deploy your webapp to Google App Engine using sbt.
Scala Java
Clone or download
Pull request Compare This branch is 160 commits ahead of goneflyin:master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.
notes 0.8.0 Oct 22, 2017
project sbt 0.13.17 Feb 25, 2018
src fix "target/webapp"): error=2, No such file or directory" error when … Oct 22, 2017
.travis.yml update appengine-java-sdk Feb 25, 2018
build.sbt sbt 0.13.17 Feb 25, 2018
scripted.sbt fix scripted test May 13, 2014

sbt-appengine is a sbt 0.10+ port of the awesome Yasushi/sbt-appengine-plugin.


export environment variables (JREBEL_PATH is optional).

export APPENGINE_SDK_HOME=/Applications/appengine-java-sdk-
export JREBEL_PATH=/Applications/ZeroTurnaround/JRebel/jrebel.jar

If you have problems setting the APPENGINE_SDK_HOME environment variable (for example if you're using IntelliJ), then you can instead create a file with a single line of sdkHome=/Applications/appengine-java-sdk-

setup for sbt 0.13 and sbt 1.x

put the following in the project/appengine.sbt:

addSbtPlugin("com.eed3si9n" % "sbt-appengine" % "0.8.0")

and the following in appengine.sbt:

libraryDependencies += "org.mortbay.jetty" % "jetty" % "6.1.22" % "container"


setup for sbt 0.12




you can deploy your application like this:

> appengineDeploy

development server

to (re)start the development server in the background:

> appengineDevServer

to redeploy development server continuously:

> ~ appengineDevServer

hot loading!

to hot reload development server continuously, set JREBEL_PATH and:

> appengineDevServer
> ~ packageWar

by default development server runs in debug mode. IDE can connect to it via port 1044.

appengineDevServer lifecyle hooks

to run a code on start/stop of dev server:

(appengineOnStartHooks in appengineDevServer in Compile) += { () =>

(appengineOnStopHooks in appengineDevServer in Compile) += { () =>

backend support

you can deploy your backend application(s) like this:

> appengineDeployBackends

to start a backend instance in the cloud:

> appengineStartBackend <backend-name>

to stop a backend instance:

> appengineStopBackend <backend-name>

DataNucleous enhancer support (experimental)

sbt-appengine provides experimental support for DataNucleous enhancer. to use this, include the following in build.sbt:



appenginePersistenceApi in appengineEnhance in Compile := "JDO"

this will call the enhancer automatically on packageWar task. since DataNucleous expects plain Java fields, the entity class looks a bit ugly in Scala:

import javax.jdo.annotations._
import scala.annotation.meta.field

case class Counter(
  @(PrimaryKey @field)
  @(Persistent @field)(valueStrategy = IdGeneratorStrategy.IDENTITY)
  var key: Key,
  @(Persistent @field)
  var count: Int)



When trying to launch the dev server with appengineDevServer, you might run into the following exception: java.lang.RuntimeException: Unable to restore the previous TimeZone. This issue has been resolved in the latest App Engine SDK.