AI Model Updates: Opus 5.5, GPT 6 Sol/Luna, Fireworks retirements & default

The Agent Builder now offers an expanded set of models:

• New models you can select: Claude Opus 5.5 (including a Thinking variant), GPT-6 Sol, and GPT-6 Luna.
• Every new agent now starts on NinjaCat (US) by default — an easy way to use a model NinjaCat recommends as a strong choice across many kinds of tasks, without having to pick one yourself. You can switch any agent to a different model at any time.
• Existing agents keep their current model — nothing changes unless you change it.
• Some older models are being retired. Agents already using a retired model keep working and are automatically routed to a current equivalent, so no action is required. Retired models are labeled in the picker and can no longer be selected for new agents.