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How to set up and populate an update site


This tutorial explains how to set up a website to distribute your plugins. It assumes that your plugins are correctly installed in your local ImageJ setup.


See the Distribution page for a discussion of the benefits of update sites and how they fit in to plugin development.

Add your personal update site

Please note that since the Wiki relaunch, personal update sites are no longer hosted through the ImageJ Wiki. Existing upload credentials are unaffected - but the process for creating/updating credentials has changed.

By far the easiest method to provide your macros, scripts and plugins to other users, letting them keep up-to-date in the most convenient manner, is to set up your personal update site.

A personal update site is hosted on<update-site-name>. In the past, each update site corresponded directly to ImageJ Wiki user accounts - but now, a particular user can have upload access to many sites, and a particular update site can have many authorized users.

There are some minimal Terms of Service for personal update sites. See the Personal Update Site Terms of Service for details.

First of all, please use this thread on the forum to request a new upload account and/or new update site. You can also request the addition or removal of uploader permissions of a given user to a particular site, or request a password reset for your upload account.

If you need to create a new upload account as part of this process, your password will be PM’d to you by a forum admin.

To start using your update site, in ImageJ start the updater with HelpUpdate and click on the Manage update sites button:

Specifying your site

Click the Add update site button.

Optionally, enter a nickname for your site in the Name column. In the URL column, enter your site’s complete URL. Finally, in the Host column, enter webdav:<your-uploader-username>

Dedicated plugin update sites

Rather than having a single update site for many plugins, it is highly advised to set up dedicated update sites for each plugin that could be of interest to the community.
Such dedicated update site can have a more intuitive name.
A given upload account can own several update sites. To request a new update site for your user account, post your request on the forum (see related post), or on the ImageJ Gitter.

Group update site

In addition to personal update sites, it is possible for groups of people to share an update site.

To create such an update site, post on the Forum, or in the imagej Gitter channel, requesting the creation of the site on, including the desired name of the site, as well as the upload users to be granted upload permission to the group update site. An administrator will then create the site skeleton and grant those users upload permission to the new site.

Adding an update site on your own server

If you have an own server or web space with WebDAV, SFTP or SSH access, you can create a directory in that web space and initialize it as an update site, too. Just call the updater with HelpUpdate and click the Manage update sites button:

Now press the Add button, provide a nick name for your update site, the URL of your web space, and upload information.

The upload information depends on the protocol available for uploading:

Protocol Host Directory on Host
WebDAV webdav:, or *webdav:* .
SFTP *sftp:@* **
SSH *ssh:@* **

In case you want to use an SFTP/SSH server, it must have an empty, public web accessible folder where you intend to publish your updates. The ImageJ updater will not create that empty folder.


A note about SSH and known_hosts: For ImageJ to connect to your server over SSH, you must have configured your SSH credentials as normal—i.e.: $HOME/.ssh/known_hosts must contain the host key, and optionally $HOME/.ssh/config may contain the host configuration/credentials. We recommend that the given host be specified in $HOME/.ssh/config and equipped with a private key.

Note that you need to connect with command-line ssh first, to record the finger-print of the host. It might be necessary to call ssh-keyscan >> $HOME/.ssh/known_hosts to ensure the correctly formatted key appears in your configuration file. There is an issue with newer SSH servers offering host keys in ecdsa-sha2-nistp256 format, but the JSch library wanting them in ssh-rsa format instead. If you receive the error com.jcraft.jsch.JSchException: UnknownHostKey then you might be bitten by this discrepancy; try using the ssh-keyscan invocation above. If you still have trouble, please write to the Forum to troubleshoot further.

Example: Let’s assume you have SFTP access to a machine known as to the internet, and let’s assume that you have a user account myself that has write access to the path /var/www/my-update-site/ on that machine that is served via Then the line you need to add might look like this:

Name URL Host Directory on Host
My Update Site /var/www/my-update-site/

If the update site has not been initialized yet (i.e. if nobody else has initialized that site yet), you will see a dialog like this:

Just click OK and let the updater upload an empty file index (it is stored in the file db.xml.gz which is also called the database in the documentation of the updater).

Uploading files to your update site

Note: you cannot simply copy files to your web space; the updater would miss all kinds of important information, and consequently refuse to accept that update site. You need to let the updater handle the file uploading.

Start the updater and check your update site

First, start the updater:

Click on the Manage update sites button and verify:

  • Your update site is present and enabled
  • The Host column of your update site contains your user name, in the form: webdav:

For example:

Once your login information is set you can Close the update site window.

Prepare your files for upload

Click on the Advanced mode button and set the view options to see your plugins:

  • If your have never uploaded your plugins, select View local-only files

For .ijm macro, the files must be located in the macro or scripts folder (or any subfolder in it).

For .py scripts, they can be either in the Jars/Lib or scripts folder (or any subfolder).

Out of those folder, the updater might not see them.

  • If you are uploading new versions of your plugins, select View locally modified files only

In this case, the plugin we’ll be uploading is contained in A_Jolly_Useful_Plugin.jar.

Select the file to upload, click under the Stats/Action column, or right-click (on macOS, ⌃ Ctrl +  Left Click) in any column, for the context menu and select *Upload to *.

The *Upload to * option is only available if you entered your [upload credentials](#start-the-updater-and-check-your-update-site) and no other changes are pending. This is to avoid potentially corrupting your ImageJ installation. If the Upload option is not available, select the *View changes* view and resolve any pending changes - e.g. by updating or reverting to **Keep as-is**.

Modifying Dependencies

When a plugin is selected, a Details panel becomes available. The plugin’s dependencies, e.g. ij.jar and someJarOrOther.jar, are automatically determined by the updater. Hence if you require 3rd party packages for your plugin you can place them into the jars folder of ImageJ and the updater will automatically upload them to the site.

You can also manually enter or edit any information in the Details panel:

The Details panel can only be edited if you have entered upload credentials for the appropriate update site. After modifying the Details panel you can mark the jar for upload, even though the jar contents itself has not changed.

Sometimes the updater will mis-detect your dependencies. This may prevent you from uploading to your update site! If a dependency is wrong, you can manually add or delete dependencies from the Details tab to correct the problem. Please let us know when this happens so we can try to improve the updater

Upload your files

Finally, click Apply changes (upload) to upload your plugin to the server and allow others to access it. If you have dependencies that are not part of ImageJ, the updater will ask you if you want to upload that jar as well. Finally, you will be asked for your login credentials again and the files will be uploaded to the server.

Check that your plugins are now registered as ImageJ plugins by selecting the View files of the ‘[your site name here]’ site view option:

That’s it - you’re done. Now, anyone who wants a copy of your plugins merely needs to add your update site to the Update manger via the URL you specified, and your plugins will be downloaded and updated in their ImageJ installations just like the standard ImageJ plugins.
For even more visibility and practicability, you can ask to have your update site listed in the Fiji Updater (see section below).

Publishing your update site

If you want your update site to be listed in the ImageJ update manager, follow the instructions at this page : list of update sites .

Further Reading

For additional information on common topics regarding update site maintenance, please see the update site FAQ.