# Compile a static library as a Unity plug-in

> Call functions from a static library.

You can compile libraries with Emscripten and use the libraries in Unity. It can be more beneficial to call functions from libraries that encapsulate C++ code rather than C++ code directly from the plug-in directory. The benefits include:

* Your code is easier to integrate with your Web Unity project.
* Your code can perform better than if you call functions from C++ code, especially for larger libraries.
* You can reuse the code in various projects.

## Steps to use a static library in Unity

To compile a static library that you can use as a Unity plug-in:

1. [Download the Emscripten SDK](#download-emscripten)
2. [Configure any existing project scripts](#configure-compiler)
3. [Update your compiler options](#compiler-options)
4. [Compile and import your static library files](#import-c-files)
5. [Call your static library functions from C# scripts](#call-static-libr)

### 1. Download the Emscripten SDK

You must download the Emscripten SDK that matches your version of Unity.

To find the appropriate version of Emscripten for your Unity version, refer to [Web native plug-ins for Emscripten](/engine/6000.3/manual/platform-specific/webgl/develop/native-plugins-with-emscripten.md).

For download links and more information about how to install the Emscripten SDK, refer to [Download and install](https://emscripten.org/docs/getting_started/downloads.html) (Emscripten).

### 2. Configure any existing project scripts

Emscripten works as a replacement for the gcc or clang compiler. If you have existing C/C++ code, you need to make the following changes in your C++ project:

* Use "emcc" as the C/C++ compiler
* Use "emar" as the static linker

For more information, refer to the Emscripten documentation on [Compiling and Running Projects](https://emscripten.org/docs/compiling/index.html).

### 3. Update your compiler options

You might need to add some compiler options to your C/C++ project if your Unity project has the following **Player** settings (menu: **Edit** > Editor > **Player**).

| Property                               | Description                                                                                                                                                                 |
| -------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Enable Exceptions**                  | If this property is set to **None**, add the compiler option “-fno-exceptions”.                                                                                             |
| **Enable Native C/C++ Multithreading** | If this property is enabled, include the compiler option “-pthread”.                                                                                                        |
| **Enable WebAssembly 2023**            | If this property is enabled, include the following compiler options:"-fwasm-exceptions""-sSUPPORT\_LONGJMP=wasm""-mbulk-memory""-mnontrapping-fptoint""-msimd128""-msse4.2" |

### 4. Compile and import your static library files

Compile your static library files and then import your files into your Unity project in the `Assets/Plugins` folder.

> **Note:**
>
> If you don't have a **Plugins** folder, you need to create your own.

### 5. Call your static library functions from Unity C# scripts

You can call your static library functions from your Unity C# scripts. The way to call the functions is the same as if you call a C or C++ function from C# scripts. For an example, refer to [Call C/C++/C# functions from Unity C# scripts](/engine/6000.3/manual/platform-specific/webgl/develop/interactingwithbrowserscripting/web-interacting-browsers-c-to-unity.md).

## Additional resources

* [Interaction with browser scripting](/engine/6000.3/manual/platform-specific/webgl/develop/interactingwithbrowserscripting.md)

* [Set up your JavaScript plug-in](/engine/6000.3/manual/platform-specific/webgl/develop/interactingwithbrowserscripting/web-interacting-browser-js.md)

* [Call JavaScript functions from Unity C# scripts](/engine/6000.3/manual/platform-specific/webgl/develop/interactingwithbrowserscripting/web-interacting-browser-js-to-unity.md)

* [Call Unity C# script functions from JavaScript](/engine/6000.3/manual/platform-specific/webgl/develop/interactingwithbrowserscripting/web-interacting-browser-unity-to-js.md)

* [Create callbacks between Unity C#, JavaScript, and C/C++/C# code](/engine/6000.3/manual/platform-specific/webgl/develop/interactingwithbrowserscripting/web-interacting-browser-example.md)