Getting Set Up

The Bokeh project encompasses two major components: the Bokeh package source code, written in Python, and the BokehJS client-side library, written in CoffeeScript. Accordingly, development of Bokeh is slightly complicated by the fact that BokehJS requires an explicit compilation step to render the CoffeeScript source into deployable JavaScript.

For this reason, in order to develop Bokeh from a source checkout, you must first be able to build BokehJS.

Cloning the Repository

The source code for the Bokeh project is hosted on GitHub. To clone the source repository, issue the following command:

git clone

This will create a bokeh directory at your location. This bokeh directory is referred to as the “source checkout” for the remainder of this document.

Configuring Git

There are a few configurations you can make locally that will help make working with the repository safer and easier.

Git Hooks

In order to help prevent some accidental situations, here are some git hooks that may be useful. The scripts below should be places in the .git/hooks directory in th top level of the cloned GitHub repository, and be marked executable with e.g. chmod +x pre-commit. For more information on git hooks, see this reference.


This git hook runs the code quality tests before allowing a commit to proceed. Note that all the standard testing dependencies musts be installed in order for this hook to function.


py.test -m quality
exit $?


This git hook prevents accidental pushes to master on GitHub.


current_branch=$(git symbolic-ref HEAD | sed -e 's,.*/\(.*\),\1,')

if [ $protected_branch = $current_branch ]
    read -p "You're about to push master, is that what you intended? [y|n] " -n 1 -r < /dev/tty
    if echo $REPLY | grep -E '^[Yy]$' > /dev/null
        exit 0 # push will execute
    exit 1 # push will not execute
    exit 0 # push will execute

Git Aliases

There are also some useful aliases that can be added to the .gitconfig file located in your home directory.

The following alias adds a git resolve command that will automatically open up your editor to resolve any merge conflicts.

    resolve = !sh -c 'vim -p $(git status -s | grep "^UU" | cut -c4-)'

You can replace vim with whatever your favorite editor command is.

Building BokehJS

The BokehJS build process is handled by Gulp, which in turn depends on Node.js. Gulp is used to compile CoffeeScript and Less (CSS) sources, and to combine these resources into optimized and minified bokeh.js and bokeh.css files.

Install npm and node

First, install Node.js and npm (node package manager). You can download and install these directly, or use conda to install them from the Bokeh channel on

conda install -c bokeh nodejs

Alternatively, on Ubuntu you can use apt-get:

apt-get install npm node

Install Gulp and necessary plugins

Once you have npm and Node.js installed, you must use them to install the required dependencies before you can build BokehJS. Execute the following commands:

cd bokehjs
npm install

This command will install the necessary packages into the node_modules subdirectory (and list them as devDependencies in package.json).

If bokehjs fails, please check if you are working inside the bokehjs directory.

At this point you can typically use the script at the top level of the source checkout to manage building and installing BokehJS as part of the complete Bokeh library (see Python Setup).

However, if you want to work on the BokehJS sources or use BokehJS as a standalone library, then you need to use Gulp to build the BokehJS library as shown below.

Building BokehJS with Gulp

Below are the main Gulp commands for development (to be executed from the bokehjs subdirectory). To run these commands, you can either use bokehjs/node_modules/.bin/gulp, install Gulp globally via npm:

npm install -g gulp

or install gulp via conda (recommended):

conda install -c javascript gulp

To generate the compiled and optimized BokehJS libraries with source maps, and deploy them to the build subdirectory:

gulp build

Additionally, gulp build accepts a --build-dir argument to specify where the built resources should be produced:

gulp build --build-dir=/home/bokeh/mybuilddir

For faster development turnaround, you can skip the very slow minification step of the build by issuing:

gulp dev-build

The non-minified javascript can be used by setting the environment variable BOKEH_MINIFIED=false in the shell.

To direct Gulp to automatically watch the source tree for changes and trigger a recompile if any source file changes:

gulp watch

A Gulp build will automatically generate the sources and their associated source maps. With “source mapping” enabled in your browser, you will be able to:

  • debug the original .coffeescript files when using js/bokeh.js
  • debug the compiled non-minified javascript when using js/bokeh.min.js
  • debug the original .less files when using css/bokeh.css or css/bokeh.min.css

in your developer console.

