The streaming modes enabled for this graph. Defaults to ["values"].
Supported modes:
- "values": Streams the full state after each step
- "updates": Streams state updates after each step
- "messages": Streams messages from within nodes
- "custom": Streams custom events from within nodes
- "tools": Streams tool-call lifecycle events (on_tool_start, on_tool_event, on_tool_end, on_tool_error) from LLM tool execution
- "debug": Streams events related to the execution of the graph - useful for tracing & debugging graph execution
