Jint is a JavaScript interpreter for .NET that executes ECMAScript code directly within your .NET process without requiring native dependencies, bytecode compilation, or an external runtime.
The tool solves the problem of running JavaScript in server-side .NET applications by embedding a complete ECMAScript interpreter written in managed code. It allows you to evaluate JavaScript expressions, expose .NET objects and methods to scripts, and invoke JavaScript functions from C#. The interpreter supports modern language features including modules, promises, async functions, generators, and the Intl and Temporal APIs. Prepared scripts and modules are thread-safe and can be reused across engine instances, making it efficient for scenarios where the same code runs repeatedly.
Jint suits applications that need to execute untrusted or user-supplied JavaScript safely within a .NET host. It works well for dynamic scripting in content management systems, workflow engines, and document processing tools. The project emphasizes security by defaulting to hardened restrictions on untrusted code and requiring hosts to explicitly grant capabilities like browser or Node APIs rather than enabling them by default. If you need debugging support, the DevTools package provides Chrome DevTools Protocol integration for profiling and inspection. For browser automation or DOM manipulation, the optional Browser package adds headless HTML rendering and navigation. The tool targets multiple .NET versions including Framework 4.7.2, Standard 2.0 and 2.1, and .NET 8 and 10.
Development activity shows sustained focus on standards compliance and feature completeness. The project maintains multiple support branches with the 4.x line handling compatibility-preserving fixes while the main branch develops the next major version with breaking changes. Execution constraints and security diagnostics are actively refined to support safe execution of untrusted code. The tool includes profiling, statement coverage, and debugging capabilities alongside optional command-line and Model Context Protocol server interfaces for different integration scenarios.
