OpenAI Codex Code Generation Cheat Sheet

Overview

OpenAI Codex is a powerful AI system that translates natural language to code, capable of understanding and generating code in dozens of programming languages. Built on GPT-3 architecture and trained on billions of lines of public code, Codex powers GitHub Copilot and provides advanced code completion, generation, and explanation capabilities. It excels at understanding context, generating functions, classes, and entire applications from natural language descriptions.

⚠️ Note: OpenAI Codex API was deprecated in March 2023. This guide covers historical usage and migration to GPT-3.5/GPT-4 models for code generation tasks.

Migration to Current Models

GPT-3.5/GPT-4 for Code Generation

python

# Install OpenAI Python library
pip install openai

# Basic setup for code generation with current models
import openai

openai.api_key = "your-api-key-here"

# Use GPT-3.5-turbo or GPT-4 for code generation
response = openai.ChatCompletion.create(
    model="gpt-3.5-turbo",  # or "gpt-4"
    messages=[
        {
            "role": "system", 
            "content": "You are an expert programmer. Generate clean, efficient, and well-documented code."
        },
        {
            "role": "user", 
            "content": "Write a Python function to implement binary search"
        }
    ],
    max_tokens=1000,
    temperature=0.1  # Lower temperature for more deterministic code
)

print(response.choices[0].message.content)

Legacy Codex API Usage (Historical Reference)

python

# Historical Codex API usage (deprecated)
import openai

openai.api_key = "your-api-key-here"

# Codex completion (no longer available)
response = openai.Completion.create(
    engine="code-davinci-002",  # Deprecated
    prompt="# Function to calculate factorial\ndef factorial(n):",
    max_tokens=150,
    temperature=0,
    stop=["#", "\n\n"]
)

print(response.choices[0].text)

Modern Code Generation Setup

Python SDK Configuration

python

#!/usr/bin/env python3
# modern-codex-replacement.py

import openai
import os
import json
from typing import List, Dict, Optional
from datetime import datetime

class ModernCodeGenerator:
    def __init__(self, api_key: str = None):
        self.client = openai.OpenAI(
            api_key=api_key or os.getenv("OPENAI_API_KEY")
        )
        self.conversation_history = []
    
    def generate_code(self, prompt: str, language: str = "python", 
                     model: str = "gpt-3.5-turbo") -> str:
        """Generate code using modern OpenAI models"""
        
        system_prompt = f"""
You are an expert {language} developer. Generate clean, efficient, 
and well-documented code that follows best practices. Include:
- Proper error handling
- Type hints (where applicable)
- Comprehensive docstrings
- Security considerations
- Performance optimizations
"""
        
        try:
            response = self.client.chat.completions.create(
                model=model,
                messages=[
                    {"role": "system", "content": system_prompt},
                    {"role": "user", "content": prompt}
                ],
                max_tokens=2000,
                temperature=0.1,
                top_p=1.0,
                frequency_penalty=0.0,
                presence_penalty=0.0
            )
            
            generated_code = response.choices[0].message.content
            
            # Store in conversation history
            self.conversation_history.append({
                "prompt": prompt,
                "language": language,
                "model": model,
                "response": generated_code,
                "timestamp": datetime.now().isoformat()
            })
            
            return generated_code
        
        except Exception as e:
            return f"Error generating code: {e}"
    
    def complete_code(self, partial_code: str, language: str = "python",
                     model: str = "gpt-3.5-turbo") -> str:
        """Complete partial code snippets"""
        
