ChatGPT Custom GPTs 2026 — How to Build and Use Your Own AI Complete Guide Custom GPTs let anyone build specialized AI assistants without coding. This complete guide covers how to create, configure, and use Custom GPTs — including the GPT Store, best-use configurations, API actions, and the top Custom GPTs available in 2026. What Are Custom GPTs? Custom GPTs are user-configurable AI assistants built on the ChatGPT/GPT-4o foundation, specialized for specific tasks, topics, or