Radicale v2

Free and Open-Source CalDAV and CardDAV Server

Getting started

About Radicale

Radicale is a small but powerful CalDAV (calendars, todo-lists) and CardDAV (contacts) server, that:

  • Shares calendars through CalDAV, WebDAV and HTTP.
  • Shares contacts through CardDAV, WebDAV and HTTP.
  • Supports events, todos, journal entries and business cards.
  • Works out-of-the-box, no installation nor configuration required.
  • Can warn users on concurrent editing.
  • Can limit access by authentication.
  • Can secure connections.
  • Works with many CalDAV and CardDAV clients.
  • Is GPLv3-licensed free software.


Radicale is really easy to install and works out-of-the-box.

$ python3 -m pip install --upgrade radicale==2.1.*
$ python3 -m radicale --config "" --storage-filesystem-folder=~/.var/lib/radicale/collections

When your server is launched, you can check that everything's OK by going to http://localhost:5232/ with your browser! You can login with any username and password.

Want more? Why don't you check our wonderful documentation?

What's New?

Latest version of Radicale is 2.1.12, released on May 19, 2020 (changelog).

Read latest news…


This documentation page is written for version 2.x.x. If you want to update Radicale from 1.x.x to 2.x.x, please follow our migration guide. You can find on GitHub the documentation page for the 1.1.x versions.

Install and Set Up

You're new to Radicale and you want to know how to use it? Welcome aboard!



Now that you have Radicale running, let's see what we can configure to make it fit your needs.


Using is fun, but hacking is soooooooo coooooool. Radicale is a really small and simple piece of code, it may be the perfect project to start hacking!


You want to try Radicale but only have 5 minutes free in your calendar? Let's go right now! You won't have the best installation ever, but it will be enough to play a little bit with Radicale.

When everything works, you can get a client and start creating calendars and address books. The server only binds to localhost (is not reachable over the network) and you can log in with any user name and password. If Radicale fits your needs, it may be time for some basic configuration.

Follow one of the chapters below depending on your operating system.

Linux / *BSD

First of all, make sure that python 3.3 or later (python ≥ 3.6 is recommended) and pip are installed. On most distributions it should be enough to install the package python3-pip.

Then open a console and type:

# Run the following command as root or
# add the --user argument to only install for the current user
$ python3 -m pip install --upgrade radicale==2.1.*
$ python3 -m radicale --config "" --storage-filesystem-folder=~/.var/lib/radicale/collections

Victory! Open http://localhost:5232/ in your browser! You can login with any username and password.


The first step is to install Python. Go to python.org and download the latest version of Python 3. Then run the installer. On the first window of the installer, check the "Add Python to PATH" box and click on "Install now". Wait a couple of minutes, it's done!

Launch a command prompt and type:

C:\Users\User> python -m pip install --upgrade radicale==2.1.*
C:\Users\User> python -m radicale --config "" --storage-filesystem-folder=~/radicale/collections

If you are using PowerShell replace --config "" with --config '""'.

Victory! Open http://localhost:5232/ in your browser! You can login with any username and password.


To be written.

Basic Setup

Installation instructions can be found on the Tutorial page.


Radicale tries to load configuration files from /etc/radicale/config, ~/.config/radicale/config and the RADICALE_CONFIG environment variable. A custom path can be specified with the --config /path/to/config command line argument.

You should create a new configuration file at the desired location. (If the use of a configuration file is inconvenient, all options can be passed via command line arguments.)

All configuration options are described in detail on the Configuration page.


In its default configuration Radicale doesn't check user names or passwords. If the server is reachable over a network, you should change this.

First a users file with all user names and passwords must be created. It can be stored in the same directory as the configuration file.

The secure way

The users file can be created and managed with htpasswd:

# Create a new htpasswd file with the user "user1"
$ htpasswd -B -c /path/to/users user1
New password:
Re-type new password:
# Add another user
$ htpasswd -B /path/to/users user2
New password:
Re-type new password:

bcrypt is used to secure the passwords. Radicale requires additional dependencies for this encryption method:

$ python3 -m pip install --upgrade radicale[bcrypt]==2.1.*

Authentication can be enabled with the following configuration:

type = htpasswd
htpasswd_filename = /path/to/users
# encryption method used in the htpasswd file
htpasswd_encryption = bcrypt
The simple but insecure way

Create the users file by hand with lines containing the user name and password separated by :. Example:


Authentication can be enabled with the following configuration:

type = htpasswd
htpasswd_filename = /path/to/users
# encryption method used in the htpasswd file
htpasswd_encryption = plain


The default configuration binds the server to localhost. It can't be reached from other computers. This can be changed with the following configuration options:

hosts =

More addresses can be added (separated by commas).


Data is stored in the folder /var/lib/radicale/collections. The path can be changed with the following configuration:

filesystem_folder = /path/to/storage

Security: The storage folder should not be readable by unauthorized users. Otherwise, they can read the calendar data and lock the storage. You can find OS dependent instructions in the Running as a service section.


Radicale enforces limits on the maximum number of parallel connections, the maximum file size (important for contacts with big photos) and the rate of incorrect authentication attempts. Connections are terminated after a timeout. The default values should be fine for most scenarios.

max_connections = 20
# 100 Megabyte
max_content_length = 100000000
# 30 seconds
timeout = 30

# Average delay after failed login attempts in seconds
delay = 1

Running as a service

The method to run Radicale as a service depends on your host operating system. Follow one of the chapters below depending on your operating system and requirements.

Linux with systemd as a user

Create the file ~/.config/systemd/user/radicale.service:

Description=A simple CalDAV (calendar) and CardDAV (contact) server

ExecStart=/usr/bin/env python3 -m radicale


Radicale will load the configuration file from ~/.config/radicale/config. You should set the configuration option filesystem_folder in the storage section to something like ~/.var/lib/radicale/collections.

To enable and manage the service run:

# Enable the service
$ systemctl --user enable radicale
# Start the service
$ systemctl --user start radicale
# Check the status of the service
$ systemctl --user status radicale
# View all log messages
$ journalctl --user --unit radicale.service
Linux with systemd system-wide

Create the radicale user and group for the Radicale service. (Run useradd --system --home-dir / --shell /sbin/nologin radicale as root.) The storage folder must be writable by radicale. (Run mkdir -p /var/lib/radicale/collections && chown -R radicale:radicale /var/lib/radicale/collections as root.)

Security: The storage should not be readable by others. (Run chmod -R o= /var/lib/radicale/collections as root.)

Create the file /etc/systemd/system/radicale.service:

Description=A simple CalDAV (calendar) and CardDAV (contact) server

ExecStart=/usr/bin/env python3 -m radicale
# Deny other users access to the calendar data
# Optional security settings


Radicale will load the configuration file from /etc/radicale/config.

To enable and manage the service run:

# Enable the service
$ systemctl enable radicale
# Start the service
$ systemctl start radicale
# Check the status of the service
$ systemctl status radicale
# View all log messages
$ journalctl --unit radicale.service

MacOS with launchd

To be written.

Classic daemonization

Set the configuration option daemon in the section server to True. You may want to set the option pid to the path of a PID file.

After daemonization the server will not log anything. You have to configure Logging.

If you start Radicale now, it will initialize and fork into the background. The main process exits, after the PID file is written.

Security: You can set the umask with umask 0027 before you start the daemon, to protect your calendar data and log files from other users. Don't forget to set permissions of files that are already created!

Windows with "NSSM - the Non-Sucking Service Manager"

First install NSSM and start nssm install in a command prompt. Apply the following configuration:

  • Service name: Radicale
  • Application
    • Path: C:\Path\To\Python\python.exe
    • Arguments: -m radicale --config C:\Path\To\Config
  • I/O redirection
    • Error: C:\Path\To\Radicale.log

Security: Be aware that the service runs in the local system account, you might want to change this. Managing user accounts is beyond the scope of this manual. Also make sure that the storage folder and log file is not readable by unauthorized users.

The log file might grow very big over time, you can configure file rotation in NSSM to prevent this.

The service is configured to start automatically when the computer starts. To start the service manually open Services in Computer Management and start the Radicale service.

Reverse Proxy

When a reverse proxy is used, the path at which Radicale is available must be provided via the X-Script-Name header. The proxy must remove the location from the URL path that is forwarded to Radicale.

Example nginx configuration:

location /radicale/ { # The trailing / is important!
    proxy_pass        http://localhost:5232/; # The / is important!
    proxy_set_header  X-Script-Name /radicale;
    proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_pass_header Authorization;

Example Apache configuration:

RewriteEngine On
RewriteRule ^/radicale$ /radicale/ [R,L]

<Location "/radicale/">
    ProxyPass        http://localhost:5232/ retry=0
    ProxyPassReverse http://localhost:5232/
    RequestHeader    set X-Script-Name /radicale/

Be reminded that Radicale's default configuration enforces limits on the maximum number of parallel connections, the maximum file size and the rate of incorrect authentication attempts. Connections are terminated after a timeout.

