> For the complete documentation index, see [llms.txt](https://notes.tejpratapsingh.com/android-tips/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://notes.tejpratapsingh.com/android-tips/gradle/create-custom-build-config-variables.md).

# Create Custom Build Config Variables

```gradle
android {
    buildTypes {
        def localProperties = new Properties()
        localProperties.load(new FileInputStream(rootProject.file("local.properties")))
        
        debug {
            buildConfigField("String", "API_KEY", "\"" + localProperties['apiKey'] + "\"")
        }
        release {
            buildConfigField("String", "API_KEY", "\"" + localProperties['apiKey'] + "\"")
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}
```