The agent

The agent is what makes Clusy more than a notebook. It's the AI you talk to in chat, and it can do most of what you can do in the notebook: write cells, run them, read the results, inspect what's in memory, search the web, and decide what to do next.

It works in a loop

For anything non-trivial, the agent doesn't write one block of code and stop. It plans a few steps, writes a cell, runs it, looks at the output, and decides what's next. If a cell errors, it reads the traceback and tries a fix. You watch this happen: the plan shows as a card, cells appear and run, and the agent tells you what it found before moving on.

What shows up in chat

The agent's work comes through as cards, not just paragraphs:

• Plan: the steps it's about to take. Reply to redirect it before it starts.
• Thinking: a collapsible block of reasoning, on the models that support it.
• Suggestion: a proposed cell or edit, with Accept, Edit, and Skip.
• Tool call: a compact row for something it ran. Expand it to see the details.
• Clarification: a question it needs answered to keep going.
• Research: results it pulled from the web, with sources.
• Sub-agent: a worker it spawned for a chunk of the job (more on this below).

When it asks you

The agent is built to keep going on the mechanical parts and stop on the judgment calls: which column to predict, whether dropping rows with nulls is fine, which of two approaches you'd rather take. Those come through as a clarification, or sometimes as a control cell right in the notebook. When it's only proposing something, you get a suggestion or a ghost cell you can accept or skip. You're the one who commits the change.

You don't have to wait for it to finish, either. Send another message and it re-plans. Edit a cell yourself and it picks up from your version.

Sub-agents

For work that's large or splits into parts, the agent can spawn sub-agents: focused workers that each take a piece and report back. A research task might fan out into several searches. You can open a worker's trace from the chat to see its full reasoning and output, so the work stays inspectable.

It remembers your reactions

When you accept, edit, or skip a suggestion, that's recorded. Over time it shapes what the agent offers you, so it tends to fit your habits better the more you use it.

Plan mode

For a big job, you can have the agent research and lay out a full plan before it writes any code, then approve it and watch it build and run. Flip on the Plan toggle in the chat composer to switch into Plan mode.

Which model is behind it

"The agent" isn't one fixed model. You choose which model backs it, from a fast free default up to the most capable ones, and the choice changes how it behaves. See Choosing a model.