# Explain changes & commit messages

The commit box in Local Changes has two AI buttons, when an AI tool is connected
([Claude Code & Codex](/docs/ai/claude-code-and-codex)).

## Propose a message

The **✦** button proposes a subject and a description from the staged changes. If the box already has text, the
proposal waits for your yes before it replaces it. **Stop** cancels it while it is being written.

## Explain changes

**Explain changes** describes what the staged changes do; on a single file it reads **Explain** and that file's name.

## Large diffs

A very large diff is cut before it is sent, and tratto tells you when that happened, so you know the answer covers only
part of it.

## The prompts

The instructions sent with the diff ship with the app (`app/assets/ai/commit_assist.json`) and cannot be changed yet.
The prompt for pull request descriptions can: **Settings › Integration** opens it in an editor.