LangchainCallbackHandler custom input/output?

[willow hemlock]

Is there a way to set/override input/output when using the LangchainCallbackHandler similar to how the @observe() decorator allows updating observation context with custom inputs/outputs?

[zinc elk]

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[ivory skiff]

Overriding single observation/span/generation outputs is tricky. You could fetch the trace via the fetch_* methods to then update it.

If you want to change the trace output you could wrap this with the decorator and handle the trace yourself. Details: https://langfuse.com/docs/integrations/langchain/tracing#interoperability

What do you try to achieve here? Maybe I can help in a better way with more context

[zinc elk]

Thank you for marking this question as solved!

[willow hemlock]

I wanted to explore truncating the input/output to a certain length on certain conditions so we don't persist too much into the DB.