Chapter 3: Installation Modes and Rules Strategy

Welcome to Chapter 3: Installation Modes and Rules Strategy. In this part of Everything Claude Code Tutorial: Production Configuration Patterns for Claude Code, you will build an intuitive mental model first, then move into concrete implementation details and practical production tradeoffs.

This chapter covers installation choices and language-rule management.

Learning Goals

• choose plugin install vs manual install intentionally
• configure common plus language-specific rules safely
• avoid rule bloat across mixed-language projects
• maintain consistent setup across contributors

Installation Paths

• plugin install (recommended for most users)
• manual copy/sync of components (advanced customization)

Rules Strategy

• always install common rules
• add only language sets you actively use
• version rule sets with project onboarding docs

Source References

• README Installation
• Rules README
• Plugin Manifest Notes

Summary

You now have a reproducible installation strategy.

Next: Chapter 4: Agents, Skills, and Command Orchestration

Source Code Walkthrough

scripts/claw.js

The loadECCContext function in scripts/claw.js handles a key part of this chapter's functionality:

}

function loadECCContext(skillList) {
  const requested = normalizeSkillList(skillList !== undefined ? skillList : process.env.CLAW_SKILLS || '');
  if (requested.length === 0) return '';

  const chunks = [];
  for (const name of requested) {
    const skillPath = path.join(process.cwd(), 'skills', name, 'SKILL.md');
    try {
      chunks.push(fs.readFileSync(skillPath, 'utf8'));
    } catch {
      // Skip missing skills silently to keep REPL usable.
    }
  }

  return chunks.join('\n\n');
}

function buildPrompt(systemPrompt, history, userMessage) {
  const parts = [];
  if (systemPrompt) parts.push(`=== SYSTEM CONTEXT ===\n${systemPrompt}\n`);
  if (history) parts.push(`=== CONVERSATION HISTORY ===\n${history}\n`);
  parts.push(`=== USER MESSAGE ===\n${userMessage}`);
  return parts.join('\n');
}

function askClaude(systemPrompt, history, userMessage, model) {
  const fullPrompt = buildPrompt(systemPrompt, history, userMessage);
  const args = [];
  if (model) {
    args.push('--model', model);

This function is important because it defines how Everything Claude Code Tutorial: Production Configuration Patterns for Claude Code implements the patterns covered in this chapter.

scripts/claw.js

The buildPrompt function in scripts/claw.js handles a key part of this chapter's functionality:

}

function buildPrompt(systemPrompt, history, userMessage) {
  const parts = [];
  if (systemPrompt) parts.push(`=== SYSTEM CONTEXT ===\n${systemPrompt}\n`);
  if (history) parts.push(`=== CONVERSATION HISTORY ===\n${history}\n`);
  parts.push(`=== USER MESSAGE ===\n${userMessage}`);
  return parts.join('\n');
}

function askClaude(systemPrompt, history, userMessage, model) {
  const fullPrompt = buildPrompt(systemPrompt, history, userMessage);
  const args = [];
  if (model) {
    args.push('--model', model);
  }
  args.push('-p', fullPrompt);

  const result = spawnSync('claude', args, {
    encoding: 'utf8',
    stdio: ['pipe', 'pipe', 'pipe'],
    env: { ...process.env, CLAUDECODE: '' },
    timeout: 300000,
  });

  if (result.error) {
    return `[Error: ${result.error.message}]`;
  }

  if (result.status !== 0 && result.stderr) {
    return `[Error: claude exited with code ${result.status}: ${result.stderr.trim()}]`;
  }

This function is important because it defines how Everything Claude Code Tutorial: Production Configuration Patterns for Claude Code implements the patterns covered in this chapter.

scripts/claw.js

The askClaude function in scripts/claw.js handles a key part of this chapter's functionality:

}

function askClaude(systemPrompt, history, userMessage, model) {
  const fullPrompt = buildPrompt(systemPrompt, history, userMessage);
  const args = [];
  if (model) {
    args.push('--model', model);
  }
  args.push('-p', fullPrompt);

  const result = spawnSync('claude', args, {
    encoding: 'utf8',
    stdio: ['pipe', 'pipe', 'pipe'],
    env: { ...process.env, CLAUDECODE: '' },
    timeout: 300000,
  });

  if (result.error) {
    return `[Error: ${result.error.message}]`;
  }

  if (result.status !== 0 && result.stderr) {
    return `[Error: claude exited with code ${result.status}: ${result.stderr.trim()}]`;
  }

  return (result.stdout || '').trim();
}

function parseTurns(history) {
  const turns = [];
  const regex = /### \[([^\]]+)\] ([^\n]+)\n([\s\S]*?)\n---\n/g;
  let match;

This function is important because it defines how Everything Claude Code Tutorial: Production Configuration Patterns for Claude Code implements the patterns covered in this chapter.

scripts/claw.js

The parseTurns function in scripts/claw.js handles a key part of this chapter's functionality:

}

function parseTurns(history) {
  const turns = [];
  const regex = /### \[([^\]]+)\] ([^\n]+)\n([\s\S]*?)\n---\n/g;
  let match;
  while ((match = regex.exec(history)) !== null) {
    turns.push({ timestamp: match[1], role: match[2], content: match[3] });
  }
  return turns;
}

function estimateTokenCount(text) {
  return Math.ceil((text || '').length / 4);
}

function getSessionMetrics(filePath) {
  const history = loadHistory(filePath);
  const turns = parseTurns(history);
  const charCount = history.length;
  const tokenEstimate = estimateTokenCount(history);
  const userTurns = turns.filter(t => t.role === 'User').length;
  const assistantTurns = turns.filter(t => t.role === 'Assistant').length;

  return {
    turns: turns.length,
    userTurns,
    assistantTurns,
    charCount,
    tokenEstimate,
  };
}

This function is important because it defines how Everything Claude Code Tutorial: Production Configuration Patterns for Claude Code implements the patterns covered in this chapter.

How These Components Connect

flowchart TD
    A[loadECCContext]
    B[buildPrompt]
    C[askClaude]
    D[parseTurns]
    E[estimateTokenCount]
    A --> B
    B --> C
    C --> D
    D --> E