Multilingual agents

Dialogflow supports many languages. For the complete list, see the languages reference page. The language you choose when creating an agent is set as the default language, and you can add additional languages.

Root and locale-specific languages

There are two categories of languages:

• Root languages: These are languages like English (en) that do not specify a locale.
• Locale-specific languages: These are languages like English-US (en-US) that do specify a locale as a specific region or country.

Some languages act as both root and locale-specific. There are significant differences between locales for these languages, so the locales cannot share a common root language. Examples:

• Chinese-Cantonese (zh-HK)
• Chinese-Simplified (zh-CN)
• Chinese-Traditional (zh-TW)
• Portuguese-Brazil (pt-BR)
• Portuguese-Portugal (pt)

You should primarily design your agent for root languages, and only customize for locale-specific languages as needed.

Add a language

Key Point: As a best practice, you should complete your agent in the default language before adding additional languages.

To add a language or locale with the Dialogflow Console:

1. Open the Dialogflow CX console.
2. Choose the Google Cloud project for the agent.
3. Find the agent in the list.
4. Click the agent display name.
5. Click Agent Settings.
6. Click the Languages tab.
7. Add or remove languages as needed.
8. Click Save.

Language-specific data

Note: The information in this section applies to both locale-specific and root languages. For example; en, en-US, and en-GB each have unique data for intent training phrases.

Most agent data is common for all languages of a multilingual agent. However, text used to interact with an end-user is language-specific. When building a multilingual agent, you must supply this language-specific data for each language. When you select a language from the console or provide a language to the API, you can access this language-specific data for the given language. The following is a complete list of language-specific data:

• intent training phrases
• fulfillment responses
• entity entries

To access language-specific data with the console, click the language button at the top of the console.

For example, the size entity type below is used for ordering t-shirts. The agent was originally configured in English, so the entity has entries like "S" with the synonym "small". When Spanish is added as a language, the entity is created by Dialogflow for the new language, but you need to supply entity entries in Spanish.

To access language-specific data with the API, provide the languageCode parameter when getting, creating, or updating EntityType, Intent, or Page types. Go to the EntityType API reference

Select a protocol and version for the EntityType reference:

Protocol	V3	V3beta1
REST	EntityType resource	EntityType resource
RPC	EntityType interface	EntityType interface
C++	EntityTypesClient	Not available
C#	EntityTypesClient	Not available
Go	EntityTypesClient	Not available
Java	EntityTypesClient	EntityTypesClient
Node.js	EntityTypesClient	EntityTypesClient
PHP	Not available	Not available
Python	EntityTypesClient	EntityTypesClient
Ruby	Not available	Not available

Close

Go to the Intent API reference

Select a protocol and version for the Intent reference:

Protocol	V3	V3beta1
REST	Intent resource	Intent resource
RPC	Intent interface	Intent interface
C++	IntentsClient	Not available
C#	IntentsClient	Not available
Go	IntentsClient	Not available
Java	IntentsClient	IntentsClient
Node.js	IntentsClient	IntentsClient
PHP	Not available	Not available
Python	IntentsClient	IntentsClient
Ruby	Not available	Not available

Close

Go to the Page API reference

Select a protocol and version for the Page reference:

Protocol	V3	V3beta1
REST	Page resource	Page resource
RPC	Page interface	Page interface
C++	PagesClient	Not available
C#	PagesClient	Not available
Go	PagesClient	Not available
Java	PagesClient	PagesClient
Node.js	PagesClient	PagesClient
PHP	Not available	Not available
Python	PagesClient	PagesClient
Ruby	Not available	Not available

Close

You must make separate API calls for each language to access all language-specific data. If your API calls update language-generic data, that data is updated for all languages.

Test in the simulator

When using the simulator, choose the language you want to use by selecting it below the agent name.

Supply a language using the API

When sending requests via the API, set the queryInput.languageCode field of the detectIntent method. For more information, see the Sessions type. Go to the Session API reference

Select a protocol and version for the Session reference:

Protocol	V3	V3beta1
REST	Session resource	Session resource
RPC	Session interface	Session interface
C++	SessionsClient	Not available
C#	SessionsClient	Not available
Go	SessionsClient	Not available
Java	SessionsClient	SessionsClient
Node.js	SessionsClient	SessionsClient
PHP	Not available	Not available
Python	SessionsClient	SessionsClient
Ruby	Not available	Not available

Close

Language auto detection

Note: This feature is available for chat conversations only.

Note: At the moment, language detection only supports identifying languages with major structural differences, and not variants of the same language. That means Dialogflow is able to differentiate among languages like ["en", "pt-br"], but not among variants of the same language like ["zh-tw", "zh-cn"] or ["pt", "pt-br"].

If the end-user's query language differs from the language specified in the request, Dialogflow can detect it and automatically switch to the end-user's language. See the language reference page for a list of languages available for this feature. The LanguageInfo field in a WebhookRequest identifies the input language, resolved language, and confidence score when language detection is enabled.

Enable language auto detection

You must enable language auto detection at both the agent and flow levels.

1. Go to Agent settings and select the Languages tab.

2. Check the box next to Enable language auto detection and switching to enable this feature for the agent. Click Save to save your changes.

3. Select a flow and navigate to Flow settings. In the flow settings panel, check the box next to Enable language auto detection and switching.

4. In the Languages drop-down menu, select the languages you want Dialogflow to be able to respond in. Make sure that you only select languages that are supported by the language auto detect feature.

5. Click Save to save your changes.

Requests that do not supply an agent's language

When Dialogflow receives a request that does not supply a language supported by the agent, the following rules apply:

• When a request does not supply a language, Dialogflow automatically determines the input language and responds in that language if automatic language detection is enabled. If automatic language detection is disabled, Dialogflow handles the request using the default language.
• When a request supplies a locale-specific language that is not supported by the agent, but the associated root language is supported by the agent, Dialogflow handles the request using the root language.
• System entity extraction is an exception to the previous rule. System entity extraction uses the supplied locale-specific language, even if the locale-specific language is not supported by the agent.

Integrations

Agent interactions through text-based integrations only use the default language of the agent.