Manage user accounts with the reverse proxy

Set the configuration option type in the auth section to http_x_remote_user. Radicale uses the user name provided in the X-Remote-User HTTP header and disables HTTP authentication.

Example nginx configuration:

location /radicale/ {
    proxy_pass           http://localhost:5232/;
    proxy_set_header     X-Script-Name /radicale;
    proxy_set_header     X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header     X-Remote-User $remote_user;
    auth_basic           "Radicale - Password Required";
    auth_basic_user_file /etc/nginx/htpasswd;

Example Apache configuration:

RewriteEngine On
RewriteRule ^/radicale$ /radicale/ [R,L]

<Location "/radicale/">
    AuthType      Basic
    AuthName      "Radicale - Password Required"
    AuthUserFile  "/etc/radicale/htpasswd"
    Require       valid-user

    ProxyPass        http://localhost:5232/ retry=0
    ProxyPassReverse http://localhost:5232/
    RequestHeader    set X-Script-Name /radicale/
    RequestHeader    set X-Remote-User expr=%{REMOTE_USER}

Security: Untrusted clients should not be able to access the Radicale server directly. Otherwise, they can authenticate as any user.

Secure connection between Radicale and the reverse proxy

SSL certificates can be used to encrypt and authenticate the connection between Radicale and the reverse proxy. First you have to generate a certificate for Radicale and a certificate for the reverse proxy. The following commands generate self-signed certificates. You will be asked to enter additional information about the certificate, the values don't matter and you can keep the defaults.

$ openssl req -x509 -newkey rsa:4096 -keyout server_key.pem -out server_cert.pem -nodes -days 9999
$ openssl req -x509 -newkey rsa:4096 -keyout client_key.pem -out client_cert.pem -nodes -days 9999

Use the following configuration for Radicale:

ssl = True
certificate = /path/to/server_cert.pem
key = /path/to/server_key.pem
certificate_authority = /path/to/client_cert.pem

Example nginx configuration:

location /radicale/ {
    proxy_pass https://localhost:5232/;
    # Place the files somewhere nginx is allowed to access (e.g. /etc/nginx/...).
    proxy_ssl_certificate         /path/to/client_cert.pem;
    proxy_ssl_certificate_key     /path/to/client_key.pem;
    proxy_ssl_trusted_certificate /path/to/server_cert.pem;


Radicale is compatible with the WSGI specification.

A configuration file can be set with the RADICALE_CONFIG environment variable, otherwise no configuration file is loaded and the default configuration is used.

Be reminded that Radicale's default configuration enforces limits on the maximum upload file size.

Security: The None authentication type disables all rights checking. Don't use it with REMOTE_USER. Use remote_user instead.

Example uWSGI configuration:

http-socket =
processes = 8
plugin = python3
module = radicale
env = RADICALE_CONFIG=/etc/radicale/config

Example Gunicorn configuration:

gunicorn --bind '' --workers 8 --env 'RADICALE_CONFIG=/etc/radicale/config' radicale

Manage user accounts with the WSGI server

Set the configuration option type in the auth section to remote_user. Radicale uses the user name provided by the WSGI server and disables authentication over HTTP.


This page describes how to keep track of all changes to calendars and address books with git (or any other version control system).

The repository must be initialized by running git init in the file system folder. Internal files of Radicale can be excluded by creating the file .gitignore with the following content:


The configuration option hook in the storage section must be set to the following command:

git add -A && (git diff --cached --quiet || git commit -m "Changes by "%(user)s)

The command gets executed after every change to the storage and commits the changes into the git repository.


Radicale has been tested with:

Many clients do not support the creation of new calendars and address books. You can use Radicale's web interface (e.g. http://localhost:5232) to create and manage collections.

In some clients you can just enter the URL of the Radicale server (e.g. http://localhost:5232) and your user name. In others, you have to enter the URL of the collection directly (e.g. http://localhost:5232/user/calendar).


Enter the URL of the Radicale server (e.g. http://localhost:5232) and your user name. DAVx⁵ will show all existing calendars and address books and you can create new.

GNOME Calendar, Contacts and Evolution

GNOME Calendar and Contacts do not support adding WebDAV calendars and address books directly, but you can add them in Evolution.

In Evolution add a new calendar and address book respectively with WebDAV. Enter the URL of the Radicale server (e.g. http://localhost:5232) and your user name. Clicking on the search button will list the existing calendars and address books.



Add a new address book on the network with CardDAV. You have to enter the full URL of the collection (e.g. http://localhost:5232/user/addressbook) and your user name.


Add a new calendar on the network with CalDAV. (Don't use iCalendar (ICS)!) You have to enter the full URL of the collection (e.g. http://localhost:5232/user/calendar). If you want to add calendars from different users on the same server, you can specify the user name in the URL (e.g. http://user@localhost...)

InfCloud, CalDavZAP and CardDavMATE

You can integrate InfCloud into Radicale's web interface with RadicaleInfCloud. No additional configuration is required.

Set the URL of the Radicale server in config.js. If InfCloud is not hosted on the same server and port as Radicale, the browser will deny access to the Radicale server, because of the same-origin policy. You have to add additional HTTP header in the headers section of Radicale's configuration. The documentation of InfCloud has more details on this.

Manual creation of calendars and address books

This is not the recommended way of creating and managing your calendars and address books. Use Radicale's web interface or a client with support for it (e.g. DAVx⁵).

Direct editing of the storage

To create a new collection, you have to create the corresponding folder in the file system storage (e.g. collection-root/user/calendar). To tell Radicale and clients that the collection is a calendar, you have to create the file .Radicale.props with the following content in the folder:

{"tag": "VCALENDAR"}

The calendar is now available at the URL path /user/calendar. For address books the file must contain:


Calendar and address book collections must not have any child collections. Clients with automatic discovery of collections will only show calendars and addressbooks that are direct children of the path /USERNAME/.

Delete collections by deleting the corresponding folders.

HTTP requests with curl

To create a new calendar run something like:

$ curl -u user -X MKCOL 'http://localhost:5232/user/calendar' --data \
'<?xml version="1.0" encoding="UTF-8" ?>
<create xmlns="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav" xmlns:I="http://apple.com/ns/ical/">
        <collection />
        <C:calendar />
        <C:comp name="VEVENT" />
        <C:comp name="VJOURNAL" />
        <C:comp name="VTODO" />
      <C:calendar-description>Example calendar</C:calendar-description>

To create a new address book run something like:

$ curl -u user -X MKCOL 'http://localhost:5232/user/addressbook' --data \
'<?xml version="1.0" encoding="UTF-8" ?>
<create xmlns="DAV:" xmlns:CR="urn:ietf:params:xml:ns:carddav">
        <collection />
        <CR:addressbook />
      <displayname>Address book</displayname>
      <CR:addressbook-description>Example address book</CR:addressbook-description>

The collection /USERNAME will be created automatically, when the user authenticates to Radicale for the first time. Clients with automatic discovery of collections will only show calendars and address books that are direct children of the path /USERNAME/.

Delete the collections by running something like:

$ curl -u user -X DELETE 'http://localhost:5232/user/calendar'


Radicale can be configured with a configuration file or with command line arguments.

An example configuration file looks like:

# Bind all addresses
hosts =

type = htpasswd
htpasswd_filename = /path/to/users
htpasswd_encryption = bcrypt
filesystem_folder = ~/.var/lib/radicale/collections

Radicale tries to load configuration files from /etc/radicale/config, ~/.config/radicale/config and the RADICALE_CONFIG environment variable. This behaviour can be overwritten by specifying a path with the --config /path/to/config command line argument.

The same example configuration via command line arguments looks like:

python3 -m radicale --config "" --server-hosts --auth-type htpasswd --htpasswd-filename /path/to/htpasswd --htpasswd-encryption bcrypt

The --config "" argument is required to stop Radicale from trying to load configuration files. Run python3 -m radicale --help for more information.

In the following, all configuration categories and options are described.


Most configuration options in this category are only relevant in standalone mode. All options beside max_content_length and realm are ignored, when Radicale runs via WSGI.


A comma separated list of addresses that the server will bind to.



Daemonize the Radicale process. It does not reset the umask.

Default: False


If daemon mode is enabled, Radicale will write its PID to this file.



The maximum number of parallel connections. Set to 0 to disable the limit.

Default: 20


The maximum size of the request body. (bytes)

Default: 100000000


Socket timeout. (seconds)

Default: 30


Enable transport layer encryption.

Default: False


Path of the SSL certifcate.

Default: /etc/ssl/radicale.cert.pem


Path to the private key for SSL. Only effective if ssl is enabled.

Default: /etc/ssl/radicale.key.pem


Path to the CA certificate for validating client certificates. This can be used to secure TCP traffic between Radicale and a reverse proxy. If you want to authenticate users with client-side certificates, you also have to write an authentication plugin that extracts the user name from the certifcate.



SSL protocol used. See python's ssl module for available values.

