Route GPT-5.6 Codex Tasks with OpenAI's AMA Notes

What it is

A practical reference for choosing GPT-5.6 models in Codex after OpenAI's July 10 AMA. The useful signal is workflow guidance, not another launch recap: Sol Medium for most coding, Sol Ultra for migrations and security-sensitive work, Terra for faster or usage-conscious tasks, and Luna for lighter subagent work.

Why bookmark it

• The AMA gives direct operating guidance from the Codex team instead of benchmark-only positioning.
• TestingCatalog distilled the model-routing notes, Codex usage comments, desktop-app friction, and persistence tips into a scan-friendly summary.
• The notes are useful for teams setting default reasoning levels, test requirements, and escalation rules after the GPT-5.6 rollout.

Good first use

Turn the AMA notes into a small routing checklist for your coding agents: task risk, repository size, required tests, acceptable latency, and when to move from Sol Medium to higher reasoning or Sol Ultra.

Risk notes

Treat Reddit comments and social summaries as context, not product documentation. Verify model availability, usage allowances, pricing, and context-window behavior in your own ChatGPT, Codex, or API account before changing production defaults.