Customize the Prompt

Starlight Page Actions includes a default prompt that is automatically applied when a user opens the documentation in an AI tool like ChatGPT. This default prompt looks like this:

Read {url}. I want to ask questions about it.

You can override this behavior by providing your own custom prompt.

Why customize the prompt?

You may want to:

• Give the AI more structure or context
• Automatically set a role or behavior
• Provide instructions for how the AI should analyze your docs
• Tailor the prompt for a specific AI assistant

Customizing the prompt lets you fully control the message sent to the AI.

How to customize the prompt

Use the prompt option inside the plugin configuration:

import starlight from "@astrojs/starlight";
import { defineConfig } from "astro/config";
import starlightPageActions from "starlight-page-actions";

export default defineConfig({
  integrations: [
    starlight({
      plugins: [
        starlightPageActions({
          prompt: "Read {url} and explain its main points briefly.",
        }),
      ],
      title: "My Docs",
    }),
  ],
});

Using {url} in your prompt

You can reference the current page URL in your custom prompt by including {url}.

For example:

You are a technical assistant. Read {url} and summarize the most important concepts.

The {url} placeholder will automatically be replaced at runtime.

If you do not include {url} in your prompt, the page URL will be automatically appended at the end.