---
title: Model Selection
description: Folded into Recipes.
---

This material is now in [Recipes](/recipes).

Smithers defaults to Codex whenever usable Codex authentication is available:

| Work | Model |
|---|---|
| Planning, orchestration, review, and the hardest reasoning | `gpt-5.6-sol` |
| Mid-tier judgment, validation, or tool-heavy work that needs extra checking | `gpt-5.6-terra` |
| **Research, implementation, ordinary tool use, UI, and routine-to-substantial execution** | `gpt-5.6-luna` |

Pin the exact tier IDs above instead of the floating `gpt-5.6` alias. Start
with Luna for most work, including substantial implementation and ordinary
tool use; task size alone does not require Sol. Escalate to Terra for stronger
validation or structured tool-heavy judgment, and to Sol for ambiguity,
high-stakes decisions, novel architecture, orchestration, final review, or
repeated failure. See [SOTA role defaults](/reference/sota-models#role-defaults).

When Codex is unavailable, Smithers falls back to detected Claude, Kimi,
Gemini, or other compatible adapters. Explicit provider-specific workflows
remain supported. The [SOTA model registry](/reference/sota-models) lists the
current defaults and badges and is refreshed by a daily research job.
