BUILD A MESSENGER BOT

A part of Hack the Castle 2018

About Cetrez

Cetrez is a digital innovation company.

We exist to accelerate our clients’ advantage in their digital journey.

Hack The Castle

Part of Cetrez Academy

hack.cetrez.com

Todays agenda

• Getting started with bot development
• What makes a bot good
  • Common patterns and gotchas
• Make your bot smarter with NLP/NLU AI

Getting started

• Messenger Platform
  • Step by step Wizard
• Set up a page
  • Unpublished for testing
• Test out the node example

Local tunnel

Handle the frequent crashes

#!/usr/bin/env sh

DEFAULT_DOMAIN="$USER-$HOSTNAME"
SUBDOMAIN="${1:-$DEFAULT_DOMAIN}"
# Only lower case alpha numeric characters 
# are allowed for lt
SUBDOMAIN=$(echo $SUBDOMAIN | \
    tr '[:upper:]' '[:lower:]' | \
    tr -cd '[[:alnum:]]')

until lt --port 5000 --subdomain $SUBDOMAIN
do
    echo "# Restarting tunnel #"
    # Avoid restarts from flooding the CPU
    sleep 0.5
done

Start building

• Use the language of your choosing
  • Python for us
• Flask based library FBMQ
• Example server quick start
  • default.json ⇒ config.py

CONFIG = {
    'FACEBOOK_TOKEN': 'pageAccessToken',
    'VERIFY_TOKEN': 'validationToken',
    'SERVER_URL': 'https://sub.localtunnel.me'
}

{
    "appSecret": "…",
    "pageAccessToken": "…",
    "validationToken": "…",
    "serverURL": "https://sub.localtunnel.me"
}

Stupid bot

• Requires exact matches
  • Annoying!
• Levenshtein distance
  • Built into Python
  • Rough matches
• Fuzzy matching
  • Partial string similarity
  • Out of order tokens

Getting fuzzy

• Don't reinvent the wheel
• Fuzzy Wuzzy

from fuzzywuzzy import fuzz, process

# …

process.extractOne(
    text, 
    special_keywords.keys()
)

Be a nice bot

Make your bot's chat interface feel more natural, don't confuse your user.

Exemplar: Kilian Valkhof ​
A Messenger Adventure 
Game loop

6 things I learned

• People send stickers
• Users answer rhetorical questions
• No delay feels mechanical
• Use Quick replies
• Set up a Dev bot
• Get the Facebook Pages app

Delays

Natural delays make gives your bot depth

• Use typing indicators and read receipts 
• Split replies
• 30 ms / letter + random
  • Base delay on previous message if multiple

Use quick replys

Guide the user towards known functions

• Enhances discoverability
• Less confusion
• Traceable 

Stickers

Your users will send stickers to your bot

• Handle them as replies
• Different sizes have their own ID
  • Three sizes

Templates

Use templates to enable richer content replies

• Receipt
• Airline
  • Boarding passes
• Media
• Button
  • HTML, Phone, Buy
• List
  • 2-4 items
• Generic
  • Carousel

AI

Train your own models

• Rasa.ai

NLP/NLU as a Service

• Dialogflow (prev. API.ai)
  • By Google
• wit.ai
• ChatFuel
  • Graphical bot editor
• Watson Conversation

rasa.ai

wit.ai

Chatfuel

hack.cetrez.com