topic Re: New RUM - Custom event and session properties in Real User Monitoring

New RUM - Custom event and session properties

reshef — Mon, 27 Apr 2026 11:34:16 GMT

Hi,
We have just moved to the new RUM experience, and much to my surprise the new frontend settings for Event and session properties does not seem to include the option to add custom properties - unless via the JS RUM API. Is that really the case?

We're relying heavily on session and user action properties in our frontend monitoring, mostly with CSS selectors, and we don't always have the option to modify the code in these applications (for example with out of the box services like SAP and Tableau).

Re: New RUM - Custom event and session properties

t_pawlak — Mon, 02 Feb 2026 16:20:38 GMT

Hi,

In the New RUM Experience, Event and session properties for web frontends:

must be configured/defined first, otherwise incoming properties are dropped during ingest,
and the documented way to provide values is via the JS RUM API (addEventModifier for event properties, sendSessionPropertyEvent for session properties).
there are explicit limits (for example max 20 configured properties, naming/value limits).

Everything you can find here: https://docs.dynatrace.com/docs/observe/digital-experience/new-rum-experience/web-frontends/additional-configuration/event-and-session-properties

Given you rely heavily on CSS-selector-based action/session properties and often can’t modify application code (for example SAP and Tableau), the important nuance is:

New RUM currently runs alongside RUM Classic, and you can’t fully migrate away from Classic yet.
Event & session properties are explicitly separate from RUM Classic “user action & session properties” (the Classic ones are where CSS selector capture lives).

Here documentation where everything is explain: https://docs.dynatrace.com/docs/observe/digital-experience/new-rum-experience/relationship-to-rum-classic

So in practice:

DOM/CSS selector / meta-tag style capture → keep using RUM Classic user action & session properties.
New RUM event & session properties → effectively require JS API; without a way to inject or run custom JS, they won’t replace your selector-based setup 1:1.

Re: New RUM - Custom event and session properties

michiel_otten — Thu, 28 May 2026 14:50:52 GMT

Will the new RUM event & session properties also include CSS & DOM selectors in the future (as well as request attributes)? Do we know if it's on the roadmap?
These were massive benefits of Dynatrace since not everyone is willing to edit their code.

Re: New RUM - Custom event and session properties

y_buccellato — Thu, 28 May 2026 15:21:00 GMT

I noticed and mentioned the same thing in another similar post, but it seems it went unnoticed 😄

While I understand your explanation, it would be helpful for us to have a clearer statement going forward:

Will the new RUM support capturing CCS, cookies, etc., to create user tags, session properties, and event properties?

Or is the new development intended to follow this current approach permanently?

I am in the same situation of michiel here.

Re: New RUM - Custom event and session properties

simon_schatka — Fri, 29 May 2026 13:45:00 GMT

yes, css and dom selectors will come again, so you can configure that in the UI again. It will also be made a bit more powerful (we will simplify the parsing of strings as JSON, which was possible in RUM classic at some point, but is a bit cumbersome) and we will also allow accessing properties with a "." in their name (a corner case, but was a use case for some customers).
This is on the roadmap for the June Rally (as well as cookie capturing if you are interested).

Request attributes are currently not planned though.