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Bridging the gap between XMPP and shell scripts

In a previous post, I set up a semi-automated backup system for my Raspberry Pi using duplicity, sendxmpp, and an external drive. It's been working fabulously for a while now, but unfortunately the other week sendxmpp suddenly stopped working with no obvious explanation. Given the long list of arguments I had to pass it:

sendxmpp --file "${xmpp_config_file}" --resource "${xmpp_resource}" --tls --chatroom "${xmpp_target_chatroom}" ...........

....and the fact that I've had to tweak said arguments on a number of occasions, I thought it was time to switch it out for something better suited to the task at hand.

Unfortunately, finding such a tool proved to be a challenge. I even asked on Reddit - but nobody had anything that fit the bill (xmpp-bridge wouldn't compile correctly - and didn't support multi-user chatrooms anyway, and xmpppy was broken too).

If you're unsure as to what XMPP is, I'd recommend checkout out either this or this tutorial. They both give a great introduction to what it is, what it does, and how it works - and the rest of this post will make much more sense if you read that first :-)

To this end, I finally gave in and wrote my own tool, which I've called xmppbridge. It's a global Node.JS script that uses the simple-xmpp to forward the standard input to a given JID over XMPP - which can optionally be a group chat.

In this post, I'm going to look at how I put it together, some of the issues I ran into along the way, and how I solved them. If you're interested in how to install and use it, then the package page on npm will tell you everything you need to know:

xmppbridge on npm

Architectural Overview

The script consists of 3 files:

  • index.sh - Calls the main script with ES6 modules enabled
  • index.mjs - Parses the command-line arguments and environment variables out, and provides a nice CLI
  • XmppBridge.mjs - The bit that actually captures input from stdin and sends it via XMPP

Let's look at each of these in turn - starting with the command-line interface.

CLI Parsing

The CLI itself is relatively simple - and follows a paradigm I've used extensively in C♯ (although somewhat modified of course to get it to work in Node.JS, and without fancy ANSI colouring etc.).

#!/usr/bin/env node
"use strict";

import XmppBridge from './XmppBridge.mjs';

const settings = {
    jid: process.env.XMPP_JID,
    destination_jid: null,
    is_destination_groupchat: false,
    password: process.env.XMPP_PASSWORD
};

let extras = [];
// The first arg is the script name itself
for(let i = 1; i < process.argv.length; i++) {
    if(!process.argv[i].startsWith("-")) {
        extras.push(process.argv[i]);
        continue;
    }

    switch(process.argv[i]) {
        case "-h":
        case "--help":
            // ........
            break;

        // ........

        default:
            console.error(`Error: Unknown argument '${process.argv[i]}'.`);
            process.exit(2);
            break;
    }
}

We start with a shebang, telling Linux-based systems to execute the script with Node.JS. Following that, we import the XmppBridge class that's located in XmppBrdige.mjs (we'll come back to this later). Then, we define an object to hold our settings - and pull in the environment variables along with defining some defaults for other parameters.

With that setup, we can then parse the command-line arguments themselves - using the exact same paradigm I've used time and time again in C♯.

Once the command-line arguments are parsed, we validate the final settings to ensure that the user hasn't left any required parameters undefined:

for(let environment_varable of ["XMPP_JID", "XMPP_PASSWORD"]) {
    if(typeof process.env[environment_varable] == "undefined") {
        console.error(`Error: The environment variable ${environment_varable} wasn't found.`);
        process.exit(1);
    }
}

if(typeof settings.destination_jid != "string") {
    console.error("Error: No destination jid specified.");
    process.exit(5);
}

That's basically all that index.mjs does. All that's really left is passing the parameters to an instance of XmppBridge:

const bridge = new XmppBridge(
    settings.destination_jid,
    settings.is_destination_groupchat
);
bridge.start(settings.jid, settings.password);

Shebang Trouble

Because I've used ES6 modules here, currently Node must be informed of this via the --experimental-modules CLI argument like this:

node --experimental-modules ./index.mjs

If we're going to make this a global command-line tool via the bin directive in package.json, then we're going to have to ensure that this flag gets passed to Node and not our program. While we could alter the shebang, that comes with the awkward problem that not all systems (in fact relatively few) support using both env and passing arguments. For example, this:

#!/usr/bin/env node --experimental-modules

Wouldn't work, because env doesn't recognise that --experimental-modules is actually a command-line argument and not part of the binary name that it should search for. I did see some Linux systems support env -S to enable this functionality, but it's hardly portable and doesn't even appear to work all the time anyway - so we'll have to look for another solution.

