#
Static HTML Spaces

Spaces also accommodate custom HTML for your app instead of using Streamlit or Gradio. Set `sdk: static` inside the `YAML` block at the top of your Spaces README.md file. Then you can place your HTML code within an index.html file.

Here are some examples of Spaces using custom HTML:

- Smarter NPC: Display a PlayCanvas project with an iframe in Spaces.
- Huggingfab: Display a Sketchfab model in Spaces.
- Diffuse the rest: Draw and diffuse the rest

##
Adding a build step before serving

Static Spaces support adding a custom build step before serving your static assets. This is useful for frontend frameworks like React, Svelte and Vue that require a build process before serving the application. The build command runs automatically when your Space is updated.

Add `app_build_command` inside the `YAML` block at the top of your Spaces README.md file, and `app_file`.

For example:

- `app_build_command: npm run build`
- `app_file: dist/index.html`

Example spaces:

- Svelte App
- React App

Under the hood, it will launch a build, storing the generated files in a special `refs/convert/build` ref.

##
Space variables

Custom environment variables can be passed to your Space. OAuth information such as the client ID and scope are also available as environment variables, if you have enabled OAuth for your Space.

To use these variables in JavaScript, you can use the `window.huggingface.variables` object. For example, to access the `OAUTH_CLIENT_ID` variable, you can use `window.huggingface.variables.OAUTH_CLIENT_ID`.

Here is an example of a Space using custom environment variables and oauth enabled and displaying the variables in the HTML:

- Static Variables

Update on GitHub