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Google App Engine Boilerplate Build Status

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Google App Engine Boilerplate gets your project off the ground quickly using the Google App Engine platform. Create powerful applications by using the latest technology supported on Google App Engine. It will introduces new developers to App Engine and advanced developers to follow best practices.

Try a online demo

What's a Boilerplate?

A Boilerplate is used to describe sections of code that can be reused over and over in new contexts or applications which provides good default values, reducing the need to specify program details in every project. (wikipedia)

What makes this Boilerplate Amazing?

It is fully featured, actively maintained, and uses the latest and most supported technologies of Google App Engine.

New to Google App Engine? Learn about it by watching this video or reading this website.

Get started in just a few easy steps

  1. Download the last version of the App Engine SDK for Linux, Mac OS or Windows (Tested with SDK version 1.7.2).
  2. Download the code of this Boilerplate (here)
  3. Run locally (instructions).
  4. Set your 'application' name in app.yaml
  5. Set parameters in (secret key, recaptcha code, salt etc.)
  6. Set Authentication Options dropdown to Federated Login in the Google App Engine control panel (or if you do not want federated login, set enable_federated_login to false in
  7. Deploy it online (instructions - recommended setup: python 2.7, high replication datastore)

Functions and features:

  • Authentication (Login, Logout, Sign Up)
  • Federated Login - login via your favorite social network (Google, Twitter, etc...) powered by OpenID and OAuth
  • Reset Password
  • Update User Profile
  • Contact Form
  • Client side and server side form validation
  • Automatic detection of user language
  • Support for 5 Languages (English, Spanish, Italian, Chinese and Indonesian)
  • Visitors Log
  • Notifications and Confirmation for users when they change their email or password
  • Responsive Design for viewing on PCs, tablets, and mobile phones (synchronized with Twitter-Bootstrap project)
  • Mobile identification
  • Unit testing
  • Error handling

Open Source

If you want to add, fix or improve something, create an issue or send a Pull Request.

Before committing fixes we recommend running the unitests. This will help guard against changes that accidently break other code. See the testing section below for instructions.

Feel free to commit improvements or new features. Feedback, comments and ideas are welcome.


Unit testing

  • Unit tests can be run via testrunner or in Eclipse by right clicking on the web folder and selecting run as... Python unit-test.
  • Please add or modify the unittests as necessary.
  • To run unittests it may be necessary to install webtest, mock, and pyquery in your local python installation.
  • Your own unittests can be created similarly to those in the boilerplate. Inheriting from boilerplate.lib.test_helpers.HandlerHelpers will provide access to convenient handler testing methods used by the boilerplate.

Technologies used

  • Python 2.7
  • NDB 1.0.5 (The best datastore API for the Google App Engine Python runtime).
  • Jinja2 2.6 (A fully featured template engine for Python).
  • WTForms-1.0.2 (Forms validation framework keeping user interaction secure and flexible with or without javascript).
  • Babel-0.9.6 and gaepytz-2011h (Industy standard internationalization renders the site in multiple languages).
  • webapp2 2.5.1 (A lightweight Python web framework, the most compatible with Google App Engine).
    • webapp2_extras.sessions
    • webapp2_extras.routes
    • webapp2_extras.auth
    • webapp2_extras.i18n
  • Code written following the Google Python Style Guide
  • Unit testing with unittest, webtest, pyquery
  • OpenID library provided by Google App Engine
  • OAuth2 for federated login providers that do not support OpenID

Front-end Technologies

Please help us translate and add new languages!

In each locale//LC_MESSAGES directory there is a file messages.po. Please help us translate the text in these files. msgid is the text in English. msgstr is the translation to the language indicated by the locale code. For example:

msgid "Change your password"

msgstr "Cambiar tu contraseña"

Working with Internationalization (i18n)

This boilerplate comes bundled with babel, pytz, and automatic language detection which together provide powerful internationalization capability. Text to be translated needs to be indicated in code and then translated by users like you after which it is compiled for speed.

Adding or updating text to be translated or adding new languages requires more work as indicated in the steps below:

  1. Text to be translated should be enclosed in _("text to translate") in *.py files.
    • {{..._("text to translate")...}}
    • {%..._("text to translate")...%}
  2. In html templates translated text is indicated by:

    • {% trans %}text to translate{% endtrans %}

    NOTE: Translations can be added to other types of files too. See babel.cfg and babel.cfg documentation

  3. Obtain pybabel to perform the steps below. You will need to install and compile jinja2 and babel. Note that you may need to first install setuptools and easy_install. pybabel.exe can be run from the Scripts directory in your python installation.
    • easy_install jinja2 babel
  4. Babel then needs to find all translationed text blocks throughout code and templates. After installing pybabl run this command to extract messages (assuming ./ is the location of this boilerplate): pybabel extract -F ./locale/babel.cfg -o ./locale/messages.pot ./ --sort-output --no-location --omit-header
  5. Update translations of existing languages or add new languages
    1. Update translations of existing languages by running this command for each locale: pybabel update -l es_ES -d ./locale -i ./locale/messages.pot --previous --ignore-obsolete Run this command for each locale by replacing es_ES in the command. Locale names are the directory names in ./locale.
    2. Add new languages Run this command for each new language to add. You will need to replace es_ES in the command with the locale code to add. pybabel init -l es_ES -d ./locale -i ./locale\messages.pot Add the locale to the locales array in Instructions on how to pick a locale code are provided in the comments above the array.
  6. Provide translations for each language In each locale//LC_MESSAGES directory there is a file messages.po. Users translate the strings in these files. msgid is the text in English. msgstr is the translation to the language indicated by the locale code. For example:
    • msgid "Change your password"
    • msgstr "Cambiar tu contraseña"
  7. Compile translations Run: pybabel compile -f -d ./locale

See webapp2's tutorial and pybabel's docs for more details.

Disabling i18n i18n can be disabled and language options hidden. Set locales in to None or empty array [] to do this. This may be useful to provide a performance boost or simplify sites that serve a market with only one language. The locale directory can be safely removed to save space if not needed but the babel and pytz directories cannot be removed without breaking code (imports and trans statements) at this time.



  • SSL is enabled site wide by adding secure: always to the section: - url: /.* in app.yaml (remove this line to disable)
  • SSL either requires a free google app engine * domain or a custom domain and certificate
  • Alternatively SSL can be enabled at a controller level via webapp2 schemes. Use the secure_scheme provided in
  • It is recommended to enable ssl site wide to help prevent session hijacking


  • passwords encrypted with SHA512 and PyCrypto



Google App Engine Boilerplate is a collaborative project created by coto which is bringing to you thanks to the help of these amazing people

Top 10: Primary contributors:

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