# Create Your First Extension

## Create a new extension

Open the Create Extension command, name your extension "Hello World" and select the "Detail" template. Pick a parent folder in the Location field and press `⌘` `↵` to continue.

![Create Extension command in Raycast](https://2922539984-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Me_8A39tFhZg3UaVoSN%2Fuploads%2Fgit-blob-3cf0d0478508eca468e31c4f9ee871ea269d71e4%2Fhello-world.webp?alt=media)

{% hint style="info" %}
To create a private extension, select your organization in the first dropdown. You need to be logged in and part of an organization to see the dropdown. Learn more about Raycast for Teams [here](https://developers.raycast.com/teams/getting-started).
{% endhint %}

{% hint style="info" %}
To kickstart your extensions, Raycast provides various templates for commands and tools. Learn more [here](https://developers.raycast.com/information/developer-tools/templates).
{% endhint %}

Next, you'll need to follow the on-screen instructions to build the extension.

## Build the extension

Open your terminal, navigate to your extension directory and run `npm install && npm run dev`. Open Raycast, and you'll notice your extension at the top of the root search. Press `↵` to open it.

![Your first extension](https://2922539984-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Me_8A39tFhZg3UaVoSN%2Fuploads%2Fgit-blob-2927c54a56a87fd95fb0340b9acfcd26f48f0f40%2Fhello-world-2.webp?alt=media)

## Develop your extension

To make changes to your extension, open the `./src/index.tsx` file in your extension directory, change the `markdown` text and save it. Then, open your command in Raycast again and see your changes.

{% hint style="info" %}
`npm run dev` starts the extension in development mode with hot reloading, error reporting and [more](https://developers.raycast.com/information/developer-tools/cli#development).
{% endhint %}

## Use your extension

Now, you can press `⌃` `C` in your terminal to stop `npm run dev`. The extension stays in Raycast, and you can find its commands in the root when searching for the extension name "Hello World" or the command name "Render Markdown".

![Find your extension in the root search](https://2922539984-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Me_8A39tFhZg3UaVoSN%2Fuploads%2Fgit-blob-2927c54a56a87fd95fb0340b9acfcd26f48f0f40%2Fhello-world-2.webp?alt=media)

🎉 Congratulations! You built your first extension. Off to many more.

{% hint style="info" %}
Don't forget to run [`npm run dev`](https://developers.raycast.com/information/developer-tools/cli#development) again when you want to change something in your extension.
{% endhint %}