Video by OpenAI via YouTube

Get more useful work from every token with GPT‑5.6. In this Build Hour, you’ll learn how to choose the right model for your workload—and migrate production agents while improving speed, cost, and performance.
Charlie Guo (DevEx), Bryant Chou (Founder, Ploy) and Lorenzo Gentile (AI Engineer, Ploy) will cover how to:
• Choose between GPT‑5.6 Sol, Terra, and Luna based on intelligence, latency, and cost
• Measure and optimize cost-performance across real workloads
• Adapt evals, agent harnesses, tool schemas, and prompt caching when migrating models
• Move production agents to GPT‑5.6, featuring a customer spotlight on how Ploy achieved 2.2× faster builds at 27% lower cost
• Apply these lessons through live demos and Q&A
👉 GPT-5.6 blog: https://openai.com/index//gpt-5-6
👉 Programmatic tool-calling: https://developers.openai.com/api/docs/guides/tools-programmatic-tool-calling
👉 Compare models: https://developers.openai.com/api/docs/models/compare
👉 Migrating a production AI agent: https://ploy.ai/blog/migrating-a-production-ai-agent-to-gpt-5-6
👉 Build Hour repo: https://github.com/openai/build-hours
00:00 Introduction
02:50 Tokenmaxxing vs. valuemaxxing
07:11 Valuemaxxing Codex
15:16 Valuemaxxing your harness
23:48 Customer spotlight: Ploy’s migration to GPT-5.6
39:57 Q&A
53:13 Resources and closing