Changing the code for the default system projections?

Hello guys.

Quick question: is there any way for us to see and change the code for the default system projections (ex.: $by_category) on the web UI?

I’m assuming the answer is no but wanted to be sure…




Hi Luis,

The system projections aren’t implemented in JavaScript. You can’t get the code via the web UI, but you can get it off the GitHub repository (
for example).



if i were to make my own IProjectionStateHandler how would i make use of it? Do i need to create my own build ? or is there a place where it will pick up my own assembly?

seems to suggest (if i’m looking in the correct spot) that it will.

You wouldn’t want to

+1 - it’s hard to implement properly. We don’t currently load anything from outside the projections core assembly (which gets ilmerged during build).