This paper introduces multiparty asynchronous session types, extending binary session types to support communication among multiple parties in asynchronous settings. Session types provide a typed foundation for structured communication-centered programming, ensuring communication safety, progress, and session fidelity. The proposed theory introduces global types that abstract interactions involving multiple peers as a single global scenario, retaining the intuitive syntax of binary session types while capturing complex causal chains of interactions. Global types serve as a shared agreement among communication peers and are used for efficient type-checking through projections onto individual peers. The theory establishes fundamental properties such as communication safety, progress, and session fidelity for general n-party asynchronous interactions. The work is motivated by the need to formalize End-Point Projection (EPP) in the Web Services Choreography Description Language (WS-CDL), which describes global protocols for business interactions. The paper presents a typed calculus for mobile processes, introducing three major technical contributions: (1) a new notion of types that abstract global scenarios among n-parties, (2) consistency criteria for conversation structures based on causality analysis of actions in global types, and (3) a type discipline for individual processes using global types through their projections onto individual endpoints. The paper provides examples of multiparty sessions, including a two-buyer protocol and a streaming protocol, demonstrating how global types can be used to model and validate complex interactions. The operational semantics of the calculus is defined through a reduction relation, capturing the behavior of sessions in asynchronous communication. The paper also discusses the challenges of multiparty asynchronous sessions, including the need for effective abstraction of global scenarios and ensuring linearity of channel usage. The proposed theory is applied to a variety of programming languages and computing environments, including mobile processes, higher-order processes, ambients, and web services. The paper concludes with a discussion of future research directions and applications of the theory in industry and academia.This paper introduces multiparty asynchronous session types, extending binary session types to support communication among multiple parties in asynchronous settings. Session types provide a typed foundation for structured communication-centered programming, ensuring communication safety, progress, and session fidelity. The proposed theory introduces global types that abstract interactions involving multiple peers as a single global scenario, retaining the intuitive syntax of binary session types while capturing complex causal chains of interactions. Global types serve as a shared agreement among communication peers and are used for efficient type-checking through projections onto individual peers. The theory establishes fundamental properties such as communication safety, progress, and session fidelity for general n-party asynchronous interactions. The work is motivated by the need to formalize End-Point Projection (EPP) in the Web Services Choreography Description Language (WS-CDL), which describes global protocols for business interactions. The paper presents a typed calculus for mobile processes, introducing three major technical contributions: (1) a new notion of types that abstract global scenarios among n-parties, (2) consistency criteria for conversation structures based on causality analysis of actions in global types, and (3) a type discipline for individual processes using global types through their projections onto individual endpoints. The paper provides examples of multiparty sessions, including a two-buyer protocol and a streaming protocol, demonstrating how global types can be used to model and validate complex interactions. The operational semantics of the calculus is defined through a reduction relation, capturing the behavior of sessions in asynchronous communication. The paper also discusses the challenges of multiparty asynchronous sessions, including the need for effective abstraction of global scenarios and ensuring linearity of channel usage. The proposed theory is applied to a variety of programming languages and computing environments, including mobile processes, higher-order processes, ambients, and web services. The paper concludes with a discussion of future research directions and applications of the theory in industry and academia.