The utter command takes an utterance ("play next song") and turns into a JSON payload, imitating as if it was coming from Alexa itself.

It works in a manner very similar to the Alexa simulator available via the Alexa developer console.

To start using it, you will need a local file that contains your Intent Schema and Sample Utterances.
By default, we have adopted the pattern used by the Alexa Skills Sample projects (see here).

That is, we look for the Interaction Model files inside a folder called speechAssets located off the source root.

You can specify an alternative location via options to the command-line.


To invoke the utter command, simply type:

$ bst utter <UTTERANCE>

For example:

$ bst utter Hello World

The utter command will return the full request and response of the interaction with your Skill service.

By default, the system will:

  • Use the Intent Model and Sample Utterances in the speechAssets folder under the current working directory
  • Use the service currently running via the bst proxy command

If no service is currently running via bst proxy, and HTTP endpoint can be specified with the --url option:

$ bst utter Hello World --url https://my.skill.com/skill/path

Speech Asset Format and Location

If your speech assets (Intent Model and Sample Utterances) are not stored under ./speechAssets, you can use an option to specify another location.

By default, we look for:

  • ./speechAssets/IntentSchema.json
  • ./speechAssets/SampleUtterances.txt


$ bst utter Hello World -i interactions/IntentSchema.json -s interactions/SampleUtterances.txt

The format of these files is the same as they are entered in the Alexa Skill configuration.

The Intent Schema is a JSON file. Samples utterances is a space-delimited text file.

An example of these files can be found here.

Working With Slots

Slot handling is a bit tricky. To send an utterance that uses slots, surround the slot variables like so:


For example, if the sample utterance was defined as:

HelloWorld Hello world, my name is {Name}

Then the utter command would be:

$ bst utter Hello World, my name is {John}

The value John will then be automatically placed in the Name slot for the utterance on the request.

Other Notes

Default Utterances

We currently use a simple algorithm to pick out a default Intent if none of the sample utterances match the supplied utterance.

This algorithm is - the first utterance of the first intent defined in the sample file.

This is meant to loosely mimic the behavior of the Alexa Simulator, which also seems to randomly select an intent/utterance when none matches.