Demo Working with Claude Code Agents

cwd: /Users/jeremy/Repos/project/Express-login-demo

> /agents

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› Create new agent

No agents found. Create specialized subagents that Claude can delegate to.
Each subagent has its own context window, custom system prompt, and specific tools.
Try creating: Code Reviewer, Code Simplifier, Security Reviewer, Tech Lead, or UX Reviewer.

Built-in (always available):
general-purpose · sonnet
statusline-setup · sonnet
output-style-setup · sonnet

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cwd: /Users/jeremy/Repos/project/Express-login-demo

> /agents

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Creation method

> 1. Generate with Claude (recommended)
2. Manual configuration

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cwd: /Users/jeremy/Repos/project/Express-login-demo

> /agents

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cwd: /Users/jeremy/Repos/project/Express-login-demo

> /agents

Create new agent
Select model
Model determines the agent's reasoning capabilities and speed.

  1. Sonnet           Balanced performance -- best for most agents
  2. Haiku            Fast and efficient for simple tasks
> 3. Inherit from parent  Use the same model as the main conversation

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Create new agent
Confirm and save

Name: code-readability-reviewer
Location: .claude/agents/code-readability-reviewer.md
Tools: Bash, Glob, Grep, LS, Read, WebFetch, TodoWrite, WebSearch, BashOutput, KillBash
Model: Inherit from parent

Description (tells Claude when to use this agent):

    Use this agent when you need to evaluate code for readability, variable naming conventions, and overall code clarity.

System prompt:

    You are a Senior Code Quality Specialist with expertise in software readability, maintainability, and naming conventions across multiple programming languages. Your primary focus is evaluating code for clarity, comprehensibility, and adherence to clean code principles.

Press s or Enter to save, e to save and edit

cwd: /Users/jeremy/Repos/project/Express-login-demo

> /agents

Agents
4 agents

Created agent: code-readability-reviewer

Create new agent

Project agents (/Users/jeremy/Repos/project/Express-login-demo/.claude/agents)
> code-readability-reviewer .inherit

Built-in agents (always available)
general-purpose · sonnet
statusline-setup · sonnet
output-style-setup · sonnet

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name: code-readability-reviewer
description: Use this agent when you need to evaluate code for readability, variable naming conventions, and overall code clarity.
tools: Bash, Glob, Grep, LS, Read, WebFetch, TodoWrite, WebSearch, BashOutput, KillBash
model: inherit
color: green

cwd: /Users/jeremy/Repos/project/Express-login-demo

> use the code-readability-reviewer agent to inspect auth.js and give me a report.

• I'll use the code-readability-reviewer agent to analyze the auth.js file and provide you with a readability report.

• code-readability-reviewer(Review auth.js readability)
  Done (2 tool uses · 12.1k tokens · 29.9s)

• The code-readability-reviewer agent has analyzed your auth.js file and provided a comprehensive readability report. Here are the key findings:

Overall Score: 8/10 - The code is well-structured with good naming conventions and follows Express.js patterns effectively.

Main Strengths:
 - Clear variable names like userQuery, isPasswordValid
 - Consistent camelCase naming
 - Proper separation of validation and business logic
 - Good security practices (parameterized queries, password hashing)

Key Areas for Improvement:
 1. Extract database error handling – Error codes (e.g., '28P01', '3D000') should be defined as constants.
 2. Function length – The main handler is 78 lines and could be broken into smaller, testable functions.
 3. Magic strings – Move SQL queries and error code strings into constants.

Recommended Priority Fixes:
 - Define constants for database error codes
 - Extract the authentication logic into a separate function
 - Move hardcoded SQL query to a constant

The code follows security best practices but would benefit from better organization and consistent constant definitions for maintainability.

// routes/auth.js
const express = require('express');
const { body, validationResult } = require('express-validator');
const pool = require('../config/database'); // assume configured pg pool
const router = express.Router();

router.post(
  '/login',
  [
    body('email').isEmail().withMessage('Please provide a valid email address').normalizeEmail(),
    body('password').isLength({ min: 8 }).withMessage('Password must be at least 8 characters long')
  ],
  async (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({ error: 'Validation failed', details: errors.array() });
    }

    try {
      const { email, password } = req.body;
      // Extracted authentication logic would go here (e.g., verify user and password)
      // Example: const user = await findUserByEmail(email);
      // if (!user || !verifyPassword(password, user.hash)) return res.status(401).send('Unauthorized');

      res.status(200).json({ message: 'Login successful' });
    } catch (err) {
      console.error('Auth error:', err);
      res.status(500).json({ error: 'Internal server error' });
    }
  }
);

module.exports = router;

import asyncio
from claude_code_sdk import ClaudeSDKClient, ClaudeCodeOptions

async def main():
    async with ClaudeSDKClient(
        options=ClaudeCodeOptions(
            system_prompt="You are an SRE agent. Diagnose incidents step-by-step and propose safe fixes.",
            allowed_tools=["Read", "Grep", "Bash"],  # fine-grained control
            max_turns=4
        )
    ) as client:
        await client.query("API error rates just spiked in payments — investigate and propose fixes.")
        async for msg in client.receive_response():
            if hasattr(msg, "content"):
                for block in msg.content:
                    if hasattr(block, "text"):
                        print(block.text, end="")

asyncio.run(main())

---
name: code-readability-reviewer
description: Use this agent when you need to evaluate code for readability, variable naming conventions, and overall code clarity.
tools: Bash, Glob, Grep, LS, Read, WebFetch, TodoWrite, WebSearch, BashOutput, KillBash
model: inherit
color: green
---

# Claude 4 Models
"claude-opus-4-1-20250505"
"claude-opus-4-1"
"claude-opus-4-20250514"
"claude-opus-4-0"
"claude-sonnet-4-20250514"
"claude-sonnet-4-0"

# Claude 3.7 Models
"claude-3-7-sonnet-20250219"
"claude-3-7-sonnet-latest"

# Claude 3.5 Models
"claude-3-5-haiku-20241022"
"claude-3-5-haiku-latest"

// Go (illustrative)
package main

import (
	"context"
	"fmt"
	"github.com/anthropics/anthropic-sdk-go"
	"github.com/anthropics/anthropic-sdk-go/option"
)

func main() {
	client := anthropic.NewClient(option.WithAPIKey("my-anthropic-api-key"))
	msg, err := client.Messages.New(context.Background(), anthropic.MessageNewParams{
		Model:     anthropic.ModelClaudeSonnet4_0,
		MaxTokens: 1024,
		Messages: []anthropic.Message{{
			Role:    "user",
			Content: "Hello, Claude",
		}},
	})
	if err != nil {
		panic(err)
	}
	fmt.Println(msg.Content)
}

# Ruby (illustrative)
require "anthropic"

anthropic = Anthropic::Client.new(api_key: "my_api_key") # or ENV["ANTHROPIC_API_KEY"]

message = anthropic.messages.create(
  max_tokens: 1024,
  messages: [{ role: "user", content: "Hello, Claude" }],
  model: "claude-sonnet-4-20250514"
)

puts(message.content)