Ignore or hide span via tag

[maxfriedrich]

Describe the feature or potential improvement

Hi, we're using LangGraph with Langfuse. LangGraph is adding steps like __start__, ChannelWrite<...>, __end__ to the execution, see e.g. this screenshot from Langfuse docs:

Think these are not useful most of the time and contain a lot of duplicated data, e.g. a ChannelWrite always has input == output, which is also the output of the node that it belongs to. LangGraph is marking them with a tag "langsmith:hidden". I'm not sure what LangSmith does with that tag, I guess either skip uploading traces or just hide in the UI?

The "langsmith:hidden" tag is also used by some other projects, see https://github.com/search?q=+langsmith%3Ahidden&type=code&p=1, it could make sense to reuse it. What do you think?

Additional information

No response

[marcklingen]

Great feedback! I think mapping these to log-levels in langfuse makes sense in order to be able to hide them in the UI in the future

[marcklingen]

Tracking this here: #5019

[ichina]

@maxfriedrich thank you, i was about to report exactly the same idea.
@marcklingen just for a context, here is how langsmith filter these "internal" spans out:

Screen.Recording.2025-01-14.at.9.54.03.PM.mov

would be brilliant to have something similar in langfuse

[hassiebp]

@maxfriedrich @ichina We have just released v.2.57.9 of our Python SDK (JS up next) that adds the observation level DEBUG to all spans with langsmith:hidden tag. In the UI, you can then filter the trace tree by minimum observation level:

[maxfriedrich]

Thank you! I was able to try it on our traces, looks great!

[ichina]

@hassiebp thank you very much! i confirm it it works on my side!