        prompt = f"""
Complete this {language} code snippet. Provide only the missing parts:

```{language}
{partial_code}

Continue the code logically and maintain the existing style and patterns. """

    try:
        response = self.client.chat.completions.create(
            model=model,
            messages=[
                {"role": "user", "content": prompt}
            ],
            max_tokens=1000,
            temperature=0.1
        )
        
        return response.choices[0].message.content
    
    except Exception as e:
        return f"Error completing code: {e}"

def explain_code(self, code: str, language: str = "python") -> str:
    """Explain existing code"""
    
    prompt = f"""

Explain this {language} code in detail:

{code}

Provide:

High-level overview
Line-by-line explanation of complex parts
Purpose and functionality

Potential improvements """

 try:
     response = self.client.chat.completions.create(
         model="gpt-3.5-turbo",
         messages=[
             {"role": "user", "content": prompt}
         ],
         max_tokens=1500,
         temperature=0.1
     )
     
     return response.choices[0].message.content
 
 except Exception as e:
     return f"Error explaining code: {e}"

def fix_code(self, buggy_code: str, error_message: str = None, language: str = "python") -> str: """Fix buggy code"""

 prompt = f"""

Fix this {language} code that has issues:

{buggy_code}

"""

    if error_message:
        prompt += f"\nError message: {error_message}"
    
    prompt += """

Provide:

Corrected code
Explanation of what was wrong

Prevention strategies for similar issues """

 try:
     response = self.client.chat.completions.create(
         model="gpt-3.5-turbo",
         messages=[
             {"role": "user", "content": prompt}
         ],
         max_tokens=1500,
         temperature=0.1
     )
     
     return response.choices[0].message.content
 
 except Exception as e:
     return f"Error fixing code: {e}"

def generate_tests(self, code: str, language: str = "python") -> str: """Generate test cases for code"""

 test_frameworks = {
     "python": "pytest",
     "javascript": "jest",
     "java": "junit",
     "csharp": "nunit",
     "go": "testing package"
 }
 
 framework = test_frameworks.get(language, "appropriate testing framework")
 
 prompt = f"""

Generate comprehensive test cases for this {language} code using {framework}:

{code}

Include:

Unit tests for all functions/methods
Edge cases and boundary conditions
Error handling tests
Mock objects where needed

Test data setup and teardown """

 try:
     response = self.client.chat.completions.create(
         model="gpt-3.5-turbo",
         messages=[
             {"role": "user", "content": prompt}
         ],
         max_tokens=2000,
         temperature=0.1
     )
     
     return response.choices[0].message.content
 
 except Exception as e:
     return f"Error generating tests: {e}"

Example usage

def main(): generator = ModernCodeGenerator()

# Generate a REST API client
prompt = """

Create a Python class for a REST API client that handles:

GET, POST, PUT, DELETE requests
Authentication with API keys
Retry logic with exponential backoff
Rate limiting
Response caching
Comprehensive error handling """
code = generator.generate_code(prompt, "python", "gpt-4") print("Generated Code:") print("=" * 50) print(code)

if name == "main": main()


## Language-Specific Code Generation

### Python Development
```python
# Python-specific code generation examples

# Data science and machine learning
prompt = """
Create a Python script for machine learning that:
- Loads data from CSV files
- Performs data preprocessing and feature engineering
- Implements multiple ML models (Random Forest, SVM, Neural Network)
- Evaluates models with cross-validation
- Visualizes results and feature importance
- Saves the best model for deployment
"""

# Web development with FastAPI
prompt = """
Build a FastAPI application that:
- Implements user authentication with JWT
- Uses SQLAlchemy for database operations
- Includes CRUD operations for a blog system
- Implements rate limiting and CORS
- Includes comprehensive error handling
- Provides OpenAPI documentation
"""

# DevOps automation
prompt = """
Create a Python automation script that:
- Manages Docker containers
- Deploys applications to Kubernetes
- Monitors application health
- Sends alerts via Slack/email
- Implements rollback functionality
- Logs all operations
"""

JavaScript/TypeScript Development

javascript

// JavaScript/TypeScript code generation

// React component with hooks
const prompt = `
Create a React TypeScript component that:
- Implements a data table with sorting, filtering, and pagination
- Uses React Query for data fetching
- Includes proper TypeScript interfaces
- Implements accessibility features (ARIA labels, keyboard navigation)
- Uses CSS modules for styling
- Includes comprehensive error boundaries
`;

// Node.js microservice
const prompt = `
Build a Node.js microservice with TypeScript that:
- Implements GraphQL API with Apollo Server
- Uses Prisma for database operations
- Includes authentication middleware
- Implements caching with Redis
- Uses Winston for logging
- Includes health check endpoints
`;

// Frontend build optimization
const prompt = `
Create a Webpack configuration that:
- Optimizes bundle size with code splitting
- Implements tree shaking
- Uses service workers for caching
- Includes source maps for debugging
- Supports hot module replacement
- Generates performance reports
`;

Go Development

// Go-specific code generation

// Microservice with gRPC
prompt := `
Create a Go microservice that:
- Implements gRPC server with protocol buffers
- Uses GORM for database operations
- Includes middleware for logging and authentication
- Implements graceful shutdown
- Uses Prometheus for metrics
- Includes comprehensive error handling
`

