Chrome extension API to manipulate other installed Chrome extensions?

Question

I'm writing a Google Chrome extension that needs to do a lot of things with other extensions, such as:

• List installed extensions and read their IDs
• Request extension installation, update and removal (preferably without bothering the user)
• Modify extension settings

and so on. Which of these are possible, and which are not (due to e.g. security considerations)?

P.S. I haven't been able to find answers in the inter-extension messaging section of the official docs (or anywhere else, actually).

Answer 1

Chromium developer Brian Kennish states here suggests writing an NPAPI plugin as the most rational option to achieve the desired effect.

Answer 2

This is not directly possible via the extension API. To be honest, I wouldn't recommend using NPAPI for this either since you'd have to modify files which are in-use by the browser, which is unreliable at best.