Any value that can be converted to a workflow node: a node, a tool, a plain function, or the 'START' sentinel literal. (Agent wrapping is added in Phase 3 via build_node.)
'START'
build_node
Any value that can be converted to a workflow node: a node, a tool, a plain function, or the
'START'sentinel literal. (Agent wrapping is added in Phase 3 viabuild_node.)