Overview

FastScript .NET is a lightweight, cross-platform scripting library designed for executing complex C# scripts in environments without code generation support, such as Native AOT, WASM, and iOS. Unlike traditional scripting solutions like CodeDOM or Roslyn, FastScript .NET uses an interpreter model that does not require generating separate DLL files. This allows script execution in resource-constrained or security-critical environments.

Features and Capabilities

• **Cross-Platform Execution: **FastScript .NET runs smoothly on multiple platforms including those that do not support dynamic code generation, such as Native AOT (Ahead-Of-Time compilation), WebAssembly (WASM), and iOS environments. This makes it ideal for modern, resource-restricted, or sandboxed applications.
• **Full C# Language Support with Key Modern Features: **Supports the core features of C# 1.0 and many advanced language constructs including classes, structs, enumerations, delegates, events, interfaces, and inheritance. This allows developers to write complex and structured scripts that feel like standard C# code.
• **Interpreted Script Execution Model: **Unlike traditional scripting tools that generate and compile assemblies or DLLs, FastScript .NET uses an interpreter engine to execute scripts on the fly. This eliminates the need for intermediate binaries, reducing disk I/O and security risks.
• **Memory and Performance Optimizations: **Designed with a cache-based execution engine that minimizes memory consumption and improves performance by reusing parsed scripts. The lightweight 300 KB library footprint makes it perfect for embedded and lightweight applications.
• **Security Controls and Sandboxing: **Provides fine-grained control over script execution, including the ability to restrict access to unsafe or unmanaged APIs, whitelist or blacklist assemblies, namespaces, or specific types. This helps in creating secure scripting environments preventing malicious or unintended code execution.
• **Deep Integration with .NET Ecosystem: **FastScript .NET integrates seamlessly with any .NET application, allowing scripts to interact with .NET libraries, frameworks, and APIs. This enables the extension of host applications dynamically through scripting, supporting plugins, macros, and user-customizable logic.
• **Support for Complex Programming Constructs: **Includes support for multi-threading, exception handling, type reflection, generic methods, lambda expressions, and delegates, empowering developers to write sophisticated scripts that can handle advanced logic and workflows.
• **Ease of Embedding and Extensibility: **The API design facilitates easy embedding of FastScript into existing .NET applications. Developers can expose custom host objects, methods, and properties to scripts, enabling deep customization and extension of application behavior through scripting.
• **No External Dependencies: **The engine is self-contained and does not rely on external compilers or runtimes, simplifying deployment in environments with strict deployment requirements or limited access to runtime compilers.
• **Ideal for Plugin and Automation Scenarios: **Because it allows executing dynamic C# code securely without code generation, it is perfect for applications requiring user scripting, plugin support, automation workflows, or custom business rules.