Input/Output (I/O) logic is a general framework for reasoning about conditional norms and/or causal relations. We streamline Bochman’s causal I/O logics and their original version via proof-search-oriented sequent calculi. As a byproduct, we obtain new, simple semantics for all these logics, complexity bounds, embeddings into normal modal logics, and efficient deduction methods. Our work encompasses many scattered results and provides uniform solutions to various unresolved problems.