// Concurrent data processing
prompt := `
Implement a Go program that:
- Processes large datasets concurrently
- Uses worker pools with goroutines
- Implements backpressure handling
- Includes progress monitoring
- Uses channels for communication
- Handles graceful cancellation
`

Advanced Code Generation Techniques

Context-Aware Generation

python

#!/usr/bin/env python3
# context-aware-generation.py

import openai
import os
import ast
from typing import List, Dict

class ContextAwareGenerator:
    def __init__(self):
        self.client = openai.OpenAI(api_key=os.getenv("OPENAI_API_KEY"))
        self.project_context = {}
    
    def analyze_codebase(self, directory: str) -> Dict:
        """Analyze existing codebase for context"""
        
        context = {
            "languages": set(),
            "frameworks": set(),
            "patterns": set(),
            "dependencies": set(),
            "file_structure": {}
        }
        
        # Analyze Python files
        for root, dirs, files in os.walk(directory):
            for file in files:
                if file.endswith('.py'):
                    file_path = os.path.join(root, file)
                    try:
                        with open(file_path, 'r') as f:
                            content = f.read()
                        
                        # Parse AST for imports and patterns
                        tree = ast.parse(content)
                        
                        for node in ast.walk(tree):
                            if isinstance(node, ast.Import):
                                for alias in node.names:
                                    context["dependencies"].add(alias.name)
                            elif isinstance(node, ast.ImportFrom):
                                if node.module:
                                    context["dependencies"].add(node.module)
                        
                        context["languages"].add("python")
                        
                        # Detect frameworks
                        if "flask" in content.lower():
                            context["frameworks"].add("Flask")
                        if "django" in content.lower():
                            context["frameworks"].add("Django")
                        if "fastapi" in content.lower():
                            context["frameworks"].add("FastAPI")
                    
                    except Exception as e:
                        print(f"Error analyzing {file_path}: {e}")
        
        self.project_context = context
        return context
    
    def generate_with_context(self, prompt: str, language: str = "python") -> str:
        """Generate code with project context"""
        
        context_info = ""
        if self.project_context:
            context_info = f"""
Project Context:
- Languages: {', '.join(self.project_context.get('languages', []))}
- Frameworks: {', '.join(self.project_context.get('frameworks', []))}
- Key Dependencies: {', '.join(list(self.project_context.get('dependencies', []))[:10])}

Please generate code that fits with this existing codebase.
"""
        
        full_prompt = f"{context_info}\n\nRequest: {prompt}"
        
        try:
            response = self.client.chat.completions.create(
                model="gpt-4",
                messages=[
                    {
                        "role": "system",
                        "content": f"You are an expert {language} developer working on an existing project. Generate code that integrates well with the existing codebase."
                    },
                    {"role": "user", "content": full_prompt}
                ],
                max_tokens=2000,
                temperature=0.1
            )
            
            return response.choices[0].message.content
        
        except Exception as e:
            return f"Error generating contextual code: {e}"
    
    def suggest_refactoring(self, code: str, language: str = "python") -> str:
        """Suggest refactoring based on project context"""
        
        context_info = ""
        if self.project_context:
            frameworks = ', '.join(self.project_context.get('frameworks', []))
            if frameworks:
                context_info = f"This project uses {frameworks}. "
        
        prompt = f"""
{context_info}Analyze this {language} code and suggest refactoring:

```{language}
{code}

Consider:

Code patterns used in the project
Framework-specific best practices
Performance optimizations
Maintainability improvements

Security enhancements """

 try:
     response = self.client.chat.completions.create(
         model="gpt-4",
         messages=[
             {"role": "user", "content": prompt}
         ],
         max_tokens=2000,
         temperature=0.1
     )
     
     return response.choices[0].message.content
 
 except Exception as e:
     return f"Error suggesting refactoring: {e}"

def main(): generator = ContextAwareGenerator()

# Analyze current project
context = generator.analyze_codebase(".")
print("Project Context:")
for key, value in context.items():
    print(f"  {key}: {value}")

# Generate code with context
prompt = "Create a new API endpoint for user management"
code = generator.generate_with_context(prompt)
print("\nGenerated Code:")
print("=" * 50)
print(code)

if name == "main": main()


### Multi-Step Code Generation
```python
#!/usr/bin/env python3
# multi-step-generation.py

import openai
import os
from typing import List, Dict

class MultiStepGenerator:
    def __init__(self):
        self.client = openai.OpenAI(api_key=os.getenv("OPENAI_API_KEY"))
        self.generation_steps = []
    
    def plan_implementation(self, requirement: str) -> List[str]:
        """Break down complex requirements into implementation steps"""
        
        prompt = f"""
Break down this software requirement into detailed implementation steps:

