Setting up a development install#

System requirements#

JupyterHub can only run on MacOS or Linux operating systems. If you are using Windows, we recommend using VirtualBox or a similar system to run Ubuntu Linux for development.

Install Python#

JupyterHub is written in the Python programming language, and requires you have at least version 3.5 installed locally. If you haven’t installed Python before, the recommended way to install it is to use miniconda. Remember to get the ‘Python 3’ version, and not the ‘Python 2’ version!

Install nodejs#

configurable-http-proxy, the default proxy implementation for JupyterHub, is written in Javascript to run on NodeJS. If you have not installed nodejs before, we recommend installing it in the miniconda environment you set up for Python. You can do so with conda install nodejs.

Install git#

JupyterHub uses git & GitHub for development & collaboration. You need to install git to work on JupyterHub. We also recommend getting a free account on

Setting up a development install#

When developing JupyterHub, you need to make changes to the code & see their effects quickly. You need to do a developer install to make that happen.


This guide does not attempt to dictate how development environements should be isolated since that is a personal preference and can be achieved in many ways, for example tox, conda, docker, etc. See this forum thread for a more detailed discussion.

  1. Clone the JupyterHub git repository to your computer.

    git clone
    cd jupyterhub
  2. Make sure the python you installed and the npm you installed are available to you on the command line.

    python -V

    This should return a version number greater than or equal to 3.5.

    npm -v

    This should return a version number greater than or equal to 5.0.

  3. Install configurable-http-proxy. This is required to run JupyterHub.

    npm install -g configurable-http-proxy

    If you get an error that says Error: EACCES: permission denied, you might need to prefix the command with sudo. If you do not have access to sudo, you may instead run the following commands:

    npm install configurable-http-proxy
    export PATH=$PATH:$(pwd)/node_modules/.bin

    The second line needs to be run every time you open a new terminal.

  4. Install the python packages required for JupyterHub development.

    python3 -m pip install -r dev-requirements.txt
    python3 -m pip install -r requirements.txt
  5. Setup a database.

    The default database engine is sqlite so if you are just trying to get up and running quickly for local development that should be available via python. See The Hub’s Database for details on other supported databases.

  6. Install the development version of JupyterHub. This lets you edit JupyterHub code in a text editor & restart the JupyterHub process to see your code changes immediately.

    python3 -m pip install --editable .
  7. You are now ready to start JupyterHub!

  8. You can access JupyterHub from your browser at http://localhost:8000 now.

Happy developing!

Using DummyAuthenticator & SimpleLocalProcessSpawner#

To simplify testing of JupyterHub, it’s helpful to use DummyAuthenticator instead of the default JupyterHub authenticator and SimpleLocalProcessSpawner instead of the default spawner.

There is a sample configuration file that does this in testing/ To launch jupyterhub with this configuration:

jupyterhub -f testing/

The default JupyterHub authenticator & spawner require your system to have user accounts for each user you want to log in to JupyterHub as.

DummyAuthenticator allows you to log in with any username & password, while SimpleLocalProcessSpawner allows you to start servers without having to create a unix user for each JupyterHub user. Together, these make it much easier to test JupyterHub.

Tip: If you are working on parts of JupyterHub that are common to all authenticators & spawners, we recommend using both DummyAuthenticator & SimpleLocalProcessSpawner. If you are working on just authenticator related parts, use only SimpleLocalProcessSpawner. Similarly, if you are working on just spawner related parts, use only DummyAuthenticator.


This section lists common ways setting up your development environment may fail, and how to fix them. Please add to the list if you encounter yet another way it can fail!

lessc not found#

If the python3 -m pip install --editable . command fails and complains about lessc being unavailable, you may need to explicitly install some additional JavaScript dependencies:

npm install

This will fetch client-side JavaScript dependencies necessary to compile CSS.

You may also need to manually update JavaScript and CSS after some development updates, with:

python3 js    # fetch updated client-side js
python3 css   # recompile CSS from LESS sources