Fennel is a lightweight CardDAV / CalDAV server based on node.js




Fennel (c) 2014-15 by SwordLord - the coding crew


Fennel is a lightweight CardDAV / CalDAV server. It is completely written in JavaScript and runs within a Node.js instance. It does have some dependencies regarding JavaScript libraries, but all of these can be installed with the help of the npm.

If you are looking for a lightweight CalDAV / CardDAV, Fennel might be for you:

  • authentication is meant to be pluggable. While we concentrate on CourierAuth, you can add whatever can check a username and password.
  • the data storage backend is meant to be pluggable as well. While we start with SQLite3, we do use an ORM. Whatever database can be used with Sequelize can be used as storage backend for Fennel. You just have to change the setting accordingly.
  • instead of inventing the wheel, we prefer to use some of those fine node.js based libraries.
  • and after all, Fennel is OSS and is written in JavaScript. Whatever you do not like, you are free to replace / rewrite.


Fennel is beta software and should be handled as such:

  • The CalDAV part is mostly done and now ready for a first public beta.
  • The CardDAV part is running and now ready for a first public beta as well.

Fennel is tested on Calendar on iOS > v7.0 and on OSX Calendar as well as with Mozilla Lightning. If you run Fennel with another client your mileage may vary.

What's missing:

  • different clients (we will somewhen test with other clients, but we did not do thoroughly yet)


First of all, you need a Node.js installation.

nodejs on Debian

Make sure that you have this line in your /etc/apt/sources.list file:

deb http://YOURMIRROR.debian.org/debian jessie main

and then run:

sudo apt-get install nodejs nodejs-legacy npm
// eventually the next line as well
// sudo ln -s /usr/lib/nodejs/ /usr/lib/node

nodejs on OSX with homebrew

brew install node
brew install npm

Installation of Fennel

If you want to run Fennel under a specific user (node), do this:

sudo adduser node
su node
mkdir fennel
cd fennel

Go into the directory where you want to run your copy of Fennel and get the latest and greatest:

cd /home/node/fennel
git clone https://github.com/LordEidi/fennel.git

And then with the magic of npm get the required libraries

npm install

If everything worked according to plan, you should now have a new installation of the latest Fennel.

Use supervisord to run Fennel as a service

Now we want to make sure that Fennel runs forever. First install the required software:

sudo apt-get install supervisor

Then copy the file utilities/fennel_supervisor.conf into your local supervisor configuration directory. This is usually done like this:

cp utilities/fennel_supervisor.conf /etc/supervisor/conf.d/fennel.conf 

Make sure you change the configuration to your local setup.

How to set up transport security

Since Fennel does not bring it's own crypto, you may need to install a TLS server in front of Fennel. You can do so with nginx, which is a lightweight http server and proxy.

First prepare your /etc/apt/sources.list file (or just install the standard Debian package, your choice):

deb http://nginx.org/packages/debian/ jessie nginx
deb-src http://nginx.org/packages/debian/ jessie nginx

Update apt-cache and install nginx to your system.

sudo update
sudo apt-get install nginx

Now configure a proxy configuration so that your instance of nginx will serve / prox the content of / for the Fennel server. To do so, you will need a configuration along this example:

server {
    listen   443;
    server_name  carl.yourdomain.tld;

    access_log  /var/www/logs/fennel_access.log combined;
    error_log  /var/www/logs/fennel_error.log;

    root /var/www/pages/;
    index  index.html index.htm;

    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /var/www/nginx-default;

    location / {
        proxy_redirect     off;
        proxy_set_header   Host             $host;
        proxy_set_header   X-Real-IP        $remote_addr;
        proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
        proxy_buffering    off;

    ssl  on;
    ssl_certificate  /etc/nginx/certs/yourdomain.tld.pem;
    ssl_certificate_key  /etc/nginx/certs/yourdomain.tld.pem;
    ssl_session_timeout  5m;

    # modern configuration. tweak to your needs.
    ssl_protocols TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;

    # HSTS (ngx_http_headers_module is required) (15768000 seconds = 6 months)
    add_header Strict-Transport-Security max-age=15768000;

Please check this site for updates on what TLS settings currently make sense:


Now run or reset your nginx and start your instance of Fennel.

Thats it, your instance of Fennel should run now. All logs are sent to stdout for now. Have a look at /libs/log.js if you want to change the options.


All parameters which can be configured right now are in the file config.js. There are not much parameters yet, indeed. But Fennel is not ready production anyway. And you are welcome to help out in adding parameters and configuration options.


The authentication method to use to authenticate users. Supported methods so far:

  • courier: use a local courier authdaemon socket. You will need to fill in this config option as well: auth_method_courier_socket
  • htaccess: use an htaccess file to authenticate the users. You will need to fill in this option as well: auth_method_htaccess_file

How to run

Point your CalDAV and CardDAV client to the root of Fennel. All the rest should be managed by Fennel via ./well-known URLs and the chat between your client and Fennel.


If you happen to know how to write JavaScript, documentation or can help out with something else, drop us a note at contact at swordlord dot com. As more helping hands we have, as quicker this server gets up and feature complete.


For now, have a look at the package.json file.


Fennel is published under the GNU General Public Licence version 3. See the LICENCE file for details.