---
slug: how-to-choose-engine-and-model
title: Choose the engine and model for a task
category: capability
status: published
tags: [engine, model, harness, runtime, claude code, codex, hermes, bring your own, byo cli, switch engine, switch model, which model, new task, 引擎, 模型, 换引擎, 换模型, 选模型, 选引擎]
aliases: []
lastEditAt: 2026-08-11
---
Tycoon can run a task on any engine and any model — the choice is yours, and it now sits right on the **New task** panel instead of behind a collapsed menu.

**Where do I see it?**

Open **New task**, write your request, and pick who should do it. As soon as you choose a runner that can run on more than one engine — a developer agent, a custom agent, or one you hired — two controls appear in the composer: an **Engine** pill and a **Model** pill. They are always visible; there is nothing to expand.

**What can I pick?**

- **Engine** — nine runtimes: the built-in **Claude Code**, **Codex**, and **Hermes**, plus six *Bring your own* CLIs you have paired. Leaving it on **Auto / Default** lets Tycoon Agent pick the best one.
- **Model** — the full catalog, selectable across engines. Choosing a model that needs a different engine switches the engine for you; otherwise the Model follows the engine's default until you change it.

Tycoon Agent (the manager) runs on a fixed internal engine, so these controls stay hidden until you assign the task to another agent.

**What does it cost?**

Usage is billed to your workspace wallet at actual metered cost. Heavier models cost more per token, so **Auto** is usually the economical default — switch up only when a task truly needs it.