Requirement: {requirement}

Provide a step-by-step implementation plan with:
1. Architecture decisions
2. Component breakdown
3. Implementation order
4. Dependencies between components
5. Testing strategy

Format as a numbered list of specific, actionable steps.
"""
        
        try:
            response = self.client.chat.completions.create(
                model="gpt-4",
                messages=[
                    {"role": "user", "content": prompt}
                ],
                max_tokens=1500,
                temperature=0.1
            )
            
            plan = response.choices[0].message.content
            
            # Extract steps (simple parsing)
            steps = []
            for line in plan.split('\n'):
                if line.strip() and (line.strip()[0].isdigit() or line.strip().startswith('-')):
                    steps.append(line.strip())
            
            self.generation_steps = steps
            return steps
        
        except Exception as e:
            return [f"Error creating plan: {e}"]
    
    def implement_step(self, step: str, previous_code: str = "", 
                      language: str = "python") -> str:
        """Implement a specific step"""
        
        context = ""
        if previous_code:
            context = f"""
Previous implementation:
```{language}
{previous_code}

Build upon this existing code. """

    prompt = f"""

Implement this specific step:

Provide complete, working {language} code that:

Implements only this step
Integrates with previous code (if any)
Includes proper error handling
Follows best practices

Includes comments explaining the implementation """

  try:
      response = self.client.chat.completions.create(
          model="gpt-4",
          messages=[
              {"role": "user", "content": prompt}
          ],
          max_tokens=2000,
          temperature=0.1
      )
      
      return response.choices[0].message.content
  
  except Exception as e:
      return f"Error implementing step: {e}"

def generate_complete_solution(self, requirement: str, language: str = "python") -> Dict: """Generate complete solution using multi-step approach"""

  print(f"Planning implementation for: {requirement}")
  
  # Step 1: Create implementation plan
  steps = self.plan_implementation(requirement)
  
  print(f"Implementation plan created with {len(steps)} steps")
  
  # Step 2: Implement each step
  complete_code = ""
  step_implementations = []
  
  for i, step in enumerate(steps, 1):
      print(f"Implementing step {i}/{len(steps)}: {step[:50]}...")
      
      step_code = self.implement_step(step, complete_code, language)
      step_implementations.append({
          "step": step,
          "code": step_code,
          "step_number": i
      })
      
      # Accumulate code for next step
      complete_code += f"\n\n# Step {i}: {step}\n{step_code}"
  
  # Step 3: Review and optimize complete solution
  optimized_code = self.optimize_complete_solution(complete_code, language)
  
  return {
      "requirement": requirement,
      "language": language,
      "plan": steps,
      "step_implementations": step_implementations,
      "complete_code": complete_code,
      "optimized_code": optimized_code
  }

def optimize_complete_solution(self, code: str, language: str = "python") -> str: """Optimize the complete solution"""

  prompt = f"""

Review and optimize this complete {language} solution:

{code}

Optimize for:

Code organization and structure
Performance improvements
Error handling consistency
Code reuse and DRY principles
Documentation and comments
Security considerations

Provide the optimized version with explanations of changes. """

    try:
        response = self.client.chat.completions.create(
            model="gpt-4",
            messages=[
                {"role": "user", "content": prompt}
            ],
            max_tokens=3000,
            temperature=0.1
        )
        
        return response.choices[0].message.content
    
    except Exception as e:
        return f"Error optimizing solution: {e}"

def main(): generator = MultiStepGenerator()

requirement = """

Create a web scraping system that:

Scrapes product data from multiple e-commerce sites
Handles rate limiting and anti-bot measures
Stores data in a database
Provides a REST API to query the data
Includes monitoring and alerting
Supports distributed scraping across multiple workers """
solution = generator.generate_complete_solution(requirement, "python")
print("\nImplementation Plan:") print("=" * 50) for i, step in enumerate(solution["plan"], 1): print(f"{i}. {step}")
print(f"\nComplete solution generated with {len(solution['step_implementations'])} steps") print("Check the generated files for detailed implementation.")
Save results
with open("multi_step_solution.py", "w") as f: f.write(solution["optimized_code"])
print("Optimized solution saved to: multi_step_solution.py")

if name == "main": main()


## IDE and Editor Integration

### VS Code Integration
```json
// VS Code settings for modern code generation
{
  "openai.apiKey": "${env:OPENAI_API_KEY}",
  "openai.model": "gpt-3.5-turbo",
  "openai.maxTokens": 1000,
  "openai.temperature": 0.1,
  "openai.codeCompletion": true,
  "openai.codeExplanation": true,
  "openai.codeGeneration": true,
  "openai.languages": [
    "python",
    "javascript",
    "typescript",
    "go",
    "java",
    "cpp",
    "csharp"
  ]
}

