Callback Handler that writes to a Streamlit app.
This CallbackHandler is geared towards
use with a LangChain Agent; it displays the Agent's LLM and tool-usage "thoughts"
inside a series of Streamlit expanders.
Parameters
parent_container
The st.container that will contain all the Streamlit elements that the
Handler creates.
max_thought_containers
The max number of completed LLM thought containers to show at once. When this
threshold is reached, a new thought will cause the oldest thoughts to be
collapsed into a "History" expander.
expand_new_thoughts
Each LLM "thought" gets its own st.expander. This param controls whether that
expander is expanded by default.
collapse_completed_thoughts
If True, LLM thought expanders will be collapsed when completed.
thought_labeler
An optional custom LLMThoughtLabeler instance. If unspecified, the handler
will use the default thought labeling logic.
Returns:
A new StreamlitCallbackHandler instance.
Note that this is an "auto-updating" API: if the installed version of Streamlit
has a more recent StreamlitCallbackHandler implementation, an instance of that class
will be used.
