How to create a standard Jasper module

Augmenting Jasper with a new module is a fairly simple process. With just a few lines of code, you can have Jasper telling you the weather, sending you the top headlines, etc.

Getting Started

In this tutorial, we’ll use the ‘Meaning of Life’ ( module as an example. Pretend this module doesn’t exist and we want to implement it.

The basic functionality: You ask Jasper about the meaning of life, and he responds with some variation on “It’s 42.”

Here are the questions we need to answer in our implementation:

  • What keywords do we need to recognize in the user’s speech?
  • What does valid input to this module look like?
  • What do we do with valid input?

We’ll go through them in order.

What keywords do we need to recognize?

At this level, we’re thinking about words we need to detect in the user’s speech: that is, what words does the speech-to-text system need to be able to identify when the user speaks into the microphone?

As previously mentioned, we keep the speech-to-text dictionary small to improve accuracy, so we ask that every module makes public the exact words it will need to detect from speech input.

In terms of code, the interface requests a list of single-word strings called WORDS that sits in the module’s global namespace. For, we have the following:


If your module doesn’t require any keywords, assign WORDS = [], as the presence of the WORDS attribute is often used to determine whether a module is a Jasper module.

What does valid input look like?

At this level, we’re thinking about the translated text that the module will interpret: that is, once the speech-to-text system has done its work, what valid text inputs will this module accept?

In terms of code, the interface requests a method isValid(input) that returns True if the input is valid for this module, and False otherwise.

For, we just want the user input to contain some variation of “meaning of life”, such as “What’s the meaning of life?” or “Tell me the meaning of life”, which we accomplish as follows:

def isValid(text):
    return bool('\bmeaning of life\b', text, re.IGNORECASE))

Any word used in the isValid method should be included in the WORDS dictionary. How can you detect a word if the speech-to-text system never identifies it?

What do we do with valid input?

This is the heart of the module: you know you’ve been passed valid input, so what do you do next? The interface requires a method handle(input, mic, profile), where input is the parsed speech, mic is the mic object (used for speaking and taking in additional user input), and profile is the user profile.

In, we simply spout out a response:

def handle(text, mic, profile):
    messages = ["It's 42, you idiot.",
                "It's 42. How many times do I have to tell you?"]

    message = random.choice(messages)


The handle method will typically make active use of the user input (i.e., text), as in the following example.

What if user input is accepted by multiple modules?

This is a valid concern. Say you have both the ‘News’ and ‘Hacker News’ modules installed on your Jasper device, and the user input is “What’s on Hacker News?”. The ‘News’ module accepts any input with the (case-insensitive) string “news” in it; the ‘Hacker News’ module accepts any input with the (case-insensitive) string “hacker news” in it. So both would accept this input; but running more than one module is somewhat nonsensical. Which gets priority?

The more reasonable choice would be to pass it to the ‘Hacker News’ module. Why? It has more specific requirements on accepting user input and will trigger fewer false positives. The key idea, then, is to give a higher ‘priority’ to modules that accept more specific user input.

Modules can thus define an optional attribute PRIORITY, which should be an integer. Priorities work like CSS z-indices: their absolute value is meaningless, as modules are merely sorted by their priorities.

In the above example, the ‘Hacker News’ module defines PRIORITY = 4, while the ‘News’ module defines PRIORITY = 3. So if we’re passed in “What’s on Hacker News?”, the ‘Hacker News’ module will be checked first and will subsequently be passed in the input.

If a module does not define a PRIORITY, it will be defaulted to 0. Note that the ‘Unclear’ module has PRIORITY equal to Python’s smallest possible integer.

User Interaction

Some modules require user interaction. For example, in the News module (, we ask the user if they want to be emailed links to the top headlines.

In such cases, these methods will come in handy:

  1. mic.say(message): reads out message to the user.
  2. mic.activeListen(): beeps (to alert the user that input is required) and listens until the user has finished speaking, returning the parsed speech.

mic.activeListen() has a few optional arguments, but the default settings are sufficient for most use-cases.


All modules have complete access to profile, the user’s profile. This allows you to send texts or emails, read out timezone-sensitive dates, etc. The profile is simply a dictionary (see the Profile Guide for more).

A good example of using the user profile can be found in, where we take note of the user’s timezone when reading off the time:

def handle(text, mic, profile):
    user_tz = getTimezone(profile)
    now =
    response = now.strftime("%I:%M %p")
    mic.say("It is %s right now." % (response))

The profile is also useful for accessing permissions tokens, passwords, and more. In, we grab the user’s Facebook permissions token from the profile in order to find out their friends’ birthdays:

def handle(text, mic, profile):
    oauth_access_token = profile['keys']["FB_TOKEN"]

Of course, as the profile is just a dictionary, it can be extended in whatever way you’d like.

Finishing Steps

Jasper will automatically detect your module on restart and begin to respond to the user inputs you defined as valid in isValid(text).

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