Multiuser support

OpenCRAVAT can be installed on a server to support multiple users each with their own login and workspace for analysis results. open-cravat-multiuser is an add-on package to OpenCRAVAT and adds the support for multiple user accounts to OpenCRAVAT (from OpenCRAVAT 1.6.0).

Installation and requirements

Multiuser support is available through pip installation of the open-cravat-multiuser package after a normal installation of the open-cravat pip package.

open-cravat-multiuser requires OpenCRAVAT >= 1.6.0, aiohttp_session, and cryptography pip packages, which will be installed while open-cravat-multiuser is installed, if missing.

Install open-cravat-multiuser package with the following command.

pip install open-cravat-multiuser

Server Configuration

The multiuser OpenCRAVAT should be configured to run on an appropriate port for the server on which it is installed. If port 80 is available, this will generally be the easiest to use. To set the port, first identify where the cravat-system.yml configuration file is located. Type:

oc config system

The first line of output will display the directory of OpenCRAVAT configuration files. In this directory, edit the cravat-system.yml file and set the gui_port to the desired port. Example: gui_port: 80.

Note: you may need to make sure that the firewall on your server allows inbound http / https traffic on the specified port.

OpenCRAVAT can support HTTPS. To setup HTTPS, see here. You can also setup https external to the OpenCRAVAT server in many ways. For example, some reverse proxies perform https to http functions.

Starting Multiuser OpenCRAVAT Server

The multiuser version of OpenCRAVAT is started with the normal oc gui command with the --multiuser option. Since users will generally run this on a remote server, this flag will not open a local browser as oc gui normally does. Start the server with the command:

oc gui --multiuser

Admin Login

The Multiuser OpenCRAVAT Server has a pre-configured administrator login. This login is capable of installing annotators on the server from the OpenCRAVAT store, changing server options, and reviewing general jobs statistics. Initially, the username and the password for the admin account are admin and admin, respectively. We strongly recommend changing the admin password after the initial login.

Admin tab

Admin tab is only displayed for the admin user and shows job statistics for all jobs run on the system. Choose the date range of interest in Date range and click Update. Click Export to get the statistics as a tab-separated file.

Admin - Jobs tab

admin account cannot submit jobs and the job list on the Jobs tab of the main page will show an additional column which will have the username of each job in the list.

Admin System setting

Settings icon (triple bar icon at the top right corner of the main page of OpenCRAVAT web interface) will show only when logged in as admin. Details of the system setting is here. The important settings for an administrator to consider are the ‘Maximum number of concurrent jobs’ and ‘Maximum number of concurrent annotators per job’. These should be tuned to the machine where multiuser OpenCRAVAT is running. Concurrent annotators allow a single job to be processed more quickly and concurrent jobs allow multiple user jobs to be processed in parallel. If too many concurrent jobs and concurrent annotators are allowed to run, the CPUs may be overwhelmed and performance may degrade. It is also possible on this settings tab to change the location of annotators and user jobs to directories that are appropriate for the server.

Admin Store

In a multiuser server, only the admin will have permissions to install modules from the OpenCRAVAT store. Select the Store tab when logged in as admin to see the available modules and to install those that are appropriate for your group.

User account operations

Connecting and Creating a user account

Users can connect to the multiuser OpenCRAVAT server just by entering its URL. If it was configured to run on port 80, a user can just enter the server name and connect to OpenCRAVAT. For example if multiuser OpenCRAVAT was installed on a server with a host name of ‘LabServer’ on port 80, the URL would be:

http://LabServer/’ or ‘https://LabServer

depending on whether https was configured. If it is running on a non-standard port, then the port number would need to be added to the URL. For example:


Click Sign up to create your user account.

Enter your email, password, and password again. Question and Answer are for retrieving your password. Enter your own password retrieval question and answer. Click Create account. If there is any error, the browser will notify. If your account has been successfully created, a success notification will show and you will be redirected to the main page of OpenCRAVAT web interface.


On the login page, enter your email and password and type Enter or click Login. If login is successful, you will be redirected to the main page of OpenCRAVAT web interface.

Retrieving password

If you forgot your password, on the login page, click Forgot password?. Below page will show.

Enter your email and click Get password question. You will be directed to the next page of password retrieval, which will show the password retrieval question you entered while creating your account.

Type the password retrieval answer you entered while creating your account and click Submit. If the answer is right, a popup will show which states that your password has been reset to a temporary password shown on the popup.

Click Ok on the popup and the browser will show the login page again. Enter your email and the temporary password to login. You will be redirected to the main page of OpenCRAVAT web interface.

Change password

At the top right corner of the main page of OpenCRAVAT web interface, your email, change password icon, and logout icon are shown.

Click the change password icon to change your password. Enter your current password in Old password, and a new password in both New password and Retype new password. Click Submit to finish the password change.


Click the logout button to logout. You will be redirected to the login page.