Another way we could do it is by dropping the env entirely. We could do this:

#!/usr/local/bin/node --experimental-modules

...which would work fine on my system, but probably not on anyone else's if they haven't installed Node to the same place. Sadly, we'll have to throw this option out the window too. We've still got some tricks up our sleeve though - namely writing a bash wrapper script that will call node telling it to execute index.mjs with the correct arguments. After a little bit of fiddling, I came up with this:

#!/usr/bin/env bash
install_dir="$(dirname "$(readlink -f $0)")";
exec node --experimental-modules "${install_dir}/index.mjs" $@

2 things are at play here. Firstly, we have to deduce where the currently executing script actually lies - as npm uses a symbolic link to allow a global command-line tool to be 'found'. Said symbolic link gets put in /usr/local/bin/ (which is, by default, in the user's PATH), and links to where the script is actually installed to.

To figure out the directory that we've been installed to is (and hence the location of index.mjs), we need to dereference the symbolic link and strip the index.sh filename away. This can be done with a combination of readlink -f (dereferences the symbolic link), dirname (get the parent directory of a given file path), and $0 (holds the path to the currently executing script in most circumstances) - which, in the case of the above, gets put into the install_dir variable.

The other issue is passing all the existing command-line arguments to index.mjs unchanged. We do this with a combination of $@ (which refers to all the arguments passed to this script except the script name itself) and exec (which replaces the currently executing process with a new one - in this case it replaces the bash shell with node).

This approach let's us customise the CLI arguments, while still providing global access to our script. Here's an extract from xmppbridge's package.json showing how I specify that I want index.sh to be a global script:

{
    .....

    "bin": {
        "xmppbridge": "./index.sh"
    },

    .....
}

Bridging the Gap

Now that we've got Node calling our script correctly and the arguments parsed out, we can actually bridge the gap. This is as simple as some glue code between simple-xmpp and readline. simple-xmpp is an npm package that makes programmatic XMPP interaction fairly trivial (though I did have to look at examples in the GitHub repository to figure out how to send a message to a multi-user chatroom).

readline is a Node built-in that allows us to read the standard input line-by-line. It does other things too (and is great for interactive scripts amongst other things), but that's a tale for another time.

The first task is to create a new class for this to live in:

"use strict";

import readline from 'readline';

import xmpp from 'simple-xmpp';

class XmppBridge {

    /**
     * Creates a new XmppBridge instance.
     * @param   {string}    in_login_jid        The JID to login with.
     * @param   {string}    in_destination_jid  The JID to send stdin to.
     * @param   {Boolean}   in_is_groupchat     Whether the destination JID is a group chat or not.
     */
    constructor(in_destination_jid, in_is_groupchat) {
        // ....
    }
}

export default XmppBridge;

Very cool! That was easy. Next, we need to store those arguments and connect to the XMPP server in the constructor:

this.destination_jid = in_destination_jid;
this.is_destination_groupchat = in_is_groupchat;

this.client = xmpp;
this.client.on("online", this.on_connect.bind(this));
this.client.on("error", this.on_error.bind(this));
this.client.on("chat", ((_from, _message) => {
    // noop
}).bind(this));

I ended up having to define a chat event handler - even though it's pointless, as I ran into a nasty crash if I didn't do so (I suspect that this use-case wasn't considered by the original package developer).

The next area of interest is that online event handler. Note that I've bound the method to the current this context - this is important, as it would be able to access the class instance's properties otherwise. Let's take a look at the code for that handler:

console.log(`[XmppBridge] Connected as ${data.jid}.`);
if(this.is_destination_groupchat) {
    this.client.join(`${this.destination_jid}/bot_${data.jid.user}`);
}
this.stdin = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    terminal: false
});
this.stdin.on("line", this.on_line_handler.bind(this));
this.stdin.on("close", this.on_stdin_close_handler.bind(this));

This is the point at which we open the standard input and start listening for things to send. We don't do it earlier, as we don't want to end up in a situation where we try sending something before we're connected!

If we're supposed to be sending to a multi-user chatroom, this is also the point at which it joins said room. This is required as you can't send a message to a room that you haven't joined.

