# Exercise 02: Control the Loop

**Concept:** The Agent Loop (CC-001)
**Level:** Intermediate
**Time:** ~15 minutes

---

## Objective

Learn to steer the agent loop instead of just watching it. You will
use Plan Mode to preview what Claude intends to do before it acts,
and use /rewind to undo a wrong turn.

Exercise 01 showed the loop running freely. This exercise shows you
the controls.

---

## Before You Start

Confirm you have:

- [ ] Completed Exercise 01 (or understand the basic loop concept)
- [ ] Claude Code open in this directory

---

## Part A: Plan Mode

**Step 1:** Press `Shift+Tab` until the mode indicator shows **plan**.

You should see the permission mode change in the bottom bar. In Plan
Mode, Claude will describe what it plans to do instead of doing it.

**Step 2:** Paste this prompt:

```
Create a project structure for a simple blog:
- A folder called blog/ with index.html, style.css, and posts/
- An about.html page
- A README.md explaining the structure
```

**Step 3:** Read Claude's plan.

Claude will describe the files it would create, the structure, and
the content. It will NOT create anything yet. This is the plan.

**Step 4:** If the plan looks good, type:

```
Go ahead, execute this plan.
```

Or press `Shift+Tab` back to a normal mode and re-send the prompt.

Claude now executes, creating the actual files.

**Why this matters:** For complex tasks where a wrong start wastes
time, Plan Mode lets you course-correct before any files are written.

---

## Part B: Using /rewind

**Step 1:** Give Claude an intentionally vague prompt:

```
Improve the blog project.
```

Claude will likely make some changes you did not expect or want.
That is the point of this exercise.

**Step 2:** After Claude finishes, review what it changed. If the
changes are not what you wanted, type:

```
/rewind
```

This restores your context to the state before Claude's last action.
The files are unchanged (Claude did write them), but the conversation
context is rewound so you can try a different approach.

**Step 3:** Now give a more specific prompt:

```
Add a navigation bar to index.html that links to about.html.
Do not change anything else.
```

Notice how specificity gives the loop better direction.

---

## Part C: Stopping a Runaway Loop

**Step 1:** Give Claude a deliberately open-ended task:

```
Make this blog production-ready.
```

**Step 2:** As Claude starts working (adding frameworks, build tools,
etc.), press `Escape` to interrupt.

Claude stops mid-execution. You can then redirect:

```
Stop. I just want the HTML and CSS to be clean and valid.
No frameworks, no build tools.
```

---

## Expected Output

After completing all three parts:

- A `blog/` directory with `index.html`, `style.css`, `posts/`, `about.html`, `README.md`
- You experienced Plan Mode (preview before execution)
- You used /rewind to undo a vague prompt
- You interrupted a runaway loop with Escape

---

## What You Learned

- **Plan Mode previews:** Shift+Tab toggles Plan Mode, where Claude describes its plan before acting
- **/rewind undoes context:** It rolls back the conversation so you can try a different approach
- **Escape interrupts:** Press Escape to stop Claude mid-loop when it is going in the wrong direction
- **Specificity guides the loop:** Vague prompts produce unpredictable results. Specific prompts keep the loop on track.

---

## Clean Up

```bash
rm -rf blog/ about.html
```

---

## Next

Ready to design prompts that work with the loop? Move to [Exercise 03: Design for the Loop](./03-design-for-the-loop.md).