—Commitments based on branching time logic are powerful representations for modeling multi-agent interactions. Current approaches into commitments have conceived these representations and evolved the commitments as “world-wide” states called moments. These approaches do not capture the space and space-like dimensions and ignore the causal relation between the participating agents. This paper presents a significant step towards developing a new logical semantics of social commitments based on Branching Space-Time (BST) logic. The contributions of this paper are threefold: first, we reformulate BST-logic from philosophical perspective to computational logic being used in computer science discipline; second, we enhance this logic with social commitments (propositional and conditional) and space-like modalities; and third, we present a new semantics model for social commitments and twoparty operations that manipulate commitments in the same framework. Keywords-Branching Space-Time, ...