The resource (the bit after the forward slash /), for a group chat, specifies the nickname that you want to give to yourself when joining. Here, I automatically set this to the user part of the JID that we used to login prefixed with bot_.

The connection itself is established in the start method:

start(jid, password) {
    this.client.connect({
        jid,
        password
    });
}

And every time we receive a line of input, we execute the send() method:

on_line_handler(line_text) {
    this.send(line_text);
}

I used a full method here, as initially I had some issues and wanted to debug which methods were being called. That send method looks like this:

send(message) {
    this.client.send(
        this.destination_jid,
        message,
        this.is_destination_groupchat
    );
}

The last event handler worth mentioning is the close event handler on the readline interface:

on_stdin_close_handler() {
    this.client.disconnect();
}

This just disconnects from the XMXPP server so that Node can exit cleanly.

That basically completes the script. In total, the entire XmppBridge.mjs class file is 72 lines. Not bad going!

You can install this tool for yourself with sudo npm install -g xmppbridge. I've documented how it use it in the README, so I'd recommend heading over there if you're interested in trying it out.

Found this interesting? Got a cool use for XMPP? Comment below!

Sources and Further Reading

RhinoReminds: An XMPP reminder bot for my convenience

A Black Rhino from WikiMedia Commons. (Above: A Picture of a Black Rhino. Source: WikiMedia Commons)

Many times when I write a program it's to solve a problem. With Pepperminty Wiki, it was that I needed a lightweight wiki engine - and MediaWiki was just too complex. With TeleConsole, it was that I wanted to debug a C♯ Program in an environment that had neither a debugger nor a console (I'm talking about you, Unity 3D).

Today, I'm releasing RhinoReminds, an XMPP bot that reminds you about things. As you might have guessed, this is the end product of a few different posts I've made on here recently:

You can talk to it like so:

Remind me to water the greenhouse tomorrow at 4:03pm
Show all reminders
Delete reminders 2, 3, 4, and 7
Remind me in 1 hour to check the oven

...and it'll respond accordingly. It figures out which action to take based on the first word of the sentence you send it, but after that it uses AI (specifically Microsoft.Recognizers.Text, which I posted about here) to work out what you how you want it to do it.

I'm still working out a few bugs (namely reconnecting automagically after the connection to the server is lost, and ensuring all the messages it sends in reply actually make sense), but it's at the point now where it's stable enough that I can release it to everyone who'd either like to use it for themselves, or is simply curious :-)

If you'd like to run an instance of the bot for yourself, I recommend heading over to my personal git server here:

https://git.starbeamrainbowlabs.com/sbrl/RhinoReminds

The readme file should contain everything you need to know to get started. If not, let me know by contacting me, or commenting here!

Unfortunately, I'm not able to offer a public instance of this bot at the moment, due to concerns about spam. However, patches to improve the bots resistance against spammers (perhaps a cooldown period or something or too many messages are sent? or a limit of 50 active reminders per account?) are welcome.

Found this interesting? Got a cool use for it? Want help setting it up yourself? Comment below!

Write an XMPP bot in half an hour

Recently I've looked at using AI to extract key information from natural language, and creating a system service with systemd. The final piece of the puzzle is to write the bot itself - and that's what I'm posting about today.

Since not only do I use XMPP for instant messaging already but it's an open federated standard, I'll be building my bot on top of it for maximum flexibility.

To talk over XMPP programmatically, we're going to need library. Thankfully, I've located just such a library which appears to work well enough, called S22.XMPP. Especially nice is the comprehensive documentation that makes development go much more smoothly.

With our library in hand, let's begin! Our first order of business is to get some scaffolding in place to parse out the environment variables we'll need to login to an XMPP account.

using System;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

using S22.Xmpp;
using S22.Xmpp.Client;
using S22.Xmpp.Im;

namespace XmppBotDemo
{
    public static class MainClass
    {
        // Needed later
        private static XmppClient client;

        // Settings
        private static Jid ourJid = null;
        private static string password = null;

        public static int Main(string[] args)
        {
            // Read in the environment variables
            ourJid = new Jid(Environment.GetEnvironmentVariable("XMPP_JID"));
            password = Environment.GetEnvironmentVariable("XMPP_PASSWORD");

