Polaris Documentation

What is Polaris?

Polaris is a django reusable-app implementing SEP-24 maintained by the Stellar Development Foundation (SDF). SEP-24 is a standard defined to make wallets and anchors interoperable, meaning any wallet can communicate with any anchor for the purpose of withdrawing or depositing assets into the stellar network.

Polaris is not a library or a framework; its an extendable django reusable-app. Like many django apps, it comes with fully-implemented endpoints, templates, and database models. The project is completely open source and available at the SDF’s github.

Polaris does not aim to give you full control of the SEP-24 implementation. Instead, Polaris provides provides developers the ability to integrate with the already-implemented functionality, similar to a framework.

The source code for a functional example of a django project running Polaris can be found under the example folder on github.

Installation and Configuration

First make sure you have cd’ed into your django project’s main directory and then run

pip install django-polaris

Add it to INSTALLED_APPS in settings.py

INSTALLED_APPS = [
    ...,
    "polaris",
]

Add Polaris’ PolarisSameSiteMiddleware to your settings.MIDDLEWARE. Make sure its listed above SessionMiddleware.

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'polaris.middleware.PolarisSameSiteMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

Define PROJECT_ROOT in your project’s settings.py. Polaris uses this to find your .env file.

PROJECT_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

Paste the text below into PROJECT_ROOT/.env.

DJANGO_SECRET_KEY="yoursupersecretkey"
DJANGO_DEBUG=True
STELLAR_DISTRIBUTION_ACCOUNT_SEED=""
STELLAR_ISSUER_ACCOUNT_ADDRESS=""
STELLAR_NETWORK_PASSPHRASE="Test SDF Network ; September 2015"
HORIZON_URI="https://horizon-testnet.stellar.org/"
SERVER_JWT_KEY="yoursupersecretjwtkey"

You’ll need to set up your distribution and issuer accounts on the Stellar network and add them to the file above. Luckily, another engineer at Stellar has built a CLI tool to do this for you.

Add the Polaris endpoints in urls.py

import polaris.urls
from django.urls import path, include

urlpatterns = [
    ...,
    path("", include(polaris.urls)),
]

Run migrations: python manage.py migrate

You now have Polaris completely integrated into your Django project!

Running the Server Locally

Polaris is an HTTPS-only server, so to run it locally you must have a self-signed SSL certificate and configure your browser to trust it.

Run this command to generate a self-signed certificate for localhost:

openssl req -x509 -out localhost.crt -keyout localhost.key \
  -newkey rsa:2048 -nodes -sha256 \
  -subj '/CN=localhost' -extensions EXT -config <( \
   printf "[dn]\nCN=localhost\n[req]\ndistinguished_name = dn\n[EXT]\nsubjectAltName=DNS:localhost\nkeyUsage=digitalSignature\nextendedKeyUsage=serverAuth")

Then, instead of using the usual runserver command, Polaris comes with the runsslserver command. Just add the app to your INSTALLED_APPS:

INSTALLED_APPS = [
    ...,
    "polaris",
    "sslserver"
]

Finally, run these commands in separate windows, or run them all in the background:

python manage.py runsslserver --certificate <path to localhost.crt> --key <path to localhost.key>
python manage.py watch_transactions
python manage.py check_trustlines --loop
python manage.py poll_pending_deposits --loop

The other three processes perform various functions needed to run a fully-functioning anchor, like periodically checking for which pending deposits are ready to be executed on the stellar network.

At this point, you need to start implementing the integration points Polaris provides. Check out the Integrations section for more information.

Contributing

To set up the development environment, fork the repository, then:

cd django-polaris
docker-compose build
docker-compose up

You should now have a minimal anchor server running on port 8000. When you make changes locally, the docker containers will restart with the updated code. Your browser may complain about the service using a self-signed certificate for HTTPS. You can resolve this by marking the certificate used by the service as trusted.

You can install the dependencies locally in a virtual environment:

pip install pipenv
cd django-polaris
pipenv install --dev
pipenv run pytest -c polaris/pytest.ini

Or, you can simply run the tests from inside the docker container. However, this may be slower.

docker exec -it <image ID> pipenv run pytest

After you’ve made your changes, push them to you a remote branch and make a Pull Request on the stellar/django-polaris master branch.