> ## Documentation Index
> Fetch the complete documentation index at: https://docs.trysixth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Plan, Act & Explore

> Sixth's three modes: plan the work, build it, or investigate and document a codebase.

Sixth has three modes. Pick one with the mode button in the bottom-left of the message box, or press `⌘/Ctrl + Shift + A` to cycle **Act → Plan → Explore**.

| Mode | What it's for | Changes your files? |
| - | - | - |
| **Act** | Build and execute immediately | Yes |
| **Plan** | Gather information and architect a plan with you | No |
| **Explore** | Deep codebase investigation and documentation | Only its own report file |

You can switch modes in the middle of a task. Sixth keeps the full conversation, so a plan you made in Plan mode carries straight into Act mode.

## Act mode

Act is the default. Sixth has its full toolset: it reads and edits files, runs commands, uses the browser, calls MCP tools and integrations, spawns [sub-agents](/features/sub-agents) and generates images, asking for approval wherever you haven't [auto-approved](/features/auto-approve).

Use Act for routine changes, for implementing a plan you've already agreed, and for running tests and fixing what they find.

## Plan mode

In Plan mode Sixth reads your codebase, asks questions and works out an approach with you, but doesn't change anything. Its replies can include options you can pick from with a click or a number key.

Use Plan mode when:

* the approach isn't obvious yet,
* you're debugging something and aren't sure of the cause,
* a change affects several parts of the codebase.

When the plan looks right, switch to Act and tell Sixth to go ahead.

<Tip>Turn on **Enable strict plan mode** in **Settings → Features** to hard-block file edits while in Plan mode.</Tip>

For larger plans you can also:

* Use [`/deep-planning`](/features/slash-commands/deep-planning) to have Sixth investigate thoroughly before writing an implementation plan.
* Use [`/interactive-planning`](/features/interactive-planning) to see the plan as an interactive flowchart you can edit and approve.

## Explore mode

Explore mode turns Sixth into a codebase analyst. It reads the project, works out how it's structured and how the pieces fit together, and writes up what a developer needs to know to work in it.

* Every Explore session saves its report to a file in your project root: `project_info__1.md`, then `project_info__2.md`, and so on. It also shows the report in the chat.
* Explore can't run commands that change anything or edit your code. If you ask it to build something, it'll point you to Act mode.

Explore is ideal when you're new to a codebase, picking up an unfamiliar repo, or onboarding a teammate.

## A typical flow

1. **Explore** an unfamiliar repo to get the lay of the land.
2. **Plan** the feature: share requirements, let Sixth read the relevant files, settle the approach.
3. **Act** to implement it, with [checkpoints](/features/checkpoints) after every change.
4. Drop back into **Plan** whenever you hit something unexpected.


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