Default: PROTOCOL_TLSv1_2


Available ciphers for SSL. See python's ssl module for available ciphers.



Reverse DNS to resolve client address in logs.

Default: True


Message displayed in the client when a password is needed.

Default: Radicale - Password Required



Encoding for responding requests.

Default: utf-8


Encoding for storing local collections

Default: utf-8



The method to verify usernames and passwords.

Available backends:

None : Just allows all usernames and passwords. It also disables rights checking.

htpasswd : Use an Apache htpasswd file to store usernames and passwords.

remote_user : Takes the user name from the REMOTE_USER environment variable and disables HTTP authentication. This can be used to provide the user name from a WSGI server.

http_x_remote_user : Takes the user name from the X-Remote-User HTTP header and disables HTTP authentication. This can be used to provide the user name from a reverse proxy.

Default: None


Path to the htpasswd file.



The encryption method that is used in the htpasswd file. Use the htpasswd or similar to generate this files.

Available methods:

plain : Passwords are stored in plaintext. This is obviously not secure! The htpasswd file for this can be created by hand and looks like:


bcrypt : This uses a modified version of the Blowfish stream cipher. It's very secure. The passlib python module is required for this. Additionally you may need one of the following python modules: bcrypt, py-bcrypt or bcryptor.

md5 : This uses an iterated md5 digest of the password with a salt. The passlib python module is required for this.

sha1 : Passwords are stored as SHA1 hashes. It's insecure!

ssha : Passwords are stored as salted SHA1 hashes. It's insecure!

crypt : This uses UNIX crypt(3). It's insecure!

Default: bcrypt


Average delay after failed login attempts in seconds.

Default: 1



The backend that is used to check the access rights of collections.

The recommended backend is owner_only. If access to calendars and address books outside of the home directory of users (that's /USERNAME/) is granted, clients won't detect these collections and will not show them to the user. Choosing any other method is only useful if you access calendars and address books directly via URL.

Available backends:

None : Everyone can read and write everything.

authenticated : Authenticated users can read and write everything.

owner_only : Authenticated users can read and write their own collections under the path /USERNAME/.

owner_write : Authenticated users can read everything and write their own collections under the path /USERNAME/.

from_file : Load the rules from a file.

Default: owner_only


File for the rights backend from_file. See the Rights page.



The backend that is used to store data.

Available backends:

multifilesystem : Stores the data in the filesystem.

Default: multifilesystem


Folder for storing local collections, created if not present.

Default: /var/lib/radicale/collections


Lock the storage. This must be disabled if locking is not supported by the underlying file system. Never start multiple instances of Radicale or edit the storage externally while Radicale is running if disabled.

Default: True


Delete sync-token that are older than the specified time. (seconds)

Default: 2592000


Sync all changes to disk during requests. (This can impair performance.) Disabling it increases the risk of data loss, when the system crashes or power fails!

Default: True


Command that is run after changes to storage. Take a look at the Versioning page for an example.




The backend that provides the web interface of Radicale.

Available backends:

none : Just shows the message "Radicale works!".

internal : Allows creation and management of address books and calendars.

Default: internal



Set the default logging level to debug.

Default: False


Log all environment variables (including those set in the shell).

Default: False


Don't include passwords in logs.

Default: True


Logging configuration file. See the Logging page.



In this section additional HTTP headers that are sent to clients can be specified.

An example to relax the same-origin policy:

Access-Control-Allow-Origin = *

Authentication and Rights

This page describes the format of the rights file for the from_file authentication backend. The configuration option file in the rights section must point to the rights file.

The recommended rights method is owner_only. If access to calendars and address books outside of the home directory of users (that's /USERNAME/) is granted, clients won't detect these collections and will not show them to the user. This is only useful if you access calendars and address books directly via URL.

An example rights file:

# The user "admin" can read and write any collection.
user = admin
collection = .*
permission = rw

# Block access for the user "user" to everything.
user = user
collection = .*
permission =

# Authenticated users can read and write their own collections.
user = .+
collection = %(login)s(/.*)?
permission = rw

# Everyone can read the root collection
user = .*
collection =
permission = r

The titles of the sections are ignored (but must be unique). The keys user and collection contain regular expressions, that are matched against the user name and the path of the collection. Permissions from the first matching section are used. If no section matches, access gets denied.

The user name is empty for anonymous users. Therefore, the regex .+ only matches authenticated users and .* matches everyone (including anonymous users).

The path of the collection is separated by / and has no leading or trailing /. Therefore, the path of the root collection is empty.

%(login)s gets replaced by the user name and %(path)s by the path of the collection. You can also get groups from the user regex in the collection regex with {0}, {1}, etc.


This document describes the layout and format of the file system storage (multifilesystem backend).

It's safe to access and manipulate the data by hand or with scripts. Scripts can be invoked manually, periodically (e.g. with cron) or after each change to the storage with the configuration option hook in the storage section (e.g. Git Versioning).


The file system contains the following files and folders:

  • .Radicale.lock: The lock file for locking the storage.
  • collection-root: This folder contains all collections and items.

A collection is represented by a folder. This folder may contain the file .Radicale.props with all WebDAV properties of the collection encoded as JSON.

An item is represented by a file containing the iCalendar data.

All files and folders, whose names start with a dot but not .Radicale. (internal files) are ignored.

If you introduce syntax errors in any of the files, all requests that access the faulty data will fail. The logging output should contain the names of the culprits.

Future releases of Radicale 2.x.x will store caches and sync-tokens in the .Radicale.cache folder inside of collections. This folder may be created or modified, while the storage is locked for shared access. In theory, it should be safe to delete the folder. Caches will be recreated automatically and clients will be told that their sync-token isn't valid anymore.

You may encounter files or folders that start with .Radicale.tmp-. Radicale uses them for atomic creation and deletion of files and folders. They should be deleted after requests are finished but it's possible that they are left behind when Radicale or the computer crashes. It's safe to delete them.


When the data is accessed by hand or by an externally invoked script, the storage must be locked. The storage can be locked for exclusive or shared access. It prevents Radicale from reading or writing the file system. The storage is locked with exclusive access while the hook runs.

Linux shell scripts

Use the flock utility.

# Exclusive
$ flock --exclusive /path/to/storage/.Radicale.lock COMMAND
# Shared
$ flock --shared /path/to/storage/.Radicale.lock COMMAND
Linux and MacOS

Use the flock syscall. Python provides it in the fcntl module.


Use LockFile for exclusive access or LockFileEx which also supports shared access. Setting nNumberOfBytesToLockLow to 1 and nNumberOfBytesToLockHigh to 0 works.


Radicale logs to stderr. The verbosity of the log output can be controlled with --debug command line argument or the debug configuration option in the logging section.

This is the recommended configuration for use with modern init systems (like systemd) or if you just test Radicale in a terminal.

You can configure Radicale to write its logging output to files (and even rotate them). This is useful if the process daemonizes or if your chosen method of running Radicale doesn't handle logging output.

A logging configuration file can be specified in the config configuration option in the logging section. The file format is explained in the Python Logging Module.

Logging to a file

An example configuration to write the log output to the file /var/log/radicale/log:

keys = root

keys = file

keys = full

# Change this to DEBUG or INFO for higher verbosity.
level = WARNING
handlers = file

class = FileHandler
# Specify the output file here.
args = ('/var/log/radicale/log',)
formatter = full

format = %(asctime)s - [%(thread)x] %(levelname)s: %(message)s

You can specify multiple logger, handler and formatter if you want to have multiple simultaneous log outputs.

The parent folder of the log files must exist and must be writable by Radicale.

Security: The log files should not be readable by unauthorized users. Set permissions accordingly.

Timed rotation of disk log files

An example handler configuration to write the log output to the file /var/log/radicale/log and rotate it. Replace the section handler_file from the file logging example:

class = handlers.TimedRotatingFileHandler
# Specify the output file and parameter for rotation here.
# See https://docs.python.org/3/library/logging.handlers.html#logging.handlers.TimedRotatingFileHandler
# Example: rollover at midnight and keep 7 files (means one week)
args = ('/var/log/radicale/log', 'midnight', 1, 7)
formatter = full
Rotation of disk log files based on size

An example handler configuration to write the log output to the file /var/log/radicale/log and rotate it . Replace the section handle_file from the file logging example:

class = handlers.RotatingFileHandler
# Specify the output file and parameter for rotation here.
# See https://docs.python.org/3/library/logging.handlers.html#logging.handlers.RotatingFileHandler
# Example: rollover at 100000 kB and keep 10 files (means 1 MB)
args = ('/var/log/radicale/log', 'a', 100000, 10)
formatter = full


Radicale is a really small piece of software, but understanding it is not as easy as it seems. But don't worry, reading this short page is enough to understand what a CalDAV/CardDAV server is, and how Radicale's code is organized.