Python Setup

Once you have a working BokehJS build (which you can verify by completing the steps described in Building BokehJS), you can use the script at the top level of the source checkout to install or develop the full Bokeh library from source.

The script has two main modes of operation: install and develop.

When python install is used, Bokeh will be installed in your local site-packages directory. In this mode, any changes to the python source code will not show up until install is run again.

When python develop is used, a path file bokeh.pth will be written to your site-packages directory that points to the bokeh subdirectory of your source checkout. Any changes to the python source code will be available immediately without any additional steps.

With either mode, you will be prompted for how to install BokehJS, e.g.:

python install

Bokeh includes a JavaScript library (BokehJS) that has its own
build process. How would you like to handle BokehJS:

1) build and install fresh BokehJS
2) install last built BokehJS from bokeh/bokehjs/build


You may skip this prompt by supplying the appropriate command line option to

  • --build-js
  • --install-js

If you have any problems with the steps here, please contact the developers.


In order to build Bokeh from its source, you’ll have to install the project’s python dependencies. If you’re using Conda or pip + virtualenv to setup a development environment, you’ll be able to install these via conda install or pip install for the packages references at Dependencies.

There are additional testing dependencies required to run the unit tests, which include:

  • beautiful-soup
  • colorama
  • pytest
  • pytest-cov
  • pytest-selenium >= 1.0
  • mock
  • websocket-client
  • flake8
  • boto

Both the build and test dependencies can potentially change between releases and be out of sync with the hosted Bokeh site documentation, so the best way to view the current required packages is the review the meta.yaml file included in the Github repository.

In addition to the build and test dependencies, you must also have the base dependencies for Bokeh installed. A simple way to install these dependencies is to install Bokeh via conda install or pip install before running Alternatively, you can download them individually. The dependencies include:

  • jinja2
  • numpy
  • dateutil
  • pyyaml
  • requests
  • tornado

To quickly and easily confirm that your environment contains all of the necessary dependencies to build both the docs and the development version of Bokeh, run the file inside the bokeh/scripts directory.

If any needed packages are missing, you will be given output like this

You are missing the following Dev dependencies:
 *  beautiful-soup

You are missing the following Docs dependencies:
 *  sphinx
 *  pygments

Otherwise, you should see this message

All Dev dependencies installed!  You are good to go!

All Docs dependencies installed!  You are good to go!

Additionally, will check that the bokehjs/node_modules directory exists, which is where npm packages are installed.

If this directory is not found, it will provide instructions on how and where to install npm packages.

Windows Notes

If you build Bokeh on a Windows machine in a Conda environment with either install or develop, running bokeh serve will not work correctly. The .exe will not be available within the Conda environment, which means you will use the version available in the base install, if it is available. Instead, you can make sure you use the Python version within the environment by making use of Python’s -m flag, as in the following example:

python -m bokeh serve path\to\<yourapp>.py

Developing Examples

The processes described so far, discussed solely building BokehJS’ components. When using them in the development repository, you must be cautious about which components are picked by Bokeh, especially when working on examples. Failing to do so, may result in you testing wrong version, specifically CDN version of BokehJS.

In the case of statically generated HTML or IPython notebooks, you should set BOKEH_DEV=true in the shell, e.g.:

BOKEH_DEV=true python

This enables the development mode, which uses absolute paths to development (non-minified) BokehJS components, sets logging to debug, makes generated HTML and JSON human-readable, etc. Alternatively you can enable each part of the development mode with a specific shell variable. For example, to configure Bokeh to use relative paths to development resources, issue:

BOKEH_RESOURCES=relative-dev python

For Bokeh server examples, add BOKEH_DEV=true to the server invocation:

BOKEH_DEV=true bokeh serve

Browser caching

During development, depending on the type of configured resources, aggressive browser caching can sometimes cause new BokehJS code changes to not be picked up. It is recommended that during normal development, browser caching be disabled. Instructions for different browsers can be found here:

Additionally some browsers also provide a “private mode” that may disable caching automatically.

Even with caching disabled, on some browsers, it may still be required to sometimes force a page reload. Keyboard shortcuts for forcing page refreshes can be found here:

If it appears that new changes are not being executed when they should be, it is recommended to try this first.