Background

As part of the WIkipedia 25 celebrations, we're seeking to build an extension that will optionally give users a fun mascot during their reading experience.

This experience is going to launch for a limited duration and specifically only on various language WIkipedias that have opted into this experience. Individual users will also be required to opt-in to this experience.

For community collaboration process is documented in detail on the following page on meta-wiki
https://meta.wikimedia.org/wiki/Wikipedia_25/Easter_egg_experiments

Audience scope

We want this experience to be available to users on Wikipedia under the following circumstances:

• Users who are browsing a specific language wiki that has opted into this experience
• Users who are either logged-in or logged-out can opt-in to this experience
• This user preference is persisted while users browse the wiki.

Technical support requirements

We aim for our environment's modern browser support with graceful degradation.
We might revisit and expand the support after successful launch of the extension in the remaining short timeline.

Workflows

Per-wiki opt-in

1. The extension is deployed in production, but disabled by default
2. The extension provides a community config interface to enable wiki admins to enable this feature on certain pages
3. Wiki admins enable the extension on their specific wiki with various options.

Per-user opt-in

1. Once the extension has been enabled on a wiki, the user will receive an option to enable "Birthday mode" via specific options in the interface (on both Vector 2022 skin and MinervaNeue skin)
2. When someone enables the "birthday mode" then a light-hearted mascot will appear on the screen and occasionally animate during their reading experience.
3. If a user wishes to opt-out of the experience, they can click the option to disable this experience.

Designs

Technical Integration

1. Wikibase
2. Community Configuration
3. Client preferences (skin based)