General Architecture

Here is a simple overview of the global architecture for reaching a calendar or an address book through network:

Part Layer Protocol or Format
Server Calendar/Contact Storage iCal/vCard
Calendar/Contact Server CalDAV/CardDAV Server
Transfer Network CalDAV/CardDAV (HTTP + TLS)
Client Calendar/Contact Client CalDAV/CardDAV Client
GUI Terminal, GTK, Web interface, etc.

Radicale is only the server part of this architecture.

Please note that:

  • CalDAV and CardDAV are superset protocols of WebDAV,
  • WebDAV is a superset protocol of HTTP.

Radicale being a CalDAV/CardDAV server, it also can be seen as a special WebDAV and HTTP server.

Radicale is not the client part of this architecture. It means that Radicale never draws calendars, address books, events and contacts on the screen. It only stores them and give the possibility to share them online with other people.

If you want to see or edit your events and your contacts, you have to use another software called a client, that can be a "normal" applications with icons and buttons, a terminal or another web application.

Code Architecture

The radicale package offers 9 modules.

__main__ : The main module provides a simple function called run. Its main work is to read the configuration from the configuration file and from the options given in the command line; then it creates a server, according to the configuration.

__init__ : This is the core part of the module, with the code for the CalDAV/CardDAV server. The server inherits from a WSGIServer server class, which relies on the default HTTP server class given by Python. The code managing the different HTTP requests according to the CalDAV/CardDAV normalization is written here.

config : This part gives a dict-like access to the server configuration, read from the configuration file. The configuration can be altered when launching the executable with some command line options.

xmlutils : The functions defined in this module are mainly called by the CalDAV/CardDAV server class to read the XML part of the request, read or alter the calendars, and create the XML part of the response. The main part of this code relies on ElementTree.

log : The start function provided by this module starts a logging mechanism based on the default Python logging module. Logging options can be stored in a logging configuration file.

auth : This module provides a default authentication manager equivalent to Apache's htpasswd. Login + password couples are stored in a file and used to authenticate users. Passwords can be encrypted using various methods. Other authentication methods can inherit from the base class in this file and be provided as plugins.

rights : This module is a set of Access Control Lists, a set of methods used by Radicale to manage rights to access the calendars. When the CalDAV/CardDAV server is launched, an Access Control List is chosen in the set, according to the configuration. The HTTP requests are then filtered to restrict the access depending on who is authenticated. Other configurations can be written using regex-based rules. Other rights managers can also inherit from the base class in this file and be provided as plugins.

storage : In this module are written the classes representing collections and items in Radicale, and the class storing these collections and items in your filesystem. Other storage classes can inherit from the base class in this file and be provided as plugins.

web : This module contains the web interface.


Radicale can be extended by plugins for authentication, rights management and storage. Plugins are python modules.

Getting started

To get started we walk through the creation of a simple authentication plugin, that accepts login attempts if the username and password are equal.

The easiest way to develop and install python modules is Distutils. For a minimal setup create the file setup.py with the following content in an empty folder:

#!/usr/bin/env python3

from distutils.core import setup

setup(name="radicale_silly_auth", packages=["radicale_silly_auth"])

In the same folder create the sub-folder radicale_silly_auth. The folder must have the same name as specified in packages above.

Create the file __init__.py in the radicale_silly_auth folder with the following content:

from radicale.auth import BaseAuth

class Auth(BaseAuth):
    def is_authenticated(self, user, password):
        # Example custom configuration option
        foo = ""
        if self.configuration.has_option("auth", "foo"):
            foo = self.configuration.get("auth", "foo")
        self.logger.info("Configuration option %r is %r", "foo", foo)

        # Check authentication
        self.logger.info("Login attempt by %r with password %r",
                         user, password)
        return user == password

Install the python module by running the following command in the same folder as setup.py:

python3 -m pip install --upgrade .

To make use this great creation in Radicale, set the configuration option type in the auth section to radicale_silly_auth:

type = radicale_silly_auth
foo = bar

You can uninstall the module with:

python3 -m pip uninstall radicale_silly_auth

Authentication plugins

This plugin type is used to check login credentials. The module must contain a class Auth that extends radicale.auth.BaseAuth. Take a look at the file radicale/auth.py in Radicale's source code for more information.

Rights management plugins

This plugin type is used to check if a user has access to a path. The module must contain a class Rights that extends radicale.rights.BaseRights. Take a look at the file radicale/rights.py in Radicale's source code for more information.

Web plugins

This plugin type is used to provide the web interface for Radicale. The module must contain a class Web that extends radicale.web.BaseWeb. Take a look at the file radicale/web.py in Radicale's source code for more information.

Storage plugins

This plugin is used to store collections and items. The module must contain a class Collection that extends radicale.storage.BaseCollection. Take a look at the file radicale/storage.py in Radicale's source code for more information.

Migration from 1.x.x to 2.x.x

Why a Migration?

Radicale 2.x.x is different from 1.x.x, here's everything you need to know about this! Please read this page carefully if you want to update Radicale.

You'll also find extra information in issue #372.

Python 3 Only

Radicale 2.x.x works with Python >= 3.3, and doesn't work anymore with Python 2.

(No, Python 3.3 is not new, it's been released more than 4 years ago. Debian stable provides Python 3.4.)


Radicale now depends on VObject, a "full-featured Python package for parsing and creating iCalendar and vCard files". That's the price to pay to correctly read crazy iCalendar files and support date-based filters, even on recurring events.


Calendars and address books are stored in a different way between 1.x.x and 2.x.x versions. Launching 2.x.x without migrating your collections first will not work, Radicale won't be able to read your previous data.

There's now only one way to store data in Radicale: collections are stored as folders and events / contacts are stored in files. This new storage is close to the multifilesystem, but it's now thread-safe, with atomic writes and file locks. Other storage types can be used by creating plugins.

To migrate data to Radicale 2.x.x the command line argument --export-storage was added to Radicale 1.1.x. Start Radicale 1.x.x as you would normally do, but add the argument --export-storage path/to/empty/folder. Radicale will export the storage into the specified folder. This folder can be directly used with the default storage backend of Radicale 2.x.x.

If you import big calendars or address books into Radicale 2.x.x the first request might take a long time, because it has to initialize its internal caches. Clients can time out, subsequent requests will be much faster.

You can check the imported storage for errors by starting Radicale >= 2.1.5 with the --verify-storage argument.

You can install version 1.1.x with:

$ python3 -m pip install --upgrade radicale==1.1.*


Radicale 2.x.x only provides htpasswd authentication out-of-the-box. Other authentication methods can be added by creating or using plugins.


In Radicale 2.x.x, rights are managed using regex-based rules based on the login of the authenticated user and the URL of the resource. Default configurations are built in for common cases, you'll find more about this on the Authentication & Rights page.

Other rights managers can be added by creating plugins.


Support for versioning with git was removed from Radicale 2.x.x. Instead, the configuration option hook in the storage section was added, the Collection Versioning page explains its usage for version control.


Chat with Us on IRC

Want to say something? Join our IRC room: ##kozea on Freenode.

Report Bugs

Found a bug? Want a new feature? Report a new issue on the Radicale bug-tracker.


Interested in hacking? Feel free to clone the git repository on Github if you want to add new features, fix bugs or update the documentation.


To change or complement the documentation create a pull request to DOCUMENTATION.md.



Radicale is available on PyPI. To install, just type as superuser:

$ python3 -m pip install --upgrade radicale==2.1.*

Git Repository

If you want the development version of Radicale, take a look at the git repository on GitHub, or install it directly with:

$ python3 -m pip install --upgrade git+https://github.com/Kozea/Radicale

You can also download the content of the repository as an archive.

Source Packages

You can download the Radicale package for each release:

Linux Distribution Packages

Radicale has been packaged for:

Radicale is also available on Cloudron and has a Dockerfile.

If you are interested in creating packages for other Linux distributions, read the "Contribute" page.


Main Goals

Radicale is a complete calendar and contact storing and manipulating solution. It can store multiple calendars and multiple address books.

Calendar and contact manipulation is available from both local and distant accesses, possibly limited through authentication policies.

It aims to be a lightweight solution, easy to use, easy to install, easy to configure. As a consequence, it requires few software dependencies and is pre-configured to work out-of-the-box.

Radicale is written in Python. It runs on most of the UNIX-like platforms (Linux, *BSD, macOS) and Windows. It is free and open-source software.

What Radicale Will Never Be

Radicale is a server, not a client. No interfaces will be created to work with the server, as it is a really (really really) much more difficult task.

CalDAV and CardDAV are not perfect protocols. We think that their main problem is their complexity, that is why we decided not to implement the whole standard but just enough to understand some of its client-side implementations.

CalDAV and CardDAV are the best open standards available and they are quite widely used by both clients and servers. We decided to use it, and we will not use another one.

Technical Choices

Important global development choices have been decided before writing code. They are very useful to understand why the Radicale Project is different from other CalDAV and CardDAV servers, and why features are included or not in the code.

Oriented to Calendar and Contact User Agents

Calendar and contact servers work with calendar and contact clients, using a defined protocol. CalDAV and CardDAV are good protocols, covering lots of features and use cases, but it is quite hard to implement fully.

