Before trying this tutorial, you should be familiar with Dialogflow basics covered in Quickstarts.

Create an agent

Use the Dialogflow ES console to create an agent named "PackageTracker". If you are unsure how to do this, revisit the Quickstarts.

If you prefer to work with an existing agent, that is okay too. Just be sure that you enable auto speech adaptation in the agent settings. This is enabled by default for new agents.

Create a sequence recognizer entity

The core function of this agent is understanding alphanumeric sequences over voice. Specifically, you'll set up the agent to listen for a handful of characters at a time, eventually putting all sub-sequences together before validating the final sequence against a data store. Let's start by defining an entity to recognize the partial sequences.

Create the regexp sequence entities

We need to use a regexp entity to capture sequences so that auto speech adaptation will know to listen for "ABC" instead of "a bee sea".

These entities must conform to the auto speech adaptation regexp enitity guidelines to ensure the speech recognition is tuned to recognize spelled-out sequences.

Partial sequence entity

We'll set up the entity to accept any alphanumeric sequence of at least 3 characters. Later, you'll add a webhook so that you can validate the final sequence against a data store or API.

1. Create a new entity. We'll name it "alphanumeric" because it will accept any alphanumeric input.
2. Check the box for Regexp entity
3. Add a single entry, ^[a-zA-Z0-9]{3}[a-zA-Z0-9]*$
4. Click SAVE.

Notice that the regexp you added is very strict in that it is looking only for a string of alphanumerics, without any spaces or dashes. This is important for two reasons:

1. This regexp follows the auto speech adaptation requirements for enabling the "spelled-out sequence" recognizer mode.
2. By not looking for spaces and only looking for entire phrases (^...$), you allow end-users to easily exit the sequence recognition. For example, when you prompt "what's your order number" and an end-user replies "no I want to place an order", the regexp will reject and Dialogflow will know to look for another intent that might match that phrase.

If you are only interested in numeric values, you could create a more tailored entity like [0-9]{3}[0-9]*, or even just use the built-in @sys.number-sequence entity.

The rest of the tutorial assumes you are collecting alphanumeric sequences. Jump to the next section to see how to set up intents to collect these sequences.