multivocal/docs/notes-dialogflow3.md

A node.js library to assist with building best practice, configuration driven, Actions for the Google Assistant.

# Dialogflow 3 (Dialogflow CX)

## Verification

Dialogflow sends a 
[service identity token](https://cloud.google.com/dialogflow/cx/docs/concept/webhook#id-token) 
in the HTTP "Authorization" header. The documentation references that this should be a 
[Google identity token](https://developers.google.com/identity/sign-in/web/backend-auth#verify-the-integrity-of-the-id-token),
however, it differs from the documented format in two significant ways:

* The "aud" field does not contain one of the client IDs. Instead, it contains
    the endpoint of the webhook.
* The "email" field contains an email address that includes the client ID.

The JWT validator does not try to validate the "email" field, but instead has
the webhook endpoint as one of the valid "aud" fields. If this doesn't match
for some reason, you may need to add it yourself in `Config/Setting/JWTAuth/Google/aud`.

## Locale

Dialogflow sends the language/locale information in a `languageCode` field in
the body, however this may either specify a language (without locale), or a 
language and locale where the locale is in lowercase letters.

In the latter case, Multivocal normalizes this to use uppercase letters.

## Integrations

The following integrations are detected:

* [dfMessenger](https://cloud.google.com/dialogflow/cx/docs/concept/integration/dialogflow-messenger)
* telephony
* generic (ie - everything else)

Note that the detection method is somewhat hacky, since Dialogflow does not
provide a standard way to get this information.

### Dialogflow Messenger (dfMessenger)

This assumes that the session ID begins with "dfMessenger-", which is what
the default generated ID uses.

RichMedia supported:

* Suggestion chips with `Msg/Suggesion` and `Suffix/Suggestion` arrays.
  Only the text is supported. Images and link-outs are not.

### Telephony

This has been tested with the [Diallogflow CX Phone Gateway](https://cloud.google.com/dialogflow/cx/docs/concept/integration/phone-gateway),
but may work for other telephony integrations. It relies on either a 
"telephony" payload or a "transcript" provided in the request.

Responses supported:

* SSML with the "outputAudioText" message. Although it isn't clear if the
  Dialogflow CX Phone Gateway supports this.