Some calendar servers have been created to follow the CalDAV and CardDAV RFCs as much as possible: Davical, Baïkal and Darwin Calendar Server, for example, are much more respectful of CalDAV and CardDAV and can be used with a large number of clients. They are very good choices if you want to develop and test new CalDAV clients, or if you have a possibly heterogeneous list of user agents.

Even if it tries it best to follow the RFCs, Radicale does not and will not blindly implements the CalDAV and CardDAV standards. It is mainly designed to support the CalDAV and CardDAV implementations of different clients.


Radicale is designed to be simple to install, simple to configure, simple to use.

The installation is very easy, particularly with Linux: one dependency, no superuser rights needed, no configuration required, no database. Installing and launching the main script out-of-the-box, as a normal user, are often the only steps to have a simple remote calendar and contact access.

Contrary to other servers that are often complicated, require high privileges or need a strong configuration, the Radicale Server can (sometimes, if not often) be launched in a couple of minutes, if you follow the tutorial.


The CalDAV RFC defines what must be done, what can be done and what cannot be done. Many violations of the protocol are totally defined and behaviours are given in such cases.

Radicale often assumes that the clients are perfect and that protocol violations do not exist. That is why most of the errors in client requests have undetermined consequences for the lazy server that can reply good answers, bad answers, or even no answer.


Radicale has been started as a (free topic) stupid school project replacing another (assigned topic) even more stupid school project.

At the beginning, it was just a proof-of-concept. The main goal was to write a small, dirty and simple CalDAV server working with Lightning, using no external libraries. That's how we created a piece of code that's (quite) easy to understand, to use and to hack.

The first lines have been added to the SVN (!) repository as I was drinking (many) beers at the very end of 2008 (Python 2.6 and 3.0 were just released). It's now packaged for a growing number of Linux distributions.

And that was fun going from here to there thanks to you!


Latest version of Radicale is 2.1.12, released on May 19, 2020 (changelog).

May 19, 2020 - Radicale 2.1.12

Radicale 2.1.12 is out!

2.1.12 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Include documentation in source archive

November 5, 2018 - Radicale 2.1.11

Radicale 2.1.11 is out!

2.1.11 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Fix moving items between collections

August 16, 2018 - Radicale 2.1.10

Radicale 2.1.10 is out!

2.1.10 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Update required versions for dependencies
  • Get RADICALE_CONFIG from WSGI environ
  • Improve HTTP status codes
  • Fix race condition in storage lock creation
  • Raise default limits for content length and timeout
  • Log output from hook

April 21, 2018 - Radicale 2.1.9

Radicale 2.1.9 is out!

2.1.9 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Specify versions for dependencies
  • Move WSGI initialization into module
  • Check if REPORT method is actually supported
  • Include rights file in source distribution
  • Specify md5 and bcrypt as extras
  • Improve logging messages
  • Windows: Fix crash when item path is a directory

September 24, 2017 - Radicale 2.1.8

Radicale 2.1.8 is out!

2.1.8 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Flush files before fsync'ing

September 17, 2017 - Radicale 2.1.7

Radicale 2.1.7 is out!

2.1.7 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Don't print warning when cache format changes
  • Add documentation for BaseAuth
  • Add is_authenticated2(login, user, password) to BaseAuth
  • Fix names of custom properties in PROPFIND requests with D:propname or D:allprop
  • Return all properties in PROPFIND requests with D:propname or D:allprop
  • Allow D:displayname property on all collections
  • Answer with D:unauthenticated for D:current-user-principal property when not logged in
  • Remove non-existing ICAL:calendar-color and C:calendar-timezone properties from PROPFIND requests with D:propname or D:allprop
  • Add D:owner property to calendar and address book objects
  • Remove D:getetag and D:getlastmodified properties from regular collections

September 11, 2017 - Radicale 2.1.6

Radicale 2.1.6 is out!

2.1.6 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Fix content-type of VLIST
  • Specify correct COMPONENT in content-type of VCALENDAR
  • Cache COMPONENT of calendar objects (improves speed with some clients)
  • Stricter parsing of filters
  • Improve support for CardDAV filter
  • Fix some smaller bugs in CalDAV filter
  • Add X-WR-CALNAME and X-WR-CALDESC to calendars downloaded via HTTP/WebDAV
  • Use X-WR-CALNAME and X-WR-CALDESC from calendars published via WebDAV

August 25, 2017 - Radicale 2.1.5

Radicale 2.1.5 is out!

2.1.5 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Add --verify-storage command-line argument
  • Allow comments in the htpasswd file
  • Don't strip whitespaces from user names and passwords in the htpasswd file
  • Remove cookies from logging output
  • Allow uploads of whole collections with many components
  • Show warning message if server.timeout is used with Python < 3.5.2

August 4, 2017 - Radicale 2.1.4

Radicale 2.1.4 is out!

2.1.4 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Fix incorrect time range matching and calculation for some edge-cases with rescheduled recurrences
  • Fix owner property

August 2, 2017 - Radicale 2.1.3

Radicale 2.1.3 is out!

2.1.3 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Enable timeout for SSL handshakes and move them out of the main thread
  • Create cache entries during upload of items
  • Stop built-in server on Windows when Ctrl+C is pressed
  • Prevent slow down when multiple requests hit a collection during cache warm-up

July 24, 2017 - Radicale 2.1.2

Radicale 2.1.2 is out!

2.1.2 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Remove workarounds for bugs in VObject < 0.9.5
  • Error checking of collection tags and associated components
  • Improve error checking of uploaded collections and components
  • Don't delete empty collection properties implicitly
  • Improve logging of VObject serialization

July 1, 2017 - Radicale 2.1.1

Radicale 2.1.1 is out!

2.1.1 - Wild Radish Again

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.x.x.

  • Add missing UIDs instead of failing
  • Improve error checking of calendar and address book objects
  • Fix upload of whole address books

June 25, 2017 - Radicale 2.1.0

Radicale 2.1.0 is out!

2.1.0 - Wild Radish

This release is compatible with version 2.0.0. Follow our migration guide if you want to switch from 1.x.x to 2.1.0.

  • Built-in web interface for creating and managing address books and calendars
    • can be extended with web plugins
  • Much faster storage backend
  • Significant reduction in memory usage
  • Improved logging
    • Include paths (of invalid items / requests) in log messages
    • Include configuration values causing problems in log messages
    • Log warning message for invalid requests by clients
    • Log error message for invalid files in the storage backend
    • No stack traces unless debugging is enabled
  • Time range filter also regards overwritten recurrences
  • Items that couldn't be filtered because of bugs in VObject are always returned (and a warning message is logged)
  • Basic error checking of configuration files
  • File system locking isn't disabled implicitly anymore, instead a new configuration option gets introduced
  • The permissions of the lock file are not changed anymore
  • Support for sync-token
  • Support for client-side SSL certificates
  • Rights plugins can decide if access to an item is granted explicitly
    • Respond with 403 instead of 404 for principal collections of non-existing users when owner_only plugin is used (information leakage)
  • Authentication plugins can provide the login and password from the environment
    • new remote_user plugin, that gets the login from the REMOTE_USER environment variable (for WSGI server)
    • new http_x_remote_user plugin, that gets the login from the X-Remote-User HTTP header (for reverse proxies)

May 27, 2017 - Radicale 2.0.0

Radicale 2.0.0 is out!

2.0.0 - Little Big Radish

This feature is not compatible with the 1.x.x versions. Follow our migration guide if you want to switch from 1.x.x to 2.0.0.

  • Support Python 3.3+ only, Python 2 is not supported anymore
  • Keep only one simple filesystem-based storage system
  • Remove built-in Git support
  • Remove built-in authentication modules
  • Keep the WSGI interface, use Python HTTP server by default
  • Use a real iCal parser, rely on the "vobject" external module
  • Add a solid calendar discovery
  • Respect the difference between "files" and "folders", don't rely on slashes
  • Remove the calendar creation with GET requests
  • Be stateless
  • Use a file locker
  • Add threading
  • Get atomic writes
  • Support new filters
  • Support read-only permissions
  • Allow External plugins for authentication, rights management, storage and version control

This release concludes endless months of hard work from the community. You, all users and contributors, deserve a big thank you.

This project has been an increadible experience for me, your dear Guillaume, creator and maintainer of Radicale. After more than 8 years of fun, I think that it's time to open this software to its contributors. Radicale can grow and become more than the toy it used to be. I've always seen Radicale as a small and simple piece of code, and I don't want to prevent people from adding features just because I can't or don't want to maintain them. The community is now large enough to handle this.

If you're interested in Radicale, you can read #372 and build its future.

May 3, 2017 - Radicale 1.1.2

Radicale 1.1.2 is out!

1.1.2 - Third Law of Nature

  • Security fix: Add a random timer to avoid timing oracles and simple bruteforce attacks when using the htpasswd authentication method.
  • Various minor fixes.

