Session types are type-theoretic specifications of communication protocols in concurrent or distributed systems. By codifying the structure of communication, they make software more reliable and easier to construct. Over recent decades, the topic has become a large and active research area within the field of programming language theory and implementation. Written by leading researchers in the field, this is the first text to provide a comprehensive introduction to the key concepts of session types. The thorough theoretical treatment is complemented by examples and exercises, suitable for use in a lecture course or for self-study. It serves as an entry point to the topic for graduate students and researchers.

‘This book on session types, one of most fruitful and successful topics in concurrency theory over the past 30 years, is written with great clarity, deep insight, and enthusiasm by two of most renowned researchers in the field. It is a most welcomed text, both for learning from and for teaching. It offers a comprehensive account of the basic theory and explains the possible applications, beautifully leavened with insightful examples and exercises. It will become -- and well deserves to become - the definitive reference textbook on session types.’

Davide Sangiorgi - University of Bologna

‘How should we structure distributed computation? One of the most promising approaches is Session Types. Here we have a superb introduction by two founders of the field. Gay and Vasconcelos provide a readable yet thorough introduction. It has long been needed, and will help the field flourish.’

Philip Wadler - University of Edinburgh

‘This book offers a deep view on the core theory of binary session types. The reader is captivated by the appropriate and clarifying examples and stimulated by the challenging exercises. The authors are outstanding researchers as witnessed by the simplicity and rigour of their writing.’

Mariangiola Dezani-Ciancaglini - University of Turin

‘Session types codify communication structures of concurrent and distributed programs, guiding the programmer to write type and communication safe programs. This book explains binary session types starting from basics to advance, making it accessible to students, newcomers and programmers at the industry alike.’

Nobuko Yoshida - University of Oxford