ModDevGradle

DevLogin is integrated into ModDevGradle starting from version 2.0.63-beta+.

For more details, refer to their documentation.

For ModDevGradle 2.0.62-beta (or older)

Step 1: Add maven repository:

groovy (build.gradle)

repositories {
    maven { url 'https://maven.covers1624.net/' }
}

kotlin (build.gradle.kts)

repositories {
    maven("https://maven.covers1624.net/")
}

Step 2: Add runtime dependency:

groovy (build.gradle)

dependencies {
    runtimeOnly 'net.covers1624:DevLogin:0.1.0.5'
}

kotlin (build.gradle.kts)

dependencies {
    runtimeOnly("net.covers1624:DevLogin:0.1.0.5")
}

Step 3: Add run configuration:

groovy (build.gradle)

minecraft {
    runs {
        clientAuthed {
            client()
            mainClass = 'net.covers1624.devlogin.DevLogin'
            programArguments.addAll('--launch_target', 'cpw.mods.bootstraplauncher.BootstrapLauncher')
        }
    }
}

kotlin (build.gradle.kts)

minecraft {
    runs {
        clientAuthed {
            client()
            mainClass = "net.covers1624.devlogin.DevLogin"
            programArguments.addAll("--launch_target", "cpw.mods.bootstraplauncher.BootstrapLauncher")
        }
    }
}