# Agents and models

Each task picks an **agent**, the coding tool that does the work, and a
**model**, which drives it. The agent stays the same for the whole
conversation; the model and reasoning level can change on every turn.

## Agents

| Agent | Steer a running turn | Asks you questions | Subagents | Strongest reasoning |
|---|---|---|---|---|
| Claude Code | Yes | Yes, and plan approvals | Yes | max |
| Codex | Yes | Yes | Yes | max |
| OpenCode | — | Yes | Yes | max |
| Kilo Code | — | Yes | Yes | max |
| pi | — | — | — | high |

Every agent runs as its own command-line tool, with its own session, inside the
conversation's sandbox, and every agent shows its work in the same **Chat** and
**Trajectory** views. All five can use your [MCP servers](tools.md#mcp-servers),
[skills](tools.md#skills) and [plugins](tools.md#plugins).

- **Steer a running turn:** a message sent with **Steer now** reaches the agent
  before its next tool call. With the other agents, a message sent during a
  turn waits for the next one. See [Follow-ups](tasks.md#follow-ups).
- **Subagents:** when an agent delegates work, the **Tasks and subagents**
  window shows each subagent's assignment, model and reply, and you can open
  the subagent's own conversation and steps. See
  [Tasks and subagents](navigation.md#tasks-and-subagents).

## Models

The composer lists the models enabled for agent tasks on your account, which
during the beta can be a subset of the full [model catalog](../models.md). A
new task starts on the default model. The control beside the message box
starts each follow-up on the model the previous turn used.

## Reasoning

Where the agent and model support it, the **Reasoning** control sets how much
the model thinks before acting. The levels each agent offers differ; higher
levels are slower and use more of your quota.

## Choosing

| Work | A good starting point |
|---|---|
| Mechanical sweeps, renames, small fixes | A fast model, low or medium reasoning |
| A bug with a clear reproduction, a focused feature | The default model, high reasoning |
| Open-ended design, hard debugging | A larger model, the strongest reasoning |

If you already use one of these agents locally, pick the same one here: it
reads the same `AGENTS.md` or `CLAUDE.md` and behaves the way you know.