md
CLAUDE.md (root)	.claude/CLAUDE.md
Custom prompts	.claude/commands/custom/

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12. Troubleshooting

Installation Issues

Problem: "Directory already exists" error

# Solution: Use force flag
npx @the-bearded-bear/claude-craft install . --tech=symfony --force

Problem: "Permission denied"

# Solution: Check ownership
ls -la .claude/
# Fix permissions
chmod -R 755 .claude/

Problem: "CLAUDE.md not found" after install

# Solution: Re-run installation
npx @the-bearded-bear/claude-craft install . --tech=symfony --lang=en

Claude Understanding Issues

Problem: Claude doesn't understand my project structure

Solution: Be explicit in your context file and during conversation:

This project uses [specific pattern]. The main source code is in [directory].
When I ask about [domain term], I mean [explanation].

Problem: Claude suggests wrong patterns

Solution: Correct and reinforce:

We don't use [pattern] in this project. We use [correct pattern] because [reason].
Please remember this for future suggestions.

Problem: Claude forgets context between sessions

Solution: Ensure 00-project-context.md is comprehensive. Key information should be in files, not just conversation.

Rollback

If you need to undo the installation:

# Remove Claude-Craft files
rm -rf .claude/

# Restore from backup branch
git checkout backup/before-claude-craft -- .

# Or hard reset
git checkout backup/before-claude-craft

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Summary

You've successfully:

• [x] Backed up your project
• [x] Installed Claude-Craft safely
• [x] Made Claude understand your codebase
• [x] Made your first AI-assisted modification
• [x] Pushed changes to your repository
• [x] Prepared for team onboarding

What's Next?

Task	Guide
Learn the full TDD workflow	Feature Development
Debug issues effectively	Bug Fixing
Manage your backlog with AI	Backlog Management
Explore advanced tools	Tools Reference

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