Vim/Neovim Plugin

lua

-- Neovim Lua configuration for code generation
local function generate_code()
  local prompt = vim.fn.input("Code generation prompt: ")
  if prompt == "" then
    return
  end
  
  local language = vim.bo.filetype
  local api_key = os.getenv("OPENAI_API_KEY")
  
  if not api_key then
    print("Error: OPENAI_API_KEY not set")
    return
  end
  
  -- Call Python script for code generation
  local cmd = string.format(
    "python3 -c \"import openai; openai.api_key='%s'; response=openai.ChatCompletion.create(model='gpt-3.5-turbo', messages=[{'role': 'user', 'content': 'Generate %s code: %s'}], max_tokens=1000, temperature=0.1); print(response.choices[0].message.content)\"",
    api_key, language, prompt
  )
  
  local output = vim.fn.system(cmd)
  
  -- Insert generated code at cursor
  local lines = vim.split(output, "\n")
  vim.api.nvim_put(lines, "l", true, true)
end

-- Key mapping
vim.keymap.set("n", "<leader>cg", generate_code, { desc = "Generate code" })

Emacs Integration

elisp

;; Emacs Lisp configuration for code generation
(defun openai-generate-code (prompt)
  "Generate code using OpenAI API"
  (interactive "sCode generation prompt: ")
  (let* ((api-key (getenv "OPENAI_API_KEY"))
         (language (file-name-extension (buffer-file-name)))
         (python-script (format 
           "import openai; openai.api_key='%s'; response=openai.ChatCompletion.create(model='gpt-3.5-turbo', messages=[{'role': 'user', 'content': 'Generate %s code: %s'}], max_tokens=1000, temperature=0.1); print(response.choices[0].message.content)"
           api-key language prompt)))
    (if api-key
        (let ((output (shell-command-to-string (format "python3 -c \"%s\"" python-script))))
          (insert output))
      (message "Error: OPENAI_API_KEY not set"))))

;; Key binding
(global-set-key (kbd "C-c g") 'openai-generate-code)

Command Line Tools

CLI Code Generator

bash

#!/bin/bash
# codegen-cli.sh - Command line code generator

OPENAI_API_KEY="${OPENAI_API_KEY}"
MODEL="gpt-3.5-turbo"
MAX_TOKENS=1500
TEMPERATURE=0.1

if [ -z "$OPENAI_API_KEY" ]; then
    echo "Error: OPENAI_API_KEY environment variable not set"
    exit 1
fi

show_help() {
    echo "Code Generation CLI Tool"
    echo "Usage:"
    echo "  codegen-cli.sh generate <language> <prompt>  - Generate code"
    echo "  codegen-cli.sh complete <file>               - Complete code in file"
    echo "  codegen-cli.sh explain <file>                - Explain code in file"
    echo "  codegen-cli.sh fix <file> [error_message]    - Fix buggy code"
    echo "  codegen-cli.sh test <file>                   - Generate tests"
    echo ""
    echo "Examples:"
    echo "  codegen-cli.sh generate python 'Create a REST API client'"
    echo "  codegen-cli.sh complete main.py"
    echo "  codegen-cli.sh explain algorithm.py"
    echo ""
    echo "Environment variables:"
    echo "  OPENAI_API_KEY - Your OpenAI API key"
}

call_openai_api() {
    local system_prompt="$1"
    local user_prompt="$2"
    
    python3 << EOF
import openai
import json
import sys

openai.api_key = "$OPENAI_API_KEY"

try:
    response = openai.ChatCompletion.create(
        model="$MODEL",
        messages=[
            {"role": "system", "content": "$system_prompt"},
            {"role": "user", "content": "$user_prompt"}
        ],
        max_tokens=$MAX_TOKENS,
        temperature=$TEMPERATURE
    )
    
    print(response.choices[0].message.content)
    
except Exception as e:
    print(f"Error: {e}", file=sys.stderr)
    sys.exit(1)
EOF
}

case "$1" in
    "generate")
        if [ $# -lt 3 ]; then
            echo "Usage: codegen-cli.sh generate <language> <prompt>"
            exit 1
        fi
        
        language="$2"
        prompt="$3"
        
        system_prompt="You are an expert $language developer. Generate clean, efficient, and well-documented code."
        user_prompt="Generate $language code: $prompt"
        
        echo "Generating $language code..."
        echo "=========================="
        call_openai_api "$system_prompt" "$user_prompt"
        ;;
    
