App Developer Guidelines for My Yahoo!

Using the Yahoo! Application Platform, you can build your own interactive, personalized content for My Yahoo!.

Overview of apps and the small view

Applications ("apps") for My Yahoo! are built using the Yahoo! Application Platform. Each app has two views:

The small view serves as a user's personal "dashboard" into what is going on with the app. As an example, consider a fantasy sports app. The small view is where users would get updates on trade requests, breaking information about their players, etc. The small view would have one or more links to the canvas view, where users would do most of the interaction with the application: executing trades, reviewing player statistics, and so forth. See the small view section in the YAP documentation for more information about the small view.

The small view is designed to support personalized content that is updated behind the scenes as users and their connections interact with the app. See the How to Set the Small View with the PHP SDK for more information about how to update the content of the small view.

For performance and safety reasons, the small view is based on a cached model with restricted markup (HTML + "YML lite" + CSS). See the YML documentation for details on YML and YML lite.

Design considerations for apps on My Yahoo!


  • The width of the small view of an app on My Yahoo! is constrained by the column in which the app is placed.
  • The smallest supported width is 300px, and all small views should work at that width.
  • Column widths on My Yahoo! are variable, so app small views should be coded to "flex" as the column width changes.
  • While there’s technically no maximum width, we ask developers to develop code that flexes gracefully up to about 600px.


  • The My Yahoo! layout adjusts to accommodate the full height of an app’s small view. However, above 500px high apps start to become unwieldy at typical browser viewport sizes.
  • It is theoretically possible for an app to use an inner scrollbar to constrain the height of the app, but in general we discourage this. It is easier for the user to control scrolling of the browser window than inside an individual app, and scrollbars add visual clutter.


  • Users can apply various "themes" to their My Yahoo! pages, and the small view of an app on My Yahoo! will automatically inherit the styles associated with these themes (including text, link, and background colors).
  • As a general rule, we discourage app developers from explicitly setting font or background colors so that the app will feel like a "natural" part of the user’s page.
  • If you absolutely must set colors for part or all of your app’s small view, be sure to set both foreground and background colors. Otherwise, you could end up with an unreadable mess (for example, black text from your app on a black background from the user’s theme).


  • Users can choose from a range of base font sizes for their My Yahoo! pages. Therefore, we recommend that you set font sizes as percentages rather than providing pixel or point sizes.
  • My Yahoo! mostly uses Arial / Helvetica fonts. If you want to specify a specific font face, please provide a degradation path in your font-family specification.

Distributing apps to My Yahoo! users

There are several ways for users to discover the great apps you build.

Direct distribution

You can distribute your apps by posting "Add to Yahoo!" buttons anywhere on the web. See Application Distribution and Promotion for more information.

User-to-user sharing

The standard YAP user interface includes an "Options" menu with a "Share" feature that allows users to share apps with their connections. You can also use the yml:share tag to create a user-to-user sharing form in the canvas view of your app.


As users install and use apps, update events are generated. These events show up in various places around Yahoo! as messages like "James is now using Super Fun App". In these messages, the app title is a link to the canvas view of your app, and at top right of each canvas page is an "Add to My Yahoo!" link.


In addition to the above "self-service" distribution mechanisms, we will be highlighing selected apps in the My Yahoo! content gallery. In the future, we will roll out a process for submitting apps to the My Yahoo! content gallery.

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