Changes in version 0.4.0.9000                      

                 Changes in version 0.4.0 (2026-06-01)                  

Experimental internal changes

  - The chat UI's rendering layer has been migrated from Lit to React.
    This significantly improves streaming performance — incoming chunks
    no longer clear previous DOM state — and makes the codebase more
    maintainable. One trade-off is that certain Shiny UI elements
    embedded in chat messages may not work as well as before (e.g.,
    inline <script> tags are generally not supported inside a React
    runtime). If you encounter issues, please let us know.

New features and improvements

  - The chat UI now displays model reasoning/thinking content as
    collapsible panels above assistant responses. Thinking content
    streams in real-time with animated topic labels. This works with
    providers that support structured thinking (e.g., Claude's extended
    thinking via ellmer) and with local models that wrap reasoning in
    <thinking> tags. (#208)

  - Added enable_cancel parameter to chat_ui() to show a stop button
    that lets users cancel an in-progress AI response. Press the stop
    button or hit Escape to cancel. chat_mod_ui() enables cancellation
    by default, and chat_mod_server() handles the cancellation wiring
    automatically, using the stream cancellation features introduced in
    ellmer v0.4.1. (#221)

  - Markdown lists where every item is a <span class="suggestion"> are
    now rendered as a grid of clickable suggestion cards. Each
    suggestion's text content becomes both the card label and the value
    sent on click. To add a short heading above the body text, set the
    title attribute on the span — e.g. <span class="suggestion"
    title="Heading">Body text shown on the card.</span>. Only the body
    text (not the title) is submitted when the card is clicked. Cards
    stream in with staggered animations and support