    "complete")
        if [ $# -lt 2 ]; then
            echo "Usage: codegen-cli.sh complete <file>"
            exit 1
        fi
        
        file="$2"
        
        if [ ! -f "$file" ]; then
            echo "Error: File $file not found"
            exit 1
        fi
        
        # Detect language from file extension
        extension="${file##*.}"
        case "$extension" in
            "py") language="python" ;;
            "js") language="javascript" ;;
            "ts") language="typescript" ;;
            "go") language="go" ;;
            "java") language="java" ;;
            *) language="unknown" ;;
        esac
        
        code_content=$(cat "$file")
        user_prompt="Complete this $language code:\n\n$code_content"
        
        echo "Completing code in $file..."
        echo "=========================="
        call_openai_api "You are an expert programmer. Complete the provided code." "$user_prompt"
        ;;
    
    "explain")
        if [ $# -lt 2 ]; then
            echo "Usage: codegen-cli.sh explain <file>"
            exit 1
        fi
        
        file="$2"
        
        if [ ! -f "$file" ]; then
            echo "Error: File $file not found"
            exit 1
        fi
        
        code_content=$(cat "$file")
        user_prompt="Explain this code in detail:\n\n$code_content"
        
        echo "Explaining code in $file..."
        echo "=========================="
        call_openai_api "You are an expert programmer. Explain code clearly and comprehensively." "$user_prompt"
        ;;
    
    "fix")
        if [ $# -lt 2 ]; then
            echo "Usage: codegen-cli.sh fix <file> [error_message]"
            exit 1
        fi
        
        file="$2"
        error_message="$3"
        
        if [ ! -f "$file" ]; then
            echo "Error: File $file not found"
            exit 1
        fi
        
        code_content=$(cat "$file")
        user_prompt="Fix this buggy code:\n\n$code_content"
        
        if [ -n "$error_message" ]; then
            user_prompt="$user_prompt\n\nError message: $error_message"
        fi
        
        echo "Fixing code in $file..."
        echo "======================"
        call_openai_api "You are an expert debugger. Fix code issues and explain the problems." "$user_prompt"
        ;;
    
    "test")
        if [ $# -lt 2 ]; then
            echo "Usage: codegen-cli.sh test <file>"
            exit 1
        fi
        
        file="$2"
        
        if [ ! -f "$file" ]; then
            echo "Error: File $file not found"
            exit 1
        fi
        
        code_content=$(cat "$file")
        user_prompt="Generate comprehensive test cases for this code:\n\n$code_content"
        
        echo "Generating tests for $file..."
        echo "============================="
        call_openai_api "You are an expert test engineer. Generate comprehensive test cases." "$user_prompt"
        ;;
    
    *)
        show_help
        ;;
esac

Best Practices and Optimization

Prompt Engineering for Code Generation

python

# Best practices for code generation prompts

# Specific and detailed prompts
good_prompt = """
Create a Python class for a database connection pool that:
- Supports PostgreSQL and MySQL
- Implements connection pooling with configurable min/max connections
- Handles connection timeouts and retries
- Includes health checks for connections
- Provides async/await support
- Implements proper resource cleanup
- Includes comprehensive logging
- Follows the context manager protocol
"""

# Include constraints and requirements
constrained_prompt = """
Implement a rate limiter in Go that:
- Uses the token bucket algorithm
- Supports distributed rate limiting with Redis
- Handles burst traffic up to 1000 requests/second
- Includes metrics collection
- Must be thread-safe
- Should have minimal memory footprint
- Include benchmark tests
- Follow Go best practices and idioms
"""

# Request specific output format
formatted_prompt = """
Generate a React TypeScript component with the following structure:

1. Interface definitions for props and state
2. Component implementation with hooks
3. CSS module styles
4. Unit tests with React Testing Library
5. Storybook stories for documentation

