A full-blown guide to building complete software projects using OpenAI's Codexβstep by step. From setting up the API to generating, testing, and deploying code using Codex (via Playground, API, or GitHub Copilot).
OpenAI Codex is a large language model by OpenAI, specialized in code generation. It powers:
- GitHub Copilot
- OpenAI Playground (code modes)
- ChatGPT (coding features)
It understands natural language and translates it into actual working code.
- Sign up: https://platform.openai.com/signup
- Go to: https://platform.openai.com/account/api-keys
- Generate your API key to use with REST or SDK.
Visit OpenAI Playground:
- Choose
code-davinci-002orgpt-4o - Prompt:
"Write a Python function to generate a Fibonacci sequence."
pip install openaiimport openai
openai.api_key = "your-api-key"
response = openai.Completion.create(
engine="code-davinci-002",
prompt="Write a JavaScript function to validate an email address.",
temperature=0,
max_tokens=100,
stop=["#"]
)
print(response.choices[0].text.strip())Write a clear prompt like:
Build a Flask API with two endpoints: one for file upload, one for listing files.
Break it into subtasks:
- Create route handlers
- Add file logic
- Implement auth
- Add validation
- Add logging & error handling
Create a Flask endpoint /upload that saves a file to /uploads.
from flask import Flask, request
import os
app = Flask(__name__)
UPLOAD_FOLDER = 'uploads'
os.makedirs(UPLOAD_FOLDER, exist_ok=True)
@app.route('/upload', methods=['POST'])
def upload_file():
file = request.files['file']
if file:
filepath = os.path.join(UPLOAD_FOLDER, file.filename)
file.save(filepath)
return {'message': 'File uploaded successfully'}, 200
return {'error': 'No file provided'}, 400
if __name__ == '__main__':
app.run(debug=True)Prompt:
Write pytest cases for this Flask file upload API.
Example output:
def test_upload_file(client):
data = {'file': (BytesIO(b'content'), 'test.txt')}
response = client.post('/upload', data=data, content_type='multipart/form-data')
assert response.status_code == 200Prompt:
Generate a README.md for this Flask file upload API.
Codex can produce:
- Project setup
- Usage instructions
- API endpoints
- Example curl commands
Steps:
- Install GitHub Copilot extension in VSCode
- Sign in via GitHub
- Start coding and watch auto-suggestions
- Use comments to guide Copilot:
# Function to convert CSV to JSON
Prompt:
Create a To-Do list web app using HTML/CSS/JS with:
- Add item
- Delete item
- Mark complete
- Save to localStorage
Result: Full HTML + JS ready to deploy!
- β Use clear, focused prompts
- π Iterate for refinement
- π§ͺ Always test before using in production
- π¬ Use comments and examples in your prompts
- π Donβt paste sensitive data or credentials
Use Codex To Build Software:
β
βββ 1. Get OpenAI Access
βββ 2. Test via Playground
βββ 3. Write Prompt-Based Code
βββ 4. Break Down Requirements
βββ 5. Generate Code Snippets
βββ 6. Create Docs & Tests
βββ 7. Use GitHub Copilot
βββ 8. Build Apps Interactively
βββ 9. Review, Secure, Deploy
βββ 10. Repeat & Refactor!
- OpenAI Docs: https://platform.openai.com/docs
- GitHub Copilot: https://github.com/features/copilot
- Explore Codex Models:
code-davinci-002,gpt-4o
Drop a β on this Gist if it helped.
Follow me on GitHub π Sharique55
has anyone jail broke chat-gpt from the terminal using codex? i reckon it would rip systems with agent built malware. nice write up Sharique55