Admin and Operations

    Your urbit (also called your ship) is a persistent Unix process that you mainly control from the console. For some things, a browser will also work.


    You can turn your urbit off with Ctrl-d from the Talk or Dojo prompts.

    You can force-quit your urbit with Ctrl-z from anywhere.


    To restart your urbit simply pass the name of your pier:

    $ urbit some-planet


    $ urbit comet


    To log an urbit's command line output to a file, use script:

    $ script urbit.log urbit your-urbit

    Moving your pier

    Piers are designed to be portable, but it must be done while the urbit is turned off. Urbit networking is stateful, so you can't run two copies of the same urbit in two places.

    To move a pier, simply move the contents of the directory it lives in. To keep these files as small as possible we usually use the --sparse option in tar. With a pier your-urbit/, something like this should work:

    tar -Scvzf ~/your-urbit.tar.gz ~/your-urbit/
    scp your-old-server:~/your-urbit.tar.gz your-new-server:~

    Then to unzip it, on your other Unix server, run:

    tar xfvz your-urbit.tar.gz

    Delete the tar file, and, after installing Urbit on your new server, start your urbit back up with:

    urbit your-urbit


    Your Urbit terminal is separated into two parts: the prompt (the bottom line) and the record (everything above that). The record is shared; all the output from all the apps in your command set appears in it. The prompt is multiplexed.

    In the CLI, Urbit apps can process your input before you hit return. To see this in action try entering ) as the first character at the Dojo prompt. Since there is no Dojo command or Hoon expression that starts with ')', the Dojo rejects it.

    Ctrl-x - Switches the prompt between running console apps.

    Ctrl-c - Crash current event. Processed at the Unix layer and prints a stack. trace.

    Ctrl-d - From Talk or Dojo, stops your Urbit process.

    Ctrl-z - Stops the Urbit process from anywhere.

    / - History navigation.

    Backspace - Interrupts running commands. For example, if you have begun a multiline Hoon expression and then press backspace, it will discard the already-written code, or if you press backspace while a request is still pending it will cancel it and print ! cancel /hand.

    The following emacs-style key bindings are available:

    Ctrl-a    Cursor to beginning of the line (Home)
    Ctrl-b    Cursor one character backward (left-arrow)
    Ctrl-e    Cursor to the end of the line (End)
    Ctrl-f    Cursor one character forward (right-arrow)
    Ctrl-g    Beep; cancel reverse-search
    Ctrl-k    Kill to end of line
    Ctrl-l    Clear the screen
    Ctrl-n    Next line in history (down-arrow)
    Ctrl-p    Previous line in history (up-arrow)
    Ctrl-r    Reverse-search
    Ctrl-t    Transpose characters
    Ctrl-u    Kill to beginning of line
    Ctrl-y    Yank from kill buffer

    Full coverage of the Urbit shell, the Dojo is covered in the Shell walkthrough.


    On startup Urbit tries to bind to localhost:80. If you're already running something on port 80 -- such as any other HTTP server, or another urbit -- you'll find the urbit that you just started on 8080, 8081, and so on. For planets only, we also proxy web domains through Urbit's own servers. Any planet ~your-urbit is also at, but only after you set up DNS.

    Your urbit serves a simple homepage from http://localhost or that should be self-explanatory. Since our HTTPS isn't audited / battle tested, we just call it "secure" HTTPS. You can find that on 8443. Or 8444 (and so on) if you're already running something on 8443.


    Planets can spawn moons, which are meant for connected devices: phones, smart TVs, digital thermostats. The basic idea is: your planet runs permanently in a data center somewhere and moons run on all your devices. Each planet can issue ~4 billion (2^32) moons.

    To generate a random moon from your planet, run:

    ~sampel-palnet:dojo> +moon
    moon: ~faswep-navred-sampel-palnet
    \/                                                                                               \/

    You must manually edit the output of +moon to get the correct format for the <key>:

    • strip out the /

    • combine into one line, omitting spaces

    • trim the leading ~.

    <key> would be 0wd.rZU67.3jSny.z1vda ... <snip> ... effP0.de01g.600g1 in this example.

    Put <key> in a file and that file becomes <keyfile>.

    Another way of generating <keyfile> is:

    ~sampel-palnet:dojo> @moon/key +moon
    moon: ~faswep-navred-sampel-palnet

    <keyfile> will be at path/to/sampel-palnet/.urb/put/moon.key and does not need editing to be used with the -k option.

    You can use the resulting output in the same installation flow from the Booting a Ship guide, following the same scheme as for booting a planet. That scheme is:

    $ urbit -w <moonname> -G <key> -c <piername>


    $ urbit -w <moonname> -k <keyfile> -c <piername>

    The -c <piername> argument is not required, but it is recommended; otherwise, the resulting directory is a rather unwieldy moon name.

    Here's how an example moon might be booted:

    $ urbit -w faswep-navred-sampel-palnet -G <key> -c mymoon


    $ urbit -w faswep-navred-sampel-palnet -k <keyfile> -c mymoon

    Moons are automatically synced to their parent %kids desk, and can control applications on their parent planet using |link. You can read more about those operations in the filesystem and console walkthroughs, respectively.

    Continuity breaches

    While the Urbit network is in this alpha state, we sometimes have to reboot the whole network. This happens either when major changes need to be shipped or we hit a bug that can't be fixed over the air.

    Because Urbit networking is stateful we call this a continuity breach. Everything has to be restarted from scratch. Your pier will continue to function after we have breached, but it wont connect to the rest of the Urbit network.

    When this happens, back up any files you'd like to save, shut down your urbit and recreate it (as if you were starting for the first time).