Component requirements:
- Data table with sorting and filtering
- Pagination support
- Accessibility compliance (ARIA labels)
- Responsive design
- Error boundary handling
"""

Code Quality Validation

python

#!/usr/bin/env python3
# code-quality-validator.py

import ast
import subprocess
import tempfile
import os
from typing import List, Dict

class CodeQualityValidator:
    def __init__(self):
        self.quality_checks = {
            "python": self.validate_python_code,
            "javascript": self.validate_javascript_code,
            "typescript": self.validate_typescript_code
        }
    
    def validate_generated_code(self, code: str, language: str) -> Dict:
        """Validate generated code quality"""
        
        validator = self.quality_checks.get(language)
        if not validator:
            return {"error": f"No validator for language: {language}"}
        
        return validator(code)
    
    def validate_python_code(self, code: str) -> Dict:
        """Validate Python code quality"""
        
        issues = []
        
        # Syntax check
        try:
            ast.parse(code)
        except SyntaxError as e:
            issues.append(f"Syntax error: {e}")
            return {"valid": False, "issues": issues}
        
        # Create temporary file for linting
        with tempfile.NamedTemporaryFile(mode='w', suffix='.py', delete=False) as f:
            f.write(code)
            temp_file = f.name
        
        try:
            # Run flake8 for style checking
            result = subprocess.run(
                ['flake8', '--max-line-length=88', temp_file],
                capture_output=True,
                text=True
            )
            
            if result.returncode != 0:
                issues.extend(result.stdout.split('\n'))
            
            # Run bandit for security checking
            result = subprocess.run(
                ['bandit', '-f', 'txt', temp_file],
                capture_output=True,
                text=True
            )
            
            if result.returncode != 0 and "No issues identified" not in result.stdout:
                issues.append(f"Security issues found: {result.stdout}")
            
            # Check for best practices
            if 'import *' in code:
                issues.append("Avoid wildcard imports")
            
            if 'except:' in code and 'except Exception:' not in code:
                issues.append("Use specific exception handling")
            
            # Check for documentation
            if 'def ' in code and '"""' not in code:
                issues.append("Missing docstrings for functions")
        
        finally:
            os.unlink(temp_file)
        
        return {
            "valid": len(issues) == 0,
            "issues": [issue for issue in issues if issue.strip()],
            "language": "python"
        }
    
    def validate_javascript_code(self, code: str) -> Dict:
        """Validate JavaScript code quality"""
        
        issues = []
        
        # Create temporary file
        with tempfile.NamedTemporaryFile(mode='w', suffix='.js', delete=False) as f:
            f.write(code)
            temp_file = f.name
        
        try:
            # Run ESLint if available
            result = subprocess.run(
                ['eslint', '--format', 'compact', temp_file],
                capture_output=True,
                text=True
            )
            
            if result.returncode != 0:
                issues.extend(result.stdout.split('\n'))
            
            # Basic checks
            if 'eval(' in code:
                issues.append("Avoid using eval() - security risk")
            
            if 'var ' in code:
                issues.append("Use 'let' or 'const' instead of 'var'")
        
        except FileNotFoundError:
            issues.append("ESLint not available - install for better validation")
        
        finally:
            os.unlink(temp_file)
        
        return {
            "valid": len(issues) == 0,
            "issues": [issue for issue in issues if issue.strip()],
            "language": "javascript"
        }
    
    def validate_typescript_code(self, code: str) -> Dict:
        """Validate TypeScript code quality"""
        
        issues = []
        
        # Create temporary file
        with tempfile.NamedTemporaryFile(mode='w', suffix='.ts', delete=False) as f:
            f.write(code)
            temp_file = f.name
        
        try:
            # Run TypeScript compiler
            result = subprocess.run(
                ['tsc', '--noEmit', '--strict', temp_file],
                capture_output=True,
                text=True
            )
            
            if result.returncode != 0:
                issues.extend(result.stderr.split('\n'))
            
            # Check for TypeScript best practices
            if ': any' in code:
                issues.append("Avoid using 'any' type - use specific types")
            
            if '// @ts-ignore' in code:
                issues.append("Avoid @ts-ignore - fix type issues instead")
        
        except FileNotFoundError:
            issues.append("TypeScript compiler not available")
        
        finally:
            os.unlink(temp_file)
        
        return {
            "valid": len(issues) == 0,
            "issues": [issue for issue in issues if issue.strip()],
            "language": "typescript"
        }

def main():
    validator = CodeQualityValidator()
    
    # Example Python code validation
    python_code = '''
def calculate_factorial(n):
    """Calculate factorial of a number."""
    if n < 0:
        raise ValueError("Factorial not defined for negative numbers")
    if n == 0 or n == 1:
        return 1
    return n * calculate_factorial(n - 1)
'''
    
    result = validator.validate_generated_code(python_code, "python")
    print("Python Code Validation:")
    print(f"Valid: {result['valid']}")
    if result['issues']:
        print("Issues:")
        for issue in result['issues']:
            print(f"  - {issue}")

if __name__ == "__main__":
    main()

Troubleshooting and Common Issues

API Migration Issues

python

# Common migration issues from Codex to GPT models

# Issue 1: Different response format
# Old Codex format
# response.choices[0].text

# New GPT format
# response.choices[0].message.content

# Issue 2: Different prompt structure
# Old Codex (completion)
prompt = "# Function to calculate factorial\ndef factorial(n):"

# New GPT (chat)
messages = [
    {"role": "system", "content": "You are an expert Python developer."},
    {"role": "user", "content": "Write a function to calculate factorial"}
]

# Issue 3: Stop sequences
# Old Codex
# stop=["#", "\n\n"]

# New GPT (handled differently)
# Use system prompts to control output format

Performance Optimization

python

# Optimize API usage for better performance

class OptimizedCodeGenerator:
    def __init__(self):
        self.cache = {}
        self.batch_requests = []
    
    def cached_generation(self, prompt: str, language: str) -> str:
        """Use caching to avoid duplicate requests"""
        
        cache_key = f"{language}:{hash(prompt)}"
        
        if cache_key in self.cache:
            return self.cache[cache_key]
        
        # Generate code
        result = self.generate_code(prompt, language)
        
        # Cache result
        self.cache[cache_key] = result
        
        return result
    
    def batch_generation(self, prompts: List[str], language: str) -> List[str]:
        """Batch multiple requests for efficiency"""
        
        # Combine prompts
        combined_prompt = "Generate code for the following requests:\n\n"
        
        for i, prompt in enumerate(prompts, 1):
            combined_prompt += f"{i}. {prompt}\n\n"
        
        combined_prompt += f"Provide {language} code for each request, numbered accordingly."
        
        # Single API call
        response = self.generate_code(combined_prompt, language)
        
        # Parse responses (simplified)
        responses = response.split(f"{i+1}.")
        
        return responses[:len(prompts)]

Resources and Documentation

Official Resources

Migration Guides

Community Resources

Tools and Extensions

This cheat sheet provides comprehensive guidance for using modern AI code generation tools as replacements for the deprecated OpenAI Codex. Always validate and test AI-generated code before production use, and follow security best practices for API key management.

OpenAI Codex Code Generation Cheat Sheet ​

Overview ​

Migration to Current Models ​

GPT-3.5/GPT-4 for Code Generation ​

Legacy Codex API Usage (Historical Reference) ​

Modern Code Generation Setup ​

Python SDK Configuration ​

Example usage ​

JavaScript/TypeScript Development ​

Go Development ​

Advanced Code Generation Techniques ​

Context-Aware Generation ​

Save results ​

Vim/Neovim Plugin ​

Emacs Integration ​

Command Line Tools ​

CLI Code Generator ​

Best Practices and Optimization ​

Prompt Engineering for Code Generation ​

Code Quality Validation ​

Troubleshooting and Common Issues ​

API Migration Issues ​

Performance Optimization ​

Resources and Documentation ​

Official Resources ​

Migration Guides ​

Community Resources ​

Tools and Extensions ​

OpenAI Codex Code Generation Cheat Sheet

Overview

Migration to Current Models

GPT-3.5/GPT-4 for Code Generation

Legacy Codex API Usage (Historical Reference)

Modern Code Generation Setup

Python SDK Configuration

Example usage

JavaScript/TypeScript Development

Go Development

Advanced Code Generation Techniques

Context-Aware Generation

Save results

Vim/Neovim Plugin

Emacs Integration

Command Line Tools

CLI Code Generator

Best Practices and Optimization

Prompt Engineering for Code Generation

Code Quality Validation

Troubleshooting and Common Issues

API Migration Issues

Performance Optimization

Resources and Documentation

Official Resources

Migration Guides

Community Resources

Tools and Extensions