While the message bar of a room is selected, you can type a message that you wish to send. When it’s complete, you can send it by pressing the <Enter> key from either Normal or Insert mode.

If you need to type a multiline message, you can start a line by typing <C-V><C-J>. You can also use the O and o keys to insert a blank line before or after the current line respectively.

From within the message bar, you can complete Matrix usernames, room aliases and identifiers, and Emoji shortcodes (e.g., :heart:) by using <C-N> and <C-P> to start cycling forwards or backwards through the list of possible completions.

The :upload command allows you to specify a file to send to the currently focused room:

:upload "/home/user/Documents/Shared Document.pdf"

Clipboard images can be uploaded by pasting with p or P from the "+ and "* registers, and following the confirmation dialog. On macOS and Windows they contain the same contents, but they differ on Linux and other *nix systems running X11 or Wayland, where:

  • "+ contains the CLIPBOARD selection, which is usually set in a GUI application with <C-C> or by selecting “Copy Image” in a menu dialog.
  • "* contains the PRIMARY selection, which is usually the last selected text in X11 or Wayland.

So, for example, if you had copied an image from a web browser on Linux (placing it into the CLIPBOARD selection), you could paste it into iamb with "+p. Or, if you instead selected some text with your cursor (placing it into the PRIMARY selection), then you could paste it with "*p.

If you want to compose a longer message outside of iamb in your preferred text editor, you can use the :editor command to launch your configured $EDITOR.

Message Scrollback

You can scroll through messages from the message bar using the following keys:

  • <C-E>/<C-Y> to scroll downwards and upwards respectively a line at a time
  • <C-D>/<C-U> to scroll downwards and upwards respectively by half the window height
  • <C-F>/<C-B> to scroll downwards and upwards respectively by the window height

If you want to use movement keys to select individual messages, you can toggle focus between the message bar and the scrollback by pressing <C-W>m.

The plaintext content of messages can be copied to registers using yank keybindings like yy or Y, and marked with m{a-z}. Marked messages can then be returned to via '{a-z}.

You can search the plaintext content of messages using ? and / for reverse and forward search respectively. The n and N keys can be used to jump between results.


You can enter or create a thread by selecting the message in the scrollback and pressing <Enter>. This will open a thread view that will show you messages in that thread. If you send a message in this view, it will be sent in-thread.

Entering the thread view puts an entry into the jumplist, so when you are ready to return to the main room view, you can use ^O to move backwards through the jumplist.

Replying To A Message

If you select a message in the scrollback, you can reply to it using the :reply command. This will refocus the message bar, where you can type out your reply. You can then send it the same way that you would a normal message.

If you change your mind, or select the wrong message to reply to, you can use :cancel to undo your :reply.

Editing Messages

Once a message has been sent, you might find that you need to amend it, to fix typos or correct information. You can select the message and run the :edit command. This will update the text box to include the message’s original body for you to edit.

Once you’ve finished correcting the message, you can send it just like other messages to update the original.

Reacting To A Message

If you want to react to a message with an Emoji, you can select it in the scrollback, and then use the :react command. For example:

:react ❤️

As a convenience, you can use the GitHub Emoji shortcodes to refer to them instead. For example, we could have also written the above as:

:react heart

If you want to remove a reaction, you can do so with the :unreact command. By default, this will remove all your reactions from the specified message, but you can give a name if you’ve made any that you want to keep:

:unreact heart

Redacting A Message

If you need to remove a message from a room, you can do so using the :redact command on the message. This command optionally takes a single argument giving the reason for removing it. For example:

:redact "Message violates room rules"

If you’re removing a message because it contains secrets (e.g. passwords, authentication tokens, etc.), make sure to rotate them: redacting a message prevents people from seeing it in the future, but users in the room at the time it was originally sent may have already seen it, and it may still live in the room logs of some clients or bots.

Downloading Attachments

If you select an attachment in the scrollback, you can download it using the :download command:

  • When given no arguments, iamb will download the attachment to the configured downloads directory
  • When given a directory as an argument, the file will be saved there
  • Otherwise, the file file will be saved to the given path

If there is already a file of the same name, iamb will not overwrite it. You can use :download! to replace the file.

To open the file after downloading the file, use the :open command instead.

Links in messages are each assigned a number (or a letter when there are more than 10 links), which is shown within brackets (like [0]). You can use :open to view a list of their matching URLs, and pick one to open in a browser by typing its assigned character.