            // Ensure they are present
            if (ourJid == null || password == null) {
                Console.Error.WriteLine("XMPP Bot Demo");
                Console.Error.WriteLine("=============");
                Console.Error.WriteLine("");
                Console.Error.WriteLine("Usage:");
                Console.Error.WriteLine("    ./XmppBotDemo.exe");
                Console.Error.WriteLine("");
                Console.Error.WriteLine("Environment Variables:");
                Console.Error.WriteLine("    XMPP_JID         Required. Specifies the JID to login with.");
                Console.Error.WriteLine("    XMPP_PASSWORD    Required. Specifies the password to login with.");
                return 1;
            }

            // TODO: Connect here           

            return 0;
        }
    }
}

Excellent! We're reading in & parsing 2 environment variables: XMPP_JID (the username), and XMPP_PASSWORD. It's worth noting that you can call these environment variables anything you like! I chose those names as they describe their contents well. It's also worth mentioning that it's important to use environment variables for secrets passing them as command-line arguments cases them to be much more visible to other uses of the system!

Let's connect to the XMPP server with our newly read-in credentials:

// Create the client instance
client = new XmppClient(ourJid.Domain, ourJid.Node, password);

client.Error += errorHandler;
client.SubscriptionRequest += subscriptionRequestHandler;
client.Message += messageHandler;

client.Connect();

// Wait for a connection
while (!client.Connected)
    Thread.Sleep(100);

Console.WriteLine($"[Main] Connected as {ourJid}.");

// Wait forever.
Thread.Sleep(Timeout.Infinite);

// TODO: Automatically reconnect to the server when we get disconnected.

Cool! Here, we create a new instance of the XMPPClient class, and attach 3 event handlers, which we'll look at later. We then connect to the server, and then wait until it completes - and then write a message to the console. It looks like S22.Xmpp spins up a new thread, so unfortunately we can't catch any errors it throws with a traditional try-catch statement. Instead, we'll have to ensure we're really careful that we catch any exceptions we throw accidentally - otherwise we'll get disconnected!

It does appear that XmppClient catches some errors though, which trigger the Error event - so we should attach an event handler to that.

/// <summary>
/// Handles any errors thrown by the XMPP client engine.
/// </summary>
private static void errorHandler(object sender, ErrorEventArgs eventArgs) {
    Console.Error.WriteLine($"Error: {eventArgs.Reason}");
    Console.Error.WriteLine(eventArgs.Exception);
}

Before a remote contact is able to talk to our bot, they will send us a subscription request - which we'll need to either accept or reject. This is also done via an event handler. It's the SubscriptionRequest one this time:

/// <summary>
/// Handles requests to talk to us.
/// </summary>
/// <remarks>
/// Only allow people to talk to us if they are on the same domain we are.
/// You probably don't want this for production, but for developmental purposes
/// it offers some measure of protection.
/// </remarks>
/// <param name="from">The JID of the remote user who wants to talk to us.</param>
/// <returns>Whether we're going to allow the requester to talk to us or not.</returns>
public static bool subscriptionRequestHandler(Jid from) {
    Console.WriteLine($"[Handler/SubscriptionRequest] {from} is requesting access, I'm saying {(from.Domain == ourJid.Domain?"yes":"no")}");
    return from.Domain == ourJid.Domain;
}

This simply allows anyone on our own domain to talk to us. For development purposes this will offer us some measure of protection, but for production you should probably implement a whitelisting or logging system here.

The other interesting thing we can do here is send a user a chat message to either welcome them to the server, or explain why we rejected their request. To do this, we need to write a pair of utility methods, as sending chat messages with S22.Xmpp is somewhat over-complicated:

#region Message Senders

/// <summary>
/// Sends a chat message to the specified JID.
/// </summary>
/// <param name="to">The JID to send the message to.</param>
/// <param name="message">The messaage to send.</param>
private static void sendChatMessage(Jid to, string message)
{
    //Console.WriteLine($"[Bot/Send/Chat] Sending {message} -> {to}");
    client.SendMessage(
        to, message,
        null, null, MessageType.Chat
    );
}
/// <summary>
/// Sends a chat message in direct reply to a given incoming message.
/// </summary>
/// <param name="originalMessage">Original message.</param>
/// <param name="reply">Reply.</param>
private static void sendChatReply(Message originalMessage, string reply)
{
    //Console.WriteLine($"[Bot/Send/Reply] Sending {reply} -> {originalMessage.From}");
    client.SendMessage(
        originalMessage.From, reply,
        null, originalMessage.Thread, MessageType.Chat
    );
}

#endregion

The difference between these 2 methods is that one sends a reply directly to a message that we've received (like a threaded reply), and the other simply sends a message directly to another contact.

Now that we've got all of our ducks in a row, we can write the bot itself! This is done via the Message event handler. For this demo, we'll write a bot that echo any messages to it in reverse:

/// <summary>
/// Handles incoming messages.
/// </summary>
private static void messageHandler(object sender, MessageEventArgs eventArgs) {
    Console.WriteLine($"[Bot/Handler/Message] {eventArgs.Message.Body.Length} chars from {eventArgs.Jid}");
    char[] messageCharArray = eventArgs.Message.Body.ToCharArray();
    Array.Reverse(messageCharArray);
    sendChatReply(
        eventArgs.Message,
        new string(messageCharArray)
    );
}

Excellent! That's our bot complete. The full program is at the bottom of this post.

Of course, this is a starting point - not an ending point! A number of issues with this demo stand out. There isn't a whitelist, and putting the whole program in a single file doesn't sound like a good idea. The XMPP logic should probably be refactored out into a separate file, in order to keep the input settings parsing separate from the bot itself.

Other issues that probably need addressing include better error handling and more - but fixing them all here would complicate the example rather.

Edit: The code is also available in a git repository if you'd like to clone it down and play around with it :-)

Found this interesting? Got a cool use for it? Still confused? Comment below!

Complete Program

using System;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using S22.Xmpp;
using S22.Xmpp.Client;
using S22.Xmpp.Im;

namespace XmppBotDemo
{
    public static class MainClass
    {
        private static XmppClient client;
        private static Jid ourJid = null;
        private static string password = null;

        public static int Main(string[] args)
        {
            // Read in the environment variables
            ourJid = new Jid(Environment.GetEnvironmentVariable("XMPP_JID"));
            password = Environment.GetEnvironmentVariable("XMPP_PASSWORD");

            // Ensure they are present
            if (ourJid == null || password == null) {
                Console.Error.WriteLine("XMPP Bot Demo");
                Console.Error.WriteLine("=============");
                Console.Error.WriteLine("");
                Console.Error.WriteLine("Usage:");
                Console.Error.WriteLine("    ./XmppBotDemo.exe");
                Console.Error.WriteLine("");
                Console.Error.WriteLine("Environment Variables:");
                Console.Error.WriteLine("    XMPP_JID         Required. Specifies the JID to login with.");
                Console.Error.WriteLine("    XMPP_PASSWORD    Required. Specifies the password to login with.");
                return 1;
            }

            // Create the client instance
            client = new XmppClient(ourJid.Domain, ourJid.Node, password);

            client.Error += errorHandler;
            client.SubscriptionRequest += subscriptionRequestHandler;
            client.Message += messageHandler;

            client.Connect();

            // Wait for a connection
            while (!client.Connected)
                Thread.Sleep(100);

            Console.WriteLine($"[Main] Connected as {ourJid}.");

            // Wait forever.
            Thread.Sleep(Timeout.Infinite);

            // TODO: Automatically reconnect to the server when we get disconnected.

            return 0;
        }

        #region Event Handlers

        /// <summary>
        /// Handles requests to talk to us.
        /// </summary>
        /// <remarks>
        /// Only allow people to talk to us if they are on the same domain we are.
        /// You probably don't want this for production, but for developmental purposes
        /// it offers some measure of protection.
        /// </remarks>
        /// <param name="from">The JID of the remote user who wants to talk to us.</param>
        /// <returns>Whether we're going to allow the requester to talk to us or not.</returns>
        public static bool subscriptionRequestHandler(Jid from) {
            Console.WriteLine($"[Handler/SubscriptionRequest] {from} is requesting access, I'm saying {(from.Domain == ourJid.Domain?"yes":"no")}");
            return from.Domain == ourJid.Domain;
        }

        /// <summary>
        /// Handles incoming messages.
        /// </summary>
        private static void messageHandler(object sender, MessageEventArgs eventArgs) {
            Console.WriteLine($"[Handler/Message] {eventArgs.Message.Body.Length} chars from {eventArgs.Jid}");
            char[] messageCharArray = eventArgs.Message.Body.ToCharArray();
            Array.Reverse(messageCharArray);
            sendChatReply(
                eventArgs.Message,
                new string(messageCharArray)
            );
        }

        /// <summary>
        /// Handles any errors thrown by the XMPP client engine.
        /// </summary>
        private static void errorHandler(object sender, ErrorEventArgs eventArgs) {
            Console.Error.WriteLine($"Error: {eventArgs.Reason}");
            Console.Error.WriteLine(eventArgs.Exception);
        }

        #endregion

        #region Message Senders

        /// <summary>
        /// Sends a chat message to the specified JID.
        /// </summary>
        /// <param name="to">The JID to send the message to.</param>
        /// <param name="message">The messaage to send.</param>
        private static void sendChatMessage(Jid to, string message)
        {
            //Console.WriteLine($"[Rhino/Send/Chat] Sending {message} -> {to}");
            client.SendMessage(
                to, message,
                null, null, MessageType.Chat
            );
        }
        /// <summary>
        /// Sends a chat message in direct reply to a given incoming message.
        /// </summary>
        /// <param name="originalMessage">Original message.</param>
        /// <param name="reply">Reply.</param>
        private static void sendChatReply(Message originalMessage, string reply)
        {
            //Console.WriteLine($"[Rhino/Send/Reply] Sending {reply} -> {originalMessage.From}");
            client.SendMessage(
                originalMessage.From, reply,
                null, originalMessage.Thread, MessageType.Chat
            );
        }

        #endregion
    }
}

Jabber & XMPP: A Lost Protocol

Welcome to a special tutorial post here at starbeamrainbowlabs.com. In this post, we will be exploring an instant messaging protocol known as XMPP.

The XMPP logo

Today, you will probably use something like Skype, Gmail, or possibly FaceTime to stay in touch with your friends and family. If you were to rewind to roughly the year 2000, however, you would find that none of the above existed yet. Instead, there was something called XMPP. Originally called Jabber, XMPP is an open decentralised communications protocol (that Gmail's instant messaging service uses behind the scenes!) that allows you to stay in touch with people over the internet.

Identifying Users

There are several programs and apps that have XMPP support built in, but first let's take a look how it works. As I mentioned above, XMPP is decentralised. This means that there is no central point at which you can get an account - in fact you can create your very XMPP server right now! I will go into the details of that in a future post. Having multiple servers also raises the question of identification. How do you identify all these XMPP users at hundreds, possibly thousands of server across the globe?

Several account at 2 different servers

Thankfully, the answer is really quite simple: We use something called a Jabber ID (JID), which looks rather like an email address, for example: bob@bobsrockets.com. Just like an email address, the user name comes before the @ sign, and the server name comes after the @ sign.

Connecting People

Now that we know how you identify an XMPP user, we can look at how users connect and talk to each other, even if they have accounts at different servers. Connecting users is accomplished by 2 types of connections: client to server (c2s) and server to server (s2s) connections, which are usually carried out on ports 5222 and 5269 respectively. The client to server connections connect a user to their server that they registered with originally, and the server to server connections connect the user's server to the server that hosts the account to the other user that they want to talk to. In this way an XMPP user may start a conversation with any other XMPP user at any other server!

A visualisation of the example below

Here's an example. Bob is the owner of a company called Bob's Rockets and has the XMPP account bob@bobsrockets.com. He wants to talk to Bill, who owns the prestigious company Bill's Boosters who has the JID bill@billsboosters.com. Bob will log into his XMPP account at bobsrockets.com over port 5222 (unless he is behind a firewall, but we will cover that later). Bill will log into his account at billsboosters.com over the same port. When Bob starts a chat with Bill, the server at bobsrockets.com will automagically establish a new server to server connection with billsboosters.com in order to exchange messages.

Note: When starting a conversation with another user that you haven't talked to before, XMPP requires that both parties give permission to talk to one another. Depending on your client, you may see a box or notification appear somewhere, which you have to accept.

Get your own!

Now that we have taken a look at how it works, you probably want your own account. Getting one is simple: Just go to a site like jabber.org and sign up. If you stick around for the second post in this series though I will be showing you how to set up your very own XMPP server (with encryption).

As for a program or app you can use on your computer and / or your phone, I recommend Pidgin for computers and Xabber for Android phones.

Next time, I will be showing you how to set up your own XMPP server using Prosody. I will also be showing you a few of the add-ons you can plug in to add support for things like multi-user chatrooms (optionally with passwords), file transfer proxies, firewall-busting BOSH proxies, and more!

Art by Mythdael