On the github page https://github.com/aws-amplify/aws-sdk-android it says:
For new projects, we recommend interacting with AWS using the Amplify Framework.
On the Amplify Framework page about JS developement (https://docs.amplify.aws/lib/q/platform/js), there's a library called PubSub that should do MQTT connection.
But if I switch to Android developement (https://docs.amplify.aws/lib/q/platform/android), that option is not there anymore.
Is there a way to use MQTT with Amplify and GraphQL? Or I need to refer to the android aws sdk and more specifically to this example: https://github.com/awslabs/aws-sdk-android-samples/blob/main/AndroidPubSub/src/com/amazonaws/demo/androidpubsub/PubSubActivity.java
Yes, you can use the AWS IoT SDK for Android. The AWS IoT SDK uses MQTT as its messaging transport. An example use is here. The source code is here. Here is the artifact in maven.