IMPORTANT: In July 2025, we stopped releasing new versions of KTX modules, and we removed the KTX libraries from the Firebase Android BoM (v34.0.0). If you use KTX APIs from the previously released KTX modules, we recommend that you migrate your app to use KTX APIs from the main modules instead. For details, see the FAQ about this initiative.

Chat

public final class Chat

Representation of a multi-turn interaction with a model.

Captures and stores the history of communication in memory, and provides it as context with each new message.

Note: This object is not thread-safe, and calling sendMessage multiple times without waiting for a response will throw an InvalidStateException.

Summary

Public fields
`final @NonNull List<@NonNull Content>`	`history` The previous content from the chat that has been successfully sent and received from the model.

Public constructors
`Chat(@NonNull GenerativeModel model, @NonNull List<@NonNull Content> history)`

Public methods
`final @NonNull GenerateContentResponse`	`sendMessage(@NonNull Bitmap prompt)` Sends a message using the existing history of this chat as context and the provided image prompt.
`final @NonNull GenerateContentResponse`	`sendMessage(@NonNull Content prompt)` Sends a message using the provided `prompt`; automatically providing the existing `history` as context.
`final @NonNull GenerateContentResponse`	`sendMessage(@NonNull String prompt)` Sends a message using the provided `text prompt`; automatically providing the existing `history` as context.
`final @NonNull Flow<@NonNull GenerateContentResponse>`	`sendMessageStream(@NonNull Bitmap prompt)` Sends a message using the existing history of this chat as context and the provided image prompt.
`final @NonNull Flow<@NonNull GenerateContentResponse>`	`sendMessageStream(@NonNull Content prompt)` Sends a message using the existing history of this chat as context and the provided `Content` prompt.
`final @NonNull Flow<@NonNull GenerateContentResponse>`	`sendMessageStream(@NonNull String prompt)` Sends a message using the existing history of this chat as context and the provided text prompt.

Public fields

history

public final @NonNull List<@NonNull Content> history

The previous content from the chat that has been successfully sent and received from the model. This will be provided to the model for each message sent (as context for the discussion).

Public constructors

Chat

public Chat(@NonNull GenerativeModel model, @NonNull List<@NonNull Content> history)

Parameters
`@NonNull GenerativeModel model`	The model to use for the interaction.

Public methods

sendMessage

public final @NonNull GenerateContentResponse sendMessage(@NonNull Bitmap prompt)

Sends a message using the existing history of this chat as context and the provided image prompt.

If successful, the message and response will be added to the history. If unsuccessful, history will remain unchanged.

Parameters
`@NonNull Bitmap prompt`	The input that, together with the history, will be given to the model as the prompt.

Throws
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if `prompt` is not coming from the 'user' role.
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if the `Chat` instance has an active request.

sendMessage

public final @NonNull GenerateContentResponse sendMessage(@NonNull Content prompt)

Sends a message using the provided prompt; automatically providing the existing history as context.

If successful, the message and response will be added to the history. If unsuccessful, history will remain unchanged.

Parameters
`@NonNull Content prompt`	The input that, together with the history, will be given to the model as the prompt.

Throws
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if `prompt` is not coming from the 'user' role.
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if the `Chat` instance has an active request.

sendMessage

public final @NonNull GenerateContentResponse sendMessage(@NonNull String prompt)

Sends a message using the provided text prompt; automatically providing the existing history as context.

If successful, the message and response will be added to the history. If unsuccessful, history will remain unchanged.

Parameters
`@NonNull String prompt`	The input that, together with the history, will be given to the model as the prompt.

Throws
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if `prompt` is not coming from the 'user' role.
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if the `Chat` instance has an active request.

sendMessageStream

public final @NonNull Flow<@NonNull GenerateContentResponse> sendMessageStream(@NonNull Bitmap prompt)

Sends a message using the existing history of this chat as context and the provided image prompt.

The response from the model is returned as a stream.

If successful, the message and response will be added to the history. If unsuccessful, history will remain unchanged.

Parameters
`@NonNull Bitmap prompt`	The input that, together with the history, will be given to the model as the prompt.

Throws
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if `prompt` is not coming from the 'user' role.
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if the `Chat` instance has an active request.

sendMessageStream

public final @NonNull Flow<@NonNull GenerateContentResponse> sendMessageStream(@NonNull Content prompt)

Sends a message using the existing history of this chat as context and the provided Content prompt.

The response from the model is returned as a stream.

If successful, the message and response will be added to the history. If unsuccessful, history will remain unchanged.

Parameters
`@NonNull Content prompt`	The input that, together with the history, will be given to the model as the prompt.

Throws
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if `prompt` is not coming from the 'user' role.
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if the `Chat` instance has an active request.

sendMessageStream

public final @NonNull Flow<@NonNull GenerateContentResponse> sendMessageStream(@NonNull String prompt)

Sends a message using the existing history of this chat as context and the provided text prompt.

The response from the model is returned as a stream.

If successful, the message and response will be added to the history. If unsuccessful, history will remain unchanged.

Parameters
`@NonNull String prompt`	The input(s) that, together with the history, will be given to the model as the prompt.

Throws
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if `prompt` is not coming from the 'user' role.
`com.google.firebase.ai.type.InvalidStateException com.google.firebase.ai.type.InvalidStateException`	if the `Chat` instance has an active request.