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This widget is and is subject to change in minor versions.
For more information, see Agent Studio.
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About this widget

<Chat> is a widget to display a chat interface that interacts with a generative AI assistant. See also: Agent Studio
<Chat> renders the chat panel but doesn’t provide a way to open it. Add one entry point to the same <InstantSearch> instance: the <ChatTrigger> widget, AI mode on a SearchBox or autocomplete, or an inline layout. Otherwise, the widget logs a development warning. To silence it, set disableTriggerValidation to true.

Examples

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Props

string
The unique identifier of the agent to connect to. You can find the agentId in the Agent Studio dashboard.
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boolean
Whether to enable feedback (thumbs up/down) on assistant messages. Only available when using agentId.
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object
Request options to send with the built-in Agent Studio completion requests. Use this option only with agentId. It isn’t available with a custom transport or custom chat instance.The object accepts the following properties:
  • queryParameters (Record<string, string | number | boolean>). Query parameters to append to each completion request.
  • headers (Record<string, string> | Headers). Headers to send with each completion request.
InstantSearch always keeps compatibilityMode=ai-sdk-5, even if you set compatibilityMode in queryParameters. Custom headers can’t override the required Algolia identity headers (x-algolia-application-id, x-algolia-api-key) or the x-algolia-agent header that identifies InstantSearch. When users regenerate an assistant message, InstantSearch sends cache=false even if requestOptions.queryParameters.cache is true.
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HttpChatTransportInitOptions
A custom transport object to handle the communication between the chat widget and the agent. The API endpoint must be compatible with Vercel AI SDK 5.
(nextUiState: object) => string
A function to return the URL of the main search page with the nextUiState. This is used to navigate to the main search page when the user clicks on “View all” in the search tool.
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Record<string, Tool>
An object defining the client-side tools that the agent can use to interact with your application. The object’s keys are tool names that must match the tools defined in the Agent Studio dashboard.The widget has built-in renderers for search and Display Results tools. Import and use the exported constants as keys to customize the default rendering:
  • SearchIndexToolType ('algolia_search_index'). Displays search results from an Algolia index in a carousel.
  • DisplayResultsToolType ('algolia_display_results'). Displays grouped results from the tool’s streaming input in carousels.
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To customize only the appearance of each result in the built-in carousel, use the itemComponent prop instead. To replace the whole carousel layout, override the SearchIndexToolType tool’s layoutComponent. The tool result is on message.output (hits, nbHits, queryID):
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For a step-by-step walkthrough, see Customize the chat results carousel.Each tool is an object with the following properties:
  • layoutComponent. A React component that renders the tool call in the chat. Receives the following props:
    • message. The tool call message. It contains input (parameters from the agent) and output (the result you provide with addToolResult). For more information on the message structure, see the Vercel AI SDK documentation.
    • indexUiState. The current InstantSearch UI state.
    • setIndexUiState. Updates the InstantSearch UI state (for example, to refine filters or update the query based on the tool call).
    • applyFilters. Applies filters to the InstantSearch UI state from the tool call.
    • addToolResult. Sends the tool’s output back to the agent. Call this at least once before the next message. For more information, see the Vercel AI SDK documentation.
    • onClose. Dismisses the tool’s UI in the chat.
    • sendEvent. Sends click or conversion events related to the tool call. For more information, see the insights middleware documentation.
  • onToolCall. Optional handler invoked when the agent calls the tool. Receives a parameter object with:
    • input. The parameters the agent passed to the tool.
    • addToolResult. Sends the tool’s output back to the agent. For more information, see the Vercel AI SDK documentation.
    • toolCallId. The unique identifier of the tool call.
    • toolName. The name of the tool being invoked.
    • dynamic. Whether the tool is dynamically registered.
  • streamInput. Optional boolean. When true, the default loader is suppressed as the tool’s input is streamed from the agent. Use the partial input in your layout template to render the streaming state as input chunks arrive.
Record<string, string> | () => Record<string, string>
Extra context to send with each user message (for example, the current page or selected locale). The widget sends this context with every message, but doesn’t show it in the chat UI.context can be a static object or a function that returns an object at send time. The widget attaches it to the latest user message as metadata.turnContext, following the Agent Studio per-turn context contract. The context never appears as a chat bubble.The context must be a flat object that maps strings to strings (up to 32 keys, 4,096 bytes total). Agent Studio validates the payload and rejects malformed contexts. For details, see Per-turn context.
The widget sends context to the agent in plain text. Don’t put secrets, access tokens, or personally identifiable information you don’t intend to share with the model in this field.
UIMessage[]
Messages to pre-populate the chat with when it’s initialized. These messages are added without triggering an AI response.initialMessages only applies when the chat has no existing messages. When resume is enabled, initialMessages is ignored.
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string
A message to send automatically when the chat is initialized.initialUserMessage is only sent when the chat has no existing messages. It’s sent after initialMessages are applied. When resume is enabled, this message isn’t sent.
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boolean
default:false
Whether to resume an ongoing chat generation stream when the widget mounts. Use this when restoring a chat session after a page reload to continue receiving an in-flight assistant response.
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boolean | { messages?: boolean; open?: boolean }
default:true
Whether to persist and restore the conversation and the open state of the chat panel from sessionStorage. When true (the default), the widget saves both the messages and whether the panel is open, and restores them when the widget re-mounts (for example, after a page reload). Set it to false to keep everything in memory only, so it’s cleared when the page reloads.To control each policy separately, pass an object with the messages and open booleans. Only what you set to true is persisted:
  • Omitted or true: persists the messages and the open state.
  • false or {}: persists nothing.
  • { messages: true }: persists the messages, but always starts with the panel closed.
  • { open: true }: persists the open state, but doesn’t persist messages.
With a custom chat instance, the instance owns message persistence, so only the open option is available. The open state is persisted by default: pass { open: false } to opt out.
boolean
default:false
Whether to skip the validation that requires a way to open the chat. By default, <Chat> logs a development warning unless the chat has an entry point: a <ChatTrigger> widget, AI mode on a SearchBox or autocomplete, or an inline layout. Set this to true when you open the chat programmatically and don’t render any of those.
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(options: { message, messages, isAbort, isDisconnect, isError }) => void
A callback called when the assistant response has finished streaming, including when the stream is aborted, disconnected, or fails.The callback receives an object with:
  • message: the final assistant message.
  • messages: the full message list including the new message.
  • isAbort: true if the stream was stopped with stop().
  • isDisconnect: true if the connection was lost.
  • isError: true if the stream finished with an error.
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(options: { messages: UIMessage[] }) => boolean | Promise<boolean>
A function that decides whether to resubmit the conversation to the agent without user input. It receives an object with messages, the current message list, and returns a boolean or a promise that resolves to one. When it returns true, <Chat> sends the conversation again so the agent can continue its turn.By default, <Chat> uses lastAssistantMessageIsCompleteWithToolCalls. It returns true when the last step of the last assistant message has at least one client-side tool call, and every one of those calls has an output or an error. This is what lets the agent act on the results of your tools and keep answering. The function ignores tool calls the agent executes on its own side, because their results don’t come from your app.<Chat> evaluates the function only for a response with at least one required client-side tool call. It waits for the response to finish streaming and for every required client-side tool call in that response to have a result, whichever comes last. It evaluates each response at most once, and skips a stream that’s stopped or fails.Return false to stop <Chat> from continuing turns on its own, for example when your tools end the turn and users send the next message.With a custom chat instance, set sendAutomaticallyWhen on the instance instead.
Whether the widget makes InstantSearch require a main search request. By default (true), the widget contributes to the main search. Set it to false to opt the widget out of the main search: if it’s the only widget on the page, no main search request is sent.
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boolean
default:false
Whether to display reasoning parts from assistant messages. Each reasoning part appears in a collapsed disclosure in its original message order. Users can expand or collapse each part, and the active part indicates that reasoning is still in progress.Copied assistant messages include the answer text, not the reasoning.
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(props: ChatEmptyProps) => JSX.Element
A component to customize the welcome screen shown before the first message, when the chat has no messages yet. Use it to display a greeting and starter prompts that send a message when clicked. It receives:
  • sendMessage. Sends a message to the agent. Call it with { text } to submit a starter prompt as the first message.
  • status. The current chat status.
  • onClose. Dismisses the chat.
  • setInput. Sets the value of the prompt input without sending it.
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To render the default greeting (heading, subheading, and an optional banner) inside your component, use the exported ChatGreeting component from react-instantsearch.For a step-by-step walkthrough, see Show starter prompts on the chat welcome screen.
(props: ChatLayoutOwnProps) => JSX.Element
A component to customize the overall layout of the chat widget. Use ChatInlineLayout for an inline (non-overlay) layout, ChatSidePanelLayout for a side panel on the right side of the page, or ChatOverlayLayout for the default floating overlay. To display a custom welcome screen before the first message, see Show starter prompts on the chat welcome screen.Use the side panel layout to keep the chat widget beside your page content on wider screens. Unlike the inline layout, the side panel requires an entry point to open the widget.By default, ChatSidePanelLayout adjusts document.body. Set its parentElement prop to a CSS selector to adjust another element.
  • When the side panel opens, the layout adds the value of --ais-chat-width to the selected element’s inline margin-right.
  • When the side panel closes, the layout restores the previous inline margin.
  • On wider screens, maximizing the chat widget changes the panel width to --ais-chat-maximized-width without increasing the reserved margin, so the maximized panel can overlap page content.
At viewport widths of 680px or less, the side panel fills the viewport. This breakpoint is based on the viewport width, not the width of parentElement.
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(props) => JSX.Element
A component to customize the loader shown while waiting for an AI response. Import the built-in ChatMessageLoader component from react-instantsearch to render the default loader, or provide your own component.
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To replace the loading state, see Customize the chat loading message.
() => JSX.Element
Components to customize the rendering of the widget.
  • itemComponent. Custom component for each result. Receives an object containing a single record.
  • headerCloseIconComponent. Header: close icon component.
  • headerMaximizeIconComponent. Header: maximize icon component. Receives a prop containing { maximized: boolean } for conditional rendering.
  • headerMinimizeIconComponent. Header: minimize icon component.
  • headerTitleIconComponent. Header: title icon component (defaults to sparkles).
  • messagesErrorComponent. Messages: custom error component. Guardrail fallback responses render as assistant messages, not through this component. By default, the widget shows a generic message (“Sorry, we are not able to generate a response at the moment. Please contact support.”) and a “Start a new conversation” button that clears the conversation. The component receives:
    • errorMessage. The raw error message from the API or transport layer.
    • onNewConversation. Callback that clears the conversation and starts a new one. Use it to render a “Start a new conversation” action for errors where retrying fails again.
  • assistantMessageLeadingComponent. Assistant message: custom leading component (e.g. avatar).
  • assistantMessageFooterComponent. Assistant message: custom footer component.
  • userMessageLeadingComponent. User message: custom leading component (e.g. avatar).
  • userMessageFooterComponent. User message: custom footer component.
  • promptFooterComponent. Prompt: custom footer component.
  • promptHeaderComponent. Prompt: custom header component.
  • suggestionsComponent. Custom component to render follow-up prompt suggestions. Receives a prop containing { suggestions: string[], onSuggestionClick: (str: string) => void }.
To customize the button that opens the chat, use the <ChatTrigger> widget’s toggleIconComponent prop instead.To add a disclaimer or policy notice, see Add a legal notice to the chat widget.
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object
Props forwarded to the messages section of the widget. Use assistantMessageProps and userMessageProps to customize each role separately:
  • textComponent. A component that renders each text part of the message. It replaces the default markdown rendering. It receives:
    • part. The text part to render. Its text property holds the text content.
    • message. The message the text part belongs to.
    • messages. The full conversation, when available.
    • status. The current chat status: 'ready', 'submitted', 'streaming', or 'error'.
    • partIndex. The index of the text part in the message’s parts array.
  • parseMarkdown. The default value is true. The widget renders text and reasoning parts as Markdown, including links, code blocks, and emphasis. Set parseMarkdown to false to render reasoning parts and text parts that use the default renderer as plain text. Line breaks are preserved and links aren’t clickable. Use this option for user messages when Markdown characters such as * or _ should remain literal. If you provide a textComponent, it takes precedence for text parts. parseMarkdown then only controls reasoning parts.
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To render user messages as plain text while keeping the default Markdown rendering for assistant messages:
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Partial<ChatClassNames>
The CSS classes you can override and pass to the widget’s elements. It’s useful to style widgets with class-based CSS frameworks like Bootstrap or Tailwind CSS.
  • root. The root element of the widget.
  • container. The container element.
  • header. The header section of the widget.
    • root. The root element.
    • clear. The clear button.
    • close. The close button.
    • maximize. The maximize button.
    • title. The title element.
    • titleIcon. The title icon element.
  • messages. The messages section of the widget.
    • root. The root element.
    • content. The scrollable content.
    • scroll. The scroll container.
    • scrollToBottom. The scroll to bottom button.
    • scrollToBottomHidden. The hidden state of the scroll to bottom button.
  • message. The message in the messages section.
    • root. The root element.
    • container. The message container.
    • leading. The leading element (e.g., avatar).
    • content. The content element.
    • message. The message text element.
    • reasoning. The reasoning disclosure.
    • reasoningHeader. The reasoning disclosure header.
    • reasoningIcon. The reasoning icon.
    • reasoningLabel. The reasoning label.
    • reasoningChevron. The reasoning disclosure chevron.
    • reasoningBody. The reasoning body.
    • reasoningText. The reasoning text.
    • actions. The action buttons container.
    • footer. The footer element.
  • prompt. The prompt section of the widget.
    • root. The root element.
    • actions. The actions container.
    • body. The body element.
    • footer. The footer element.
    • header. The header element.
    • submit. The submit button.
    • textarea. The textarea element.
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Partial<ChatTranslations>
A dictionary of translations to customize the UI text and support internationalization.
  • header. The header section of the widget.
    • clearLabel. Accessible label for the clear button.
    • closeLabel. Accessible label for the close button.
    • maximizeLabel. Accessible label for the maximize button.
    • minimizeLabel. Accessible label for the minimize button.
    • title. Title to display.
  • messages. The messages section of the widget.
    • copyToClipboardLabel. Accessible label for the copy to clipboard action.
    • feedbackThankYouText. Text shown after feedback is submitted (default: 'Thanks for your feedback!').
    • loaderText. Text to display in the loader.
    • regenerateLabel. Accessible label for the regenerate action.
    • scrollToBottomLabel. Accessible label for the scroll to bottom button.
    • sendingFeedbackLabel. Accessible label for the feedback spinner (default: 'Sending feedback...').
    • thumbsDownLabel. Accessible label for the thumbs down button (default: 'Dislike').
    • thumbsUpLabel. Accessible label for the thumbs up button (default: 'Like').
  • message. Individual message in the messages section.
    • messageLabel. Accessible label for the message.
    • actionsLabel. Accessible label for the actions container.
    • reasoningLabel. Label for a reasoning disclosure.
  • prompt. The prompt section of the widget.
    • disclaimer. Disclaimer text shown in the prompt footer.
    • emptyMessageTooltip. Tooltip for the submit button when message is empty.
    • sendMessageTooltip. Tooltip for the send button.
    • stopResponseTooltip. Tooltip for the stop button.
    • textareaLabel. Accessible label for the textarea.
    • textareaPlaceholder. Placeholder text for the textarea.
To add richer prompt or message notices, see Add a legal notice to the chat widget.
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React.ComponentProps<'div'>
Any <div> prop to forward to the root element of the widget.
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Streaming and resumption

Assistant responses stream over Server-Sent Events. The useChat hook exposes the streaming lifecycle if you want to drive a custom UI.

Status values

useChat returns a status value, which can be one of:
  • 'ready'. The chat is idle and ready to accept a new message.
  • 'submitted'. A user message was submitted and the assistant hasn’t started responding yet.
  • 'streaming'. The assistant is streaming a response.
  • 'error'. The last response finished with an error. Call clearError() before sending a new message.
Each message part also carries a state of 'streaming' or 'done' while the response streams.

Stop and resume

useChat also returns:
  • stop(). Aborts the current streaming response. The onFinish callback runs with isAbort: true.
  • resumeStream(). Reconnects to an in-flight stream. Call this on mount, or pass resume to <Chat> to do it automatically.
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To resume an ongoing stream after a reload, set resume on <Chat>, or call resumeStream() from a custom component.
Last modified on August 21, 2026