Laurel Kona Goodhart

Computational linguist — Software engineer

Running and Testing an IRC Bot Offline

November 04, 2014

Want to write an irc bot without getting kicked off your favorite server during testing? Not to mention be able to play with it while offline—after all, you shouldn’t have to connect to the internet just to test your chat bot. Recently I was recommended to use Charybdis to set up a local irc server for testing. However, I quickly found a simpler solution, one that’s more or less plug-and-play, with minimal initial setup.

This article assumes a Linux-like operating system for specific instructions on how to run certain commands, but it should be possible to use Mac OS X. As such, some commands may vary.


Prompted by a Physics student teacher’s post about setting up a local IRC server for his students to use, I decided to look into ngIRCd.

Installation is easy enough:

apt-get install ngircd

(You may need to use ‘sudo’)

He goes into slightly more depth about configuring ngird, which you can do by editting the configurations in /etc/ngircd/ngirdc.conf if you like; for simple bot testing, I found this necessary. After installing, simply run


in a terminal to start it. It will look like nothing happened, but you will now be able to connect to your local server using

irssi -c localhost

or whatever your favorite irc client is.

You can stop it at any time by calling

/etc/init.d/ngircd stop

I believe that it will run every time the box on which it’s run is turned on (meaning that shutting down or restarting will only stop ngIRCd while the box is off), though I have not tested that extensively. You can tell if it is running my executing

pidof ngircd

in a terminal. If it returns a pid (a number), then ngircd is running. You can also use this number to kill the job, but there is no reason to do that instead of the stop command above.

Now that the local IRC server is set up, you can use it to test your irc bot by connecting it to localhost.

A Little Bit of Troubleshooting

If you notice that your bot doesn’t seem to be connecting and are extending Twisted’s irc.IRCClient, consider adding

def dataReceived(self, bytes):
        print repr(bytes)
        return irc.IRCClient.dataReceived(self, bytes)

to your bot’s code. This will let you see all the data your bot receives, and may help with troubleshooting a bad connection. For example, when I first tried to connect Promptbot to localhost, it never showed up in the default channel, nor even on the local network. Once I added the above code, I was able to see that it was getting the following message:

ERROR :Access denied: Bad password?

This happened because I had set Promptbot up with a default nick and password. Since no password was configured for the server, it was being rejected for even trying to use a password at all. Once I set the default password to null, it was able to connect, and I was able to test my bot to my heart’s content.

Need help troubleshooting? Feel free to contact me! I’m always open for questions… especially related to Promptbot/irc bots!