# Go App Engine SDK 1.5.5 released 11 Oct 2011 Tags: appengine, gofix, release Summary: Go App Engine SDK 1.5.5 includes Go release.r60.2. OldURL: /go-app-engine-sdk-155-released Andrew Gerrand ## Today we released version 1.5.5 the Go App Engine SDK. You can download it from the [App Engine downloads page](http://code.google.com/appengine/downloads.html). This release includes changes and improvements to the App Engine APIs and brings the supporting Go tool chain to [release.r60.2](https://golang.org/doc/devel/release.html#r60) (the current stable release). Also included in this release are the [godoc](https://golang.org/cmd/godoc/), [gofmt](https://golang.org/cmd/gofmt/), and [gofix](https://golang.org/cmd/gofix/) tools from the Go tool chain. They can be found in the root directory of the SDK. Some changes made in this release are backwards-incompatible, so we have incremented the SDK `api_version` to 3. Existing apps will require code changes when migrating to `api_version` 3. The gofix tool that ships with the SDK has been customized with App Engine-specific modules. It can be used to automatically update Go apps to work with the latest appengine packages and the updated Go standard library. To update your apps, run: /path/to/sdk/gofix /path/to/your/app The SDK now includes the appengine package source code, so you can use the local godoc to read App Engine API documentation: /path/to/sdk/godoc appengine/datastore Get **Important note:** We have deprecated `api_version` 2. Go apps that use `api_version` 2 will stop working after 16 December 2011. Please update your apps to use `api_version` 3 before then. See the [release notes](http://code.google.com/p/googleappengine/wiki/SdkForGoReleaseNotes) for a full list of changes. Please direct any questions about the new SDK to the [Go App Engine discussion group](http://groups.google.com/group/google-appengine-go).