JBang Jash, introduced by the JBang team, is a Java library that simplifies the execution of external processes and shell commands through a fluent and predictable API.
It aims to address complexities faced by developers when using standard Java APIs for process execution, providing chainable process execution, automatic input/output stream handling, and customizable handling of non-zero exit codes.
JBang Jash also supports piping commands in a pipeline, detects the appropriate shell environment, and offers an intuitive interface for working with shell processes and streams in Java 17+.
The project, originally named 'fluent-process' by OnGres, Inc. in 2020, was forked and renamed to 'jash' in 2025 to provide a more idiomatic Java interface for shell processes. Jash can be integrated into any Java project without the need for the JBang CLI tool.