OpenAI

Core Products & Tools

• ChatGPT
• Prompt Optimizer
• OpenAI Playground
• GPT Store
• Create a GPT Requires at least Plus account

Documentation & Guides

• OpenAI Models

• OpenAI Prompt Engineering Docs

• OpenAI Reasoning Models Docs
• OpenAI Cookbook
• OpenAI gpt-5 prompting guide
• OpenAI Function calling
• OpenAI GPTs Documentation
• OpenAI API Reference
• OpenAI Guide to building agents

Legacy Docs

• How to choose models Prior to GPT-5
• OpenAI gpt4.1 prompting guide

Development & Testing

• OpenAI Evals
• OpenAI Tokenizer
• OpenAI Model Spec

Community & Updates

• OpenAI Blog
• OpenAI Developer Forum
• OpenAI Academy

Coding Tools

• Codex
• OpenAI Agents SDK lightweight python framework for building multi-agent workflows