Clone this repo:
  1. b1f2635 datastore: fix behavior when ErrConcurrentTransaction occured (#139) by Masahiro Wakame · 8 weeks ago master v1.1.0
  2. b9aad5d datastore: enable to set query batch size (#90) by JINNOUCHI Yasushi · 9 weeks ago
  3. 962cbd1 datastore: add omitempty support for time.Time (#131) by Alexander Trakhimenok · 3 months ago
  4. 0a24098 datastore: add AllocateIDRange (#130) by Michael Traver · 3 months ago
  5. ad39d7f aetest: new option to suppress dev_appserver logs (#119) by Yuki Ito · 4 months ago

Go App Engine packages

Build Status

This repository supports the Go runtime on App Engine standard. It provides APIs for interacting with App Engine services. Its canonical import path is

See for more information.

File issue reports and feature requests on the GitHub's issue tracker.

Upgrading an App Engine app to the flexible environment

This package does not work on App Engine flexible.

There are many differences between the App Engine standard environment and the flexible environment.

See the documentation on upgrading to the flexible environment.

Directory structure

The top level directory of this repository is the appengine package. It contains the basic APIs (e.g. appengine.NewContext) that apply across APIs. Specific API packages are in subdirectories (e.g. datastore).

There is an internal subdirectory that contains service protocol buffers, plus packages required for connectivity to make API calls. App Engine apps should not directly import any package under internal.

Updating from legacy (import "appengine") packages

If you're currently using the bare appengine packages (that is, not these ones, imported via, then you can use the aefix tool to help automate an upgrade to these packages.

Run go get to install it.

1. Update import paths

The import paths for App Engine packages are now fully qualified, based at You will need to update your code to use import paths starting with that; for instance, code importing appengine/datastore will now need to import

2. Update code using deprecated, removed or modified APIs

Most App Engine services are available with exactly the same API. A few APIs were cleaned up, and there are some differences:

  • appengine.Context has been replaced with the Context type from
  • Logging methods that were on appengine.Context are now functions in
  • appengine.Timeout has been removed. Use context.WithTimeout instead.
  • appengine.Datacenter now takes a context.Context argument.
  • datastore.PropertyLoadSaver has been simplified to use slices in place of channels.
  • delay.Call now returns an error.
  • search.FieldLoadSaver now handles document metadata.
  • urlfetch.Transport no longer has a Deadline field; set a deadline on the context.Context instead.
  • aetest no longer declares its own Context type, and uses the standard one instead.
  • taskqueue.QueueStats no longer takes a maxTasks argument. That argument has been deprecated and unused for a long time.
  • appengine.BackendHostname and appengine.BackendInstance were for the deprecated backends feature. Use appengine.ModuleHostnameand appengine.ModuleName instead.
  • Most of appengine/file and parts of appengine/blobstore are deprecated. Use Google Cloud Storage if the feature you require is not present in the new blobstore package.
  • appengine/socket is not required on App Engine flexible environment / Managed VMs. Use the standard net package instead.