Gradle can be a really intimidating build tool to get started on. One of the concepts that baffled me in the beginning was repositories {} blocks throughout a Gradle project that contain a list of usually maven repositories used by Gradle to download artifacts. I could not make heads or tails of it, so I decided to share about it and helpfully help you understand it better.

First thing to be aware of that there are generally two types of repositories lists in Gradle: plugin vs build. You can think of these of “how to build things” vs “what to build against”. Plugin repositories are used to find where to find (surprise surprise…) Gradle plugins such as spotless or kotlin. Whereas build repositories are used to find what you want to use for your libraries, such as dependencies on kotlin-stdlib or guava.

Now that we have these two different definitions — the recommended way to set these are in your settings.gradle.kts with:

// plugin repositories
pluginManagement {
    repositories {
        mavenCentral()
        gradlePluginPortal()
        google()
    }
}
// build repositories
dependencyResolutionManagement {
    repositories {
        mavenCentral()
        google()
    }
}

pluginManagement {} block will be used to resolve entries like

plugins {
    id("com.android.application") version "7.2.0" apply false
}

and dependencyResolutionManagement {} block is used to resolve entries like

dependencies {
    implementation("com.google.guava:guava:31.1-jre")
}

However, given the title of this article you probably have already realized that these are not the only places where you can set repositories. You can head over to the sample GitHub repo to look at settings.gradle.kts and build.gradle.kts to see other places where you can use repositories {} and why you might want to do so.