Introduction: A Swift and Kotlin library for making composable state machines, and UIs driven by those state machines.
More: Author   ReportBugs   OfficialWebsite   

Kotlin CI Maven Central GitHub license Kotlinlang slack

A unidirectional data flow library for Kotlin and Swift, emphasizing:

  • Strong support for state-machine driven UI and navigation.
  • Composition and scaling.
  • Effortless separation of business and UI concerns.

This project is currently in development and the API subject to breaking changes without notice. Follow Square's engineering blog, The Corner, to see when this project becomes stable.

While the API is not yet stable, this code is in heavy production use in Android and iOS apps with millions of users.

Using Workflows in your project

Maven Artifacts

Artifacts are hosted on Maven Central. If you're using Gradle, ensure mavenCentral() appears in your repositories block, and then add dependencies on the following artifacts:

Maven Coordinates Depend on this if…
com.squareup.workflow1:workflow-core-jvm:x.y.z You are writing a library module/project that uses Workflows, but you don't need to interact with the runtime from the outside.
com.squareup.workflow1:workflow-rx2:x.y.z You need to interact with RxJava2 from your Workflows.
com.squareup.workflow1:workflow-testing-jvm:x.y.z You are writing tests. This should only be included as a test dependency.
com.squareup.workflow1:workflow-ui-core-android:x.y.z You're writing an Android app that uses Workflows.
com.squareup.workflow1:workflow-ui-modal-android:x.y.z Your Android app uses modals (popups).
com.squareup.workflow1:workflow-ui-backstack-android:x.y.z Your android app uses backstacks.

Lower-level Artifacts

Most code shouldn't need to depend on these directly. They should generally only be used to build higher-level integrations with UI frameworks.

Maven Coordinates Depend on this if…
com.squareup.workflow1:workflow-runtime-jvm:x.y.z You need to interact directly with the runtime, i.e. streams of renderings and outputs.
com.squareup.workflow1:workflow-ui-core-jvm:x.y.z You are writing workflow-ui-android for another UI framework. Defines the core types used by that artifact.

Jetpack Compose support

Jetpack Compose is the new (under-development, pre-release) UI toolkit for Android. It is comparable to SwiftUI for iOS. The main UI artifacts in this repository support standard Android Views, but various types of Compose integrations are provided in the sidecar repository square/workflow-kotlin-compose. See that repo for usage info and documentation.


Support & Contact

Workflow maintainers hang out in the #squarelibraries channel on the Kotlin Slack.

Releasing and Deploying



Copyright 2019 Square Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
See the License for the specific language governing permissions and
limitations under the License.
About Me
GitHub: Trinea
Facebook: Dev Tools