  This paper considers the problem of controller synthesis of signal temporal
logic (STL) specifications for large-scale multi-agent systems, where the
agents are dynamically coupled and subject to collaborative tasks. A
compositional framework based on continuous-time assume-guarantee contracts is
developed to break the complex and large synthesis problem into subproblems of
manageable sizes. We first show how to formulate the collaborative STL tasks as
assume-guarantee contracts by leveraging the idea of funnel-based control. The
concept of contracts is used to establish our compositionality result, which
allows us to guarantee the satisfaction of a global contract by the multi-agent
system when all agents satisfy their local contracts. Then, a closed-form
continuous-time feedback controller is designed to enforce local contracts over
the agents in a distributed manner, which further guarantees the global task
satisfaction based on the compositionality result. Finally, the effectiveness
of our results is demonstrated by two numerical examples.
