# Generate code for devices
<a name="managedintegrations-sdk-codegen-generate"></a>

Create customized C code for your devices using the Managed Integrations code generation tools. This section describes how to generate code from sample files included with the SDK or from your own specifications. Learn how to use the generation scripts, understand the workflow process, and create code that matches your device requirements.

**Topics**
+ [Prerequisites](#managedintegrations-sdk-codegen-genprereq)
+ [Generate code for custom .matter files](#managedintegrations-sdk-codegen-genspecfile)
+ [Code generation workflow](#managedintegrations-sdk-codegen-genworkflow)

## Prerequisites
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1. Python 3.10 or higher.

2. Start with a .matter file for code generation. The End device SDK provides two sample files in the `codgen/matter_files folder`:
+ `custom-air-purifier.matter `
+ `aws_camera.matter`

**Note**  
These sample files generate code for demo application clusters.

**Generate code**  
Run this command to generate code in the out folder:

```
bash ./gen-data-model-api.sh
```

## Generate code for custom .matter files
<a name="managedintegrations-sdk-codegen-genspecfile"></a>

To generate the code for a specific `.matter` file or provide your own `.matter` file, perform the following tasks.

**To generate the code for custom .matter files**

1. Prepare your .matter file

1. Run the generation command:

   ```
   ./codegen.sh [--format] configs/dm_basic.json path-to-matter-file output-directory
   ```

**(Optional) To generate code with custom schema**

1. Prepare your custom schema in `JSON` format

1. Run the generation command:

   ```
   ./codegen.sh [--format] configs/dm_basic.json path-to-matter-file output-directory --custom-schemas-dir path-to-custom-schema-directory
   ```

The above commands uses several components to transform your `.matter` file into `C` code:
+ `codegen.py` from the **ConnectedHomeIP** project
+ Python plugin located at `codegen/py_scripts/iotmi_data_model.py`
+ Jinja2 templates from the `codegen/py_scripts/templates` folder

The plugin defines the variables to pass to the Jinja2 templates, which are then used to generate the final C code output. Adding the `--format` flag applies the Clang format to the generated code.

## Code generation workflow
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The code generation process organizes your .matter file data structures using utility functions and topological sorting through `topsort.py`. This ensures proper ordering of data types and their dependencies.

The script then combines your .matter file specifications with Python plugin processing to extract and format the necessary information. Finally, it applies Jinja2 template formatting to create the final C code output.

This workflow ensures that your device-specific requirements from the .matter file are accurately translated into functional C code that integrates with the Managed Integrations system.