December 31, 2015 - Radicale 1.1

Radicale 1.1 is out!

1.1 - Law of Nature

One feature in this release is not backward compatible:

  • Use the first matching section for rights (inspired from daald)

Now, the first section matching the path and current user in your custom rights file is used. In the previous versions, the most permissive rights of all the matching sections were applied. This new behaviour gives a simple way to make specific rules at the top of the file independant from the generic ones.

Many improvements in this release are related to security, you should upgrade Radicale as soon as possible:

  • Improve the regex used for well-known URIs (by Unrud)
  • Prevent regex injection in rights management (by Unrud)
  • Prevent crafted HTTP request from calling arbitrary functions (by Unrud)
  • Improve URI sanitation and conversion to filesystem path (by Unrud)
  • Decouple the daemon from its parent environment (by Unrud)

Some bugs have been fixed and little enhancements have been added:

  • Assign new items to corret key (by Unrud)
  • Avoid race condition in PID file creation (by Unrud)
  • Improve the docker version (by cdpb)
  • Encode message and commiter for git commits
  • Test with Python 3.5

September 14, 2015 - Radicale 1.0, what's next?

Radicale 1.0 is out!

1.0 - Sunflower

  • Enhanced performances (by Mathieu Dupuy)
  • Add MD5-APR1 and BCRYPT for htpasswd-based authentication (by Jan-Philip Gehrcke)
  • Use PAM service (by Stephen Paul Weber)
  • Don't discard PROPPATCH on empty collections (Markus Unterwaditzer)
  • Write the path of the collection in the git message (Matthew Monaco)
  • Tests launched on Travis

As explained in a previous mail, this version is called 1.0 because:

  • there are no big changes since 0.10 but some small changes are really useful,
  • simple tests are now automatically launched on Travis, and more can be added in the future (https://travis-ci.org/Kozea/Radicale).

This version will be maintained with only simple bug fixes on a separate git branch called 1.0.x.

Now that this milestone is reached, it's time to think about the future. When Radicale has been created, it was just a proof-of-concept. The main goal was to write a small, stupid and simple CalDAV server working with Lightning, using no external libraries. That's how we created a piece of code that's (quite) easy to understand, to use and to hack.

The first lines have been added to the SVN (!) repository as I was drinking beers at the very end of 2008. It's now packaged for a growing number of Linux distributions.

And that was fun going from here to there thanks to you. So… Thank you, you're amazing. I'm so glad I've spent endless hours fixing stupid bugs, arguing about databases and meeting invitations, reading incredibly interesting RFCs and debugging with the fabulous clients from Apple. I mean: that really, really was really, really cool :).

During these years, a lot of things have changed and many users now rely on Radicale in production. For example, I use it to manage medical calendars, with thousands requests per day. Many people are happy to install Radicale on their small home servers, but are also frustrated by performance and unsupported specifications when they're trying to use it seriously.

So, now is THE FUTURE! I think that Radicale 2.0 should:

  • rely on a few external libraries for simple critical points (dealing with HTTP and iCal for example),
  • be thread-safe,
  • be small,
  • be documented in a different way (for example by splitting the client part from the server part, and by adding use cases),
  • let most of the "auth" modules outside in external modules,
  • have more and more tests,
  • have reliable and faster filesystem and database storage mechanisms,
  • get a new design :).

I'd also secretly love to drop the Python 2.x support.

These ideas are not all mine (except from the really, really, really important "design" point :p), they have been proposed by many developers and users. I've just tried to gather them and keep points that seem important to me.

Other points have been discussed with many users and contibutors, including:

  • support of other clients, including Windows and BlackBerry phones,
  • server-side meeting invitations,
  • different storage system as default (or even unique?).

I'm not a huge fan of these features, either because I can't do anything about them, or because I think that they're Really Bad Ideas®™. But I'm ready to talk about them, because, well, I may not be always right!

Need to talk about this? You know how to contact us!

January 12, 2015 - Radicale 0.10

Radicale 0.10 is out!

0.10 - Lovely Endless Grass

  • Support well-known URLs (by Mathieu Dupuy)
  • Fix collection discovery (by Markus Unterwaditzer)
  • Reload logger config on SIGHUP (by Élie Bouttier)
  • Remove props files when deleting a collection (by Vincent Untz)
  • Support salted SHA1 passwords (by Marc Kleine-Budde)
  • Don't spam the logs about non-SSL IMAP connections to localhost (by Giel van Schijndel)

This version should bring some interesting discovery and auto-configuration features, mostly with Apple clients.

Lots of love and kudos for the people who have spent hours to test features and report issues, that was long but really useful (and some of you have been really patient :p).

Issues are welcome, I'm sure that you'll find horrible, terrible, crazy bugs faster than me. I'll release a version 0.10.1 if needed.

What's next? It's time to fix and improve the storage methods. A real API for the storage modules is a good beginning, many pull requests are already ready to be discussed and merged, and we will probably get some good news about performance this time. Who said "databases, please"?

July 12, 2013 - Radicale 0.8

Radicale 0.8 is out!

0.8 - Rainbow

  • New authentication and rights management modules (by Matthias Jordan)
  • Experimental database storage
  • Command-line option for custom configuration file (by Mark Adams)
  • Root URL not at the root of a domain (by Clint Adams, Fabrice Bellet, Vincent Untz)
  • Improved support for iCal, CalDAVSync, CardDAVSync, CalDavZAP and CardDavMATE
  • Empty PROPFIND requests handled (by Christoph Polcin)
  • Colon allowed in passwords
  • Configurable realm message

This version brings some of the biggest changes since Radicale's creation, including an experimental support of database storage, clean authentication modules, and rights management finally designed for real users.

So, dear user, be careful: this version changes important things in the configuration file, so check twice that everything is OK when you update to 0.8, or you can have big problems.

More and more clients are supported, as a lot of bug fixes and features have been added for this purpose. And before you ask: yes, 2 web-based clients, CalDavZAP and CardDavMATE, are now supported!

Even if there has been a lot of time to test these new features, I am pretty sure that some really annoying bugs have been left in this version. We will probably release minor versions with bugfixes during the next weeks, and it will not take one more year to reach 0.8.1.

The documentation has been updated, but some parts are missing and some may be out of date. You can report bugs or even write documentation directly on GitHub if you find something strange (and you probably will).

If anything is not clear, or if the way rights work is a bit complicated to understand, or if you are so happy because everything works so well, you can share your thoughts!

It has been a real pleasure to work on this version, with brilliant ideas and interesting bug reports from the community. I'd really like to thank all the people reporting bugs, chatting on IRC, sending mails and proposing pull requests: you are awesome.

August 3, 2012 - Radicale 0.7.1

Radicale 0.7.1 is out!

0.7.1 - Waterfalls

  • Many address books fixes
  • New IMAP ACL (by Daniel Aleksandersen)
  • PAM ACL fixed (by Daniel Aleksandersen)
  • Courier ACL fixed (by Benjamin Frank)
  • Always set display name to collections (by Oskari Timperi)
  • Various DELETE responses fixed

It's been a long time since the last version… As usual, many people have contributed to this new version, that's a pleasure to get these pull requests.

Most of the commits are bugfixes, especially about ACL backends and address books. Many clients (including aCal and SyncEvolution) will be much happier with this new version than with the previous one.

By the way, one main new feature has been added: a new IMAP ACL backend, by Daniel. And about authentication, exciting features are coming soon, stay tuned!

Next time, as many mails have come from angry and desperate coders, tests will be finally added to help them to add features and fix bugs. And after that, who knows, it may be time to release Radicale 1.0…

March 22, 2012 - Radicale 0.7

Radicale 0.7 is out, at least!

0.7 - Eternal Sunshine

  • Repeating events
  • Collection deletion
  • Courier and PAM authentication methods
  • CardDAV support
  • Custom LDAP filters supported

A lot of people have reported bugs, proposed new features, added useful code and tested many clients. Thank you Lynn, Ron, Bill, Patrick, Hidde, Gerhard, Martin, Brendan, Vladimir, and everybody I've forgotten.

January 5, 2012 - Radicale 0.6.4, News from Calypso

New year, new release. Radicale 0.6.4 has a really short changelog:

0.6.4 - Tulips

  • Fix the installation with Python 3.1

The bug was in fact caused by a bug in Python 3.1, everything should be OK now.


After a lot of changes in Radicale, Keith Packard has decided to launch a fork called Calypso, with nice features such as a Git storage mechanism and a CardDAV support.

There are lots of differences between the two projects, but the final goal for Radicale is to provide these new features as soon as possible. Thanks to the work of Keith and other people on GitHub, a basic CardDAV support has been added in the carddav branch and already works with Evolution. Korganizer also works with existing address books, and CardDAV-Sync will be tested soon. If you want to test other clients, please let us know!

November 3, 2011 - Radicale 0.6.3

Radicale version 0.6.3 has been released, with bugfixes that could be interesting for you!

0.6.3 - Red Roses

  • MOVE requests fixed
  • Faster REPORT answers
  • Executable script moved into the package

What's New Since 0.6.2?

The MOVE requests were suffering a little bug that is fixed now. These requests are only sent by Apple clients, Mac users will be happy.

The REPORT request were really, really slow (several minutes for large calendars). This was caused by an awful algorithm parsing the entire calendar for each event in the calendar. The calendar is now only parsed three times, and the events are found in a Python list, turning minutes into seconds! Much better, but far from perfection…

Finally, the executable script parsing the command line options and starting the HTTP servers has been moved from the radicale.py file into the radicale package. Two executable are now present in the archive: the good old radicale.py, and bin/radicale. The second one is only used by setup.py, where the hack used to rename radicale.py into radicale has therefore been removed. As a consequence, you can now launch Radicale with the simple python -m radicale command, without relying on an executable.

Time for a Stable Release!

The next release may be a stable release, symbolically called 1.0. Guess what's missing? Tests, of course!

A non-regression testing suite, based on the clients' requests, will soon be added to Radicale. We're now thinking about a smart solution to store the tests, to represent the expected answers and to launch the requests. We've got crazy ideas, so be prepared: you'll definitely want to write tests during the next weeks!

Repeating events, PAM and Courier authentication methods have already been added in master. You'll find them in the 1.0 release!

What's Next?

Being stable is one thing, being cool is another one. If you want some cool new features, you may be interested in:

  • WebDAV and CardDAV support
  • Filters and rights management
  • Multiple storage backends, such as databases and git
  • Freebusy periods
  • Email alarms

Issues have been reported in the bug tracker, you can follow there the latest news about these features. Your beloved text editor is waiting for you!

September 27, 2011 - Radicale 0.6.2

0.6.2 is out with minor bugfixes.

0.6.2 - Seeds

  • iPhone and iPad support fixed
  • Backslashes replaced by slashes in PROPFIND answers on Windows
  • PyPI archive set as default download URL

August 28, 2011 - Radicale 0.6.1, Changes, Future

As previously imagined, a new 0.6.1 version has been released, mainly fixing obvious bugs.

0.6.1 - Growing Up

  • Example files included in the tarball
  • htpasswd support fixed
  • Redirection loop bug fixed
  • Testing message on GET requests

The changelog is really small, so there should be no real new problems since 0.6. The example files for logging, FastCGI and WSGI are now included in the tarball, for the pleasure of our dear packagers!

A new branch has been created for various future bug fixes. You can expect to get more 0.6.x versions, making this branch a kind of "stable" branch with no big changes.

GitHub, Mailing List, New Website

A lot of small changes occurred during the last weeks.

If you're interested in code and new features, please note that we moved the project from Gitorious to GitHub. Being hosted by Gitorious was a nice experience, but the service was not that good and we were missing some useful features such as git hooks. Moreover, GitHub is really popular, we're sure that we'll meet a lot of kind users and coders there.

We've also created a mailing-list on Librelist to keep a public trace of the mails we're receiving. It a bit empty now, but we're sure that you'll soon write us some kind words. For example, you can tell us what you think of our new website!

Future Features

In the next weeks, new exciting features are coming in the master branch! Some of them are almost ready:

  • Henry-Nicolas has added the support for the PAM and Courier-Authdaemon authentication mechanisms.
  • An anonymous called Keith Packard has prepared some small changes, such as one file per event, cache and git versioning. Yes. Really.

As you can find in the Radicale Roadmap, tests, rights and filters are expected for 0.7.

August 1, 2011 - Radicale 0.6 Released

Time for a new release with a lot of new exciting features!

0.6 - Sapling

  • WSGI support
  • IPv6 support
  • Smart, verbose and configurable logs
  • Apple iCal 4 and iPhone support (by Łukasz Langa)
  • CalDAV-Sync support (by Marten Gajda)
  • aCal support
  • KDE KOrganizer support
  • LDAP auth backend (by Corentin Le Bail)
  • Public and private calendars (by René Neumann)
  • PID file
  • MOVE requests management
  • Journal entries support
  • Drop Python 2.5 support

Well, it's been a little longer than expected, but for good reasons: a lot of features have been added, and a lot of clients are known to work with Radicale, thanks to kind contributors. That's definitely good news! But…

Testing all the clients is really painful, moreover for the ones from Apple (I have no Mac nor iPhone of my own). We should seriously think of automated tests, even if it's really hard to maintain, and maybe not that useful. If you're interested in tests, you can look at the wonderful regression suite of DAViCal.

The new features, for example the WSGI support, are also poorly documented. If you have some Apache or lighttpd configuration working with Radicale, you can make the world a little bit better by writing a paragraph or two in the Radicale documentation. It's simple plain text, don't be afraid!

Because of all these changes, Radicale 0.6 may be a little bit buggy; a 0.6.1 will probably be released soon, fixing small problems with clients and features. Get ready to report bugs, I'm sure that you can find one (and fix it)!

July 2, 2011 - Feature Freeze for 0.6

According to the roadmap, a lot of features have been added since Radicale 0.5, much more than expected. It's now time to test Radicale with your favourite client and to report bugs before we release the next stable version!

Last week, the iCal and iPhone support written by Łukasz has been fixed in order to restore the broken Lightning support. After two afternoons of tests with Rémi, we managed to access the same calendar with Lightning, iCal, iPhone and Evolution, and finally discovered that CalDAV could also be a perfect instant messaging protocol between a Mac, a PC and a phone.

After that, we've had the nice surprise to see events displayed without a problem (but after some strange steps of configuration) by aCal on Salem's Android phone.

It was Friday, fun fun fun fun.

So, that's it: Radicale supports Lightning, Evolution, Kontact, aCal for Android, iPhone and iCal. Of course, before releasing a new tarball:

  • documentation is needed for the new clients that are not documented yet (Kontact, aCal and iPhone);
  • tests are welcome, particularly for the Apple clients that I can't test anymore;
  • no more features will be added, they'll wait in separate branches for the 0.7 development.

Please report bugs if anything goes wrong during your tests, or just let us know by Jabber or by mail if everything is OK.

May 1, 2011 - Ready for WSGI

Here it is! Radicale is now ready to be launched behind your favourite HTTP server (Apache, Lighttpd, Nginx or Tomcat for example). That's really good news, because:

  • Real HTTP servers are much more efficient and reliable than the default Python server used in Radicale;
  • All the authentication backends available for your server will be available for Radicale;
  • Thanks to flup, Radicale can be interfaced with all the servers supporting CGI, AJP, FastCGI or SCGI;
  • Radicale works very well without any additional server, without any dependencies, without configuration, just as it was working before;
  • This one more feature removes useless code, less is definitely more.

The WSGI support has only be tested as a stand-alone executable and behind Lighttpd, you should definitely try if it works with you favourite server too!

No more features will be added before (quite) a long time, because a lot of documentation and test is waiting for us. If you want to write tutorials for some CalDAV clients support (iCal, Android, iPhone), HTTP servers support or logging management, feel free to fork the documentation git repository and ask for a merge. It's plain text, I'm sure you can do it!

April 30, 2011 - Apple iCal Support

After a long, long work, the iCal support has finally been added to Radicale! Well, this support is only for iCal 4 and is highly experimental, but you can test it right now with the git master branch. Bug reports are welcome!

Dear MacOS users, you can thank all the gentlemen who sended a lot of debugging iformation. Special thanks to Andrew from DAViCal, who helped us a lot with his tips and his tests, and Rémi Hainaud who lent his laptop for the final tests.

The default server address is localhost:5232/user/, where calendars can be added. Multiple calendars and owner-less calendars are not tested yet, but they should work quite well. More documentation will be added during the next days. It will then be time to release the Radicale 0.6 version, and work on the WSGI support.

April 25, 2011 - Two Features and One New Roadmap

Two features have just reached the master branch, and the roadmap has been refreshed.

LDAP Authentication

Thanks to Corentin, the LDAP authentication is now included in Radicale. The support is experimental and may suffer unstable connexions and security problems. If you are interested in this feature (a lot of people seem to be), you can try it and give some feedback.

No SSL support is included yet, but this may be quite easy to add. By the way, serious authentication methods will rely on a "real" HTTP server, as soon as Radicale supports WSGI.

Journal Entries

Mehmet asked for the journal entries (aka. notes or memos) support, that's done! This also was an occasion to clean some code in the iCal parser, and to add a much better management of multi-lines entries. People experiencing crazy X-RADICALE-NAME entries can now clean their files, Radicale won't pollute them again.

New Roadmap

Except from htpasswd and LDAP, most of the authentication backends (database, SASL, PAM, user groups) are not really easy to include in Radicale. The easiest solution to solve this problem is to give Radicale a CGI support, to put it behind a solid server such as Apache. Of course, CGI is not enough: a WSGI support is quite better, with the FastCGI, AJP and SCGI backends offered by flup. Quite exciting, isn't it?

That's why it was important to add new versions on the roadmap. The 0.6 version is now waiting for the Apple iCal support, and of course for some tests to kill the last remaining bugs. The only 0.7 feature will be WSGI, allowing many new authentication methods and a real multithread support.

After that, 0.8 may add CalDAV rights and filters, while 1.0 will draw thousands of rainbows and pink unicorns (WebDAV sync, CardDAV, Freebusy). A lot of funky work is waiting for you, hackers!


Many bugs have also been fixed, most of them due to the owner-less calendars support. Radicale 0.6 may be out in a few weeks, you should spend some time testing the master branch and filling the bug tracker.

April 10, 2011 - New Features

Radicale 0.5 was released only 8 days ago, but 3 new features have already been added to the master branch:

  • IPv6 support, with multiple addresses/ports support
  • Logs and debug mode
  • Owner-less calendars

Most of the code has been written by Necoro and Corentin, and that was not easy at all: Radicale is now multithreaded! For sure, you can find many bugs and report them on the bug tracker. And if you're fond of logging, you can even add a default configuration file and more debug messages in the source.

April 2, 2011 - Radicale 0.5 Released

Radicale 0.5 is out! Here is what's new:

0.5 - Historical Artifacts

  • Calendar depth
  • iPhone support
  • MacOS and Windows support
  • HEAD requests management
  • htpasswd user from calendar path

iPhone support, but no iCal support for 0.5, despite our hard work, sorry! After 1 month with no more activity on the dedicated bug, it was time to forget it and hack on new awesome features. Thanks for your help, dear Apple users, I keep the hope that one day, Radicale will work with you!

So, what's next? As promised, some cool git branches will soon be merged, with LDAP support, logging, IPv6 and anonymous calendars. Sounds pretty cool, heh? Talking about new features, more and more people are asking for a CardDAV support in Radicale. A git branch and a feature request are open, feel free to hack and discuss.

February 3, 2011 - Jabber Room and iPhone Support

After a lot of help and testing work from Andrew, Björn, Anders, Dorian and Pete (and other ones we could have forgotten), a simple iPhone support has been added in the git repository. If you are interested, you can test this feature right now by downloading the latest git version (a tarball is even available too if you don't want or know how to use git).

No documentation has been written yet, but using the right URL in the configuration should be enough to synchronize your calendars. If you have any problems, you can ask by joining our new Jabber room: radicale@room.jabber.kozea.fr.

Radicale 0.5 will be released as soon as the iCal support is ready. If you have an Apple computer, Python skills and some time to spend, we'd be glad to help you debugging Radicale.

October 21, 2010 - News from Radicale

During the last weeks, Radicale has not been idle, even if no news have been posted since August. Thanks to Pete, Pierre-Philipp and Andrew, we're trying to add a better support on MacOS, Windows and mobile devices like iPhone and Android-based phones.

All the tests on Windows have been successful: launching Radicale and using Lightning as client works without any problems. On Android too, some testers have reported clients working with Radicale. These were the good news.

The bad news come from Apple: both iPhone and MacOS default clients are not working yet, despite the latest enhancements given to the PROPFIND requests. The problems are quite hard to debug due to our lack of Apple hardware, but Pete is helping us in this difficult quest! Radicale 0.5 will be out as soon as these two clients are working.

Some cool stuff is coming next, with calendar collections and groups, and a simple web-based CalDAV client in early development. Stay tuned!

August 8, 2010 - Radicale 0.4 Released

Radicale 0.4 is out! Here is what's new:

0.4 - Hot Days Back

  • Personal calendars
  • HEAD requests
  • Last-Modified HTTP header
  • no-ssl and foreground options
  • Default configuration file

This release has mainly been released to help our dear packagers to include a default configuration file and to write init scripts. Big thanks to Necoro for his work on the new Gentoo ebuild!

July 4, 2010 - Three Features Added Last Week

Some features have been added in the git repository during the last weeks, thanks to Jerome and Mariusz!

Personal Calendars Calendars accessed through the htpasswd ACL module can now be personal. Thanks to the personal option, a user called bob can access calendars at /bob/* but not to the /alice/* ones.

HEAD Requests Radicale can now answer HEAD requests. HTTP headers can be retrieved thanks to this request, without getting contents given by the GET requests.

Last-Modified HTTP header The Last-Modified header gives the last time when the calendar has been modified. This is used by some clients to cache the calendars and not retrieving them if they have not been modified.

June 14, 2010 - Radicale 0.3 Released

Radicale 0.3 is out! Here is what’s new:

0.3 - Dancing Flowers

  • Evolution support
  • Version management

The website changed a little bit too, with some small HTML5 and CSS3 features such as articles, sections, transitions, opacity, box shadows and rounded corners. If you’re reading this website with Internet Explorer, you should consider using a standard-compliant browser!

Radicale is now included in Squeeze, the testing branch of Debian. A Radicale ebuild for Gentoo has been proposed too. If you want to package Radicale for another distribution, you’re welcome!

Next step is 0.5, with calendar collections, and Windows and MacOS support.

May 31, 2010 - May News

News from contributors

Jonas Smedegaard packaged Radicale for Debian last week. Two packages, called radicale for the daemon and python-radicale for the module, have been added to Sid, the unstable branch of Debian. Thank you, Jonas!

Sven Guckes corrected some of the strange-English-sentences present on this website. Thank you, Sven!

News from software

A simple VERSION has been added in the library: you can now play with radicale.VERSION and $radicale --version.

After playing with the version (should not be too long), you may notice that the next version is called 0.3, and not 0.5 as previously decided. The 0.3 main goal is to offer the support for Evolution as soon as possible, without waiting for the 0.5. After more than a month of test, we corrected all the bugs we found and everything seems to be fine; we can imagine that a brand new tarball will be released during the first days of June.

April 19, 2010 - Evolution Supported

Radicale now supports another CalDAV client: Evolution, the default mail, addressbook and calendaring client for Gnome. This feature was quite easy to add, as it required less than 20 new lines of code in the requests handler.

If you are interested, just clone the git repository.

April 13, 2010 - Radicale 0.2 Released

Radicale 0.2 is out! Here is what’s new:

0.2 - Snowflakes

  • Sunbird pre-1.0 support
  • SSL connection
  • Htpasswd authentication
  • Daemon mode
  • User configuration
  • Twisted dependency removed
  • Python 3 support
  • Real URLs for PUT and DELETE
  • Concurrent modification reported to users
  • Many bugs fixed by Roger Wenham

First of all, we would like to thank Roger Wenham for his bugfixes and his supercool words.

You may have noticed that Sunbird 1.0 has not been released, but according to the Mozilla developers, 1.0pre is something like a final version.

You may have noticed too that Radicale can be downloaded from PyPI. Of course, it is also available on the download page.

January 21, 2010 - HTTPS and Authentication

HTTPS connections and authentication have been added to Radicale this week. Command-line options and personal configuration files are also ready for test. According to the TODO file included in the package, the next version will finally be 0.2, when sunbird 1.0 is out. Go, Mozilla hackers, go!

HTTPS connection HTTPS connections are now available using the standard TLS mechanisms. Give Radicale a private key and a certificate, and your data are now safe.

Authentication A simple authentication architecture is now available, allowing different methods thanks to different modules. The first two modules are fake (no authentication) and htpasswd (authentication with an htpasswd file created by the Apache tool). More methods such as LDAP are coming soon!

January 15, 2010 - Ready for Python 3

Dropping Twisted dependency was the first step leading to another big feature: Radicale now works with Python 3! The code was given a small cleanup, with some simplifications mainly about encoding. Before the 0.1.1 release, feel free to test the git repository, all Python versions from 2.5 should be OK.

January 11, 2010 - Twisted no Longer Required

Good news! Radicale 0.1.1 will support Sunbird 1.0, but it has another great feature: it has no external dependency! Twisted is no longer required for the git version, removing about 50 lines of code.

December 31, 2009 - Lightning and Sunbird 1.0b2pre Support

Lightning/Sunbird 1.0b2pre is out, adding minor changes in CalDAV support. A new commit makes Radicale work with versions 0.9, 1.0b1 et 1.0b2. Moreover, etags are now quoted according to the RFC 2616.

December 9, 2009 - Thunderbird 3 released

Thunderbird 3 is out, and Lightning/Sunbird 1.0 should be released in a few days. The last commit in git should make Radicale work with versions 0.9 and 1.0b1pre. Radicale 0.1.1 will soon be released adding support for version 1.0.

September 1, 2009 - Radicale 0.1 Released

First Radicale release! Here is the changelog:

0.1 - Crazy Vegetables

  • First release
  • Lightning/Sunbird 0.9 compatibility
  • Easy installer

You can download this version on the download page.

July 28, 2009 - Radicale on Gitorious

Radicale code has been released on Gitorious! Take a look at the Radicale main page on Gitorious to view and download source code.

July 27, 2009 - Radicale Ready to Launch

The Radicale Project is launched. The code has been cleaned up and will be available soon…