Theia Extensions and Plugins

Hi All,

We’re using Eclipse Theia for one of internal application development and we’re currently adding a lot of Theia extensions as per our use case.

This has as expected caused our build times to increase and the Theia framework getting slower as more extensions are added as our development proceeds.

I recently came by the concept of Theia plugins and thought that maybe instead of writing extensions we can write user installable plugins but the Theia documentation ( does not instill much confidence regarding plugin support for the future.

Is there maybe any way we can lazy load our extensions at runtime perhaps?

Thanks & Regards,

Hey @vatsal.uppal,

note that what we call Theia “plugins” are essentially just slightly modified vscode extensions. Theia offers support for most of the vscode extension API and we plan on continuing our efforts to catch up to vscode. See our API comparison report.

In that sense, while writing Theia plugins itself is not really recommended (as stated by the documentation), developing and then installing vscode extensions very much is recommended! Be aware that the vscode extension API provides far less/more restricted API surface compared to writing a Theia extension, due to the difference in architecture (runtime installable or compiled respectively).

Theia framework getting slower

This shouldn’t be the case unless you’re doing a lot of work in awaited initialization functions (which should always be kept at a minimum). Bundlesize/Applicationsize shouldn’t really have an impact on runtime performance of Theia. Were you able to identify specific bottlenecks that lead to performance degradation?