How to Use the OpenAI API: A Beginner's Complete Tutorial (2026)

Summary: You can make your first AI API call in under 5 minutes. This guide walks you through getting an API key, installing the SDK, making your first request, and building a simple chatbot — with real tested code examples that work today. Prerequisites Python 3.8+ installed A terminal or code editor An API key (we'll get one below) That's it. No machine learning knowledge required. Step 1: Get Your API Key (2 minutes) You have two options: Option A: Direct from OpenAI Go to platform.openai.com Sign up or log in Navigate to API Keys → Create new secret key Copy the key (starts with sk- ) Add payment method (pay-per-use, starts at $5) Option B: Through an API Gateway (recommended for beginners) An API gateway gives you one key that works with all AI models (GPT-5, Claude, Gemini, DeepSeek), not just OpenAI. It's also significantly cheaper. Go to crazyrouter.com Register (free, includes $0.20 starter credit) Copy your API key from the dashboard Use base_url="https://crazyrouter.com/v1"