Clarification: Deprecation Policy for Browser Extensions

[hanguokai]

Chrome has its deprecation policy for Web, and I think other browsers also have it. But that policy is for Web, not for extensions.

Because Web is standardized, Web apis are long term support(LTS). But what does extensions apis look like?

• A) Extensions apis are long term support. Keep compatibility as the highest priority and avoid break changes as much as possible.
• B) There is no guarantee of compatibility between main versions, and breaking changes may occur at any time.

The purpose of this issue is to hope that browser vendors clarify their deprecation policy for extension apis. This will help improve developers' confidence in using extension apis.

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Below is a copy of Chrome's deprecation policy for Web.

To keep the platform healthy, we sometimes remove APIs from the Web Platform which have run their course. There can be many reasons why we would remove an API, such as:

• They are superseded by newer APIs.
• They are updated to reflect changes to specifications to bring alignment and consistency with other browsers.
• They are early experiments that never came to fruition in other browsers and thus can increase the burden of support for web developers.

Some of these changes will have an effect on a very small number of sites. To mitigate issues ahead of time, we try to give developers advanced notice so they can make the required changes to keep their sites running.

Chrome currently has a process for deprecations and removals of API's, essentially:

• Announce on the blink-dev mailing list.
• Set warnings and give time scales in the Chrome DevTools Console when usage is detected on the page.
• Wait, monitor, and then remove the feature as usage drops.

You can find a list of all deprecated features on chromestatus.com using the deprecated filter and removed features by applying the removed filter. We will also try to summarize some of the changes, reasoning, and migration paths in these posts.

[xeenon]

Apple sees extension APIs as long term support.