# Your first change

> Walk your agent through one safe change to your site, from reading a file to seeing it on the draft preview and publishing it.

Last updated: October 16, 2026

Source: https://www.willo.ai/docs/ai-agents/your-first-change

This walks through one small site change made by your agent: read a file, edit it, check it on the draft preview, then publish. It needs a read + act token. If you only have a read-only token, [create another](https://www.willo.ai/docs/ai-agents/connect-your-agent#1-create-a-token).

## Before you start: is the business drafting?

Ask the agent to call `willo_status`. It says whether a draft is open.

- **Drafting on.** Changes land on the `draft` branch and the draft preview. Nothing reaches the live site until someone publishes.
- **Drafting off.** Changes go to the live site at once, and the site rebuilds within a few minutes.

Drafting is a per-business setting, and turning it on needs a paid plan. For a first change, drafting on is the comfortable choice. [Draft and live](https://www.willo.ai/docs/ai-agents/draft-and-live) explains both modes.

## 1. Read the file

Prompt: "Read the home page file and show me the hero headline."

The agent calls `willo_list_files` to find the file, then `willo_read_file` with its path, for example `src/pages/index.astro`. The result includes the file's lines and its `sha`, a fingerprint of that exact version.

## 2. Make the edit

Prompt: "Change the hero headline to 'Fresh bread, baked at dawn.'"

The agent calls `willo_edit_file` with the exact text to replace and the new text, plus a one-sentence `summary` for you. An edit replaces text only where it matches exactly once, so it cannot land in the wrong place. To replace a whole file the agent uses `willo_write_file`, which needs the `sha` from step 1: if anyone changed the file since the agent read it, the write is refused instead of overwriting their work.

Most file changes run straight away, as they do in Willo's chat. Two kinds stop for your approval: deleting a file, and changing `package.json` or a lockfile, because a dependency change can break the build. See [Approvals](https://www.willo.ai/docs/ai-agents/approvals).

## 3. See it on the draft preview

Open the business's **Build** page. The draft preview rebuilds on every saved change, which takes a couple of minutes. To list everything the draft changes compared with the live site, ask the agent to call `willo_diff`.

Every change your agent makes to site files shows in the dashboard's **Activity** tab with an **Undo**.

## 4. Publish

When the draft looks right, publish it. Either:

- click **Publish** on the Site page yourself, or
- ask the agent to call `willo_publish`. It always needs your approval: the agent gets a link to a card, you approve it on the dashboard, and the agent calls `willo_publish` again to start the publish.

Publishing ships every unpublished change, from you, from Willo's chat and from the agent, together. It takes a few minutes, and `willo_status` shows when it is live. There is no one-click undo for a publish, so check the preview first.

## If a live deploy fails

When drafting is off, or after a publish, the live site rebuilds. If that build fails because of the agent's change, Willo does not start its own automatic fix. The agent is expected to fix it: `willo_status` shows the build error, and the agent corrects the file and writes again. You can also ask Willo's chat to fix it.

## What to try next

- [Approvals](https://www.willo.ai/docs/ai-agents/approvals): what stops for you, and how the agent waits.
- [Deploy an edge function from your agent](https://www.willo.ai/docs/ai-agents/deploy-an-edge-function).
- [Change the database schema from your agent](https://www.willo.ai/docs/ai-agents/change-the-database-schema).