How to start system projection with ProjectionsManager

a fresh EventStore instance that is running with --run-projections=ALL seems to have all system projections in a stopped state.

I’m sure there are good reasons for that and it is easy to start those manually via the WebUI, but I’d like to start one of them ($by-event-type) from code via ProjectionsManager (for initialization scripts etc.).

While it was easy to create a new projection with ProjectionsManager, EnableAsync does not seem to find it, neither with name “$by-event-type”, nor “by-event-type”.

What would be the preferred way to start those? Is EnableAsync even the correct method for starting a system projection?



you might have to try %24by-event-type off the top of my head (would
have to test it to provide exact code for you which I can likely do
later today or tomorrow)

Unfortunately exchanging %24 for the dollar sign did not work, got 404 Not Found.
But this issue has very low priority as I can easily enable it on-demand, so anytime in the next week or so will be totally fine.

if you want to see what gets sent you can probably just run fiddler
and try from browser :slight_smile:

Fiddler said


“msgTypeId”: 237,

“name”: “$by_event_type”


But while writing this answer I noticed that I used hyphens instead of underscores (oops), now it works fine :slight_smile: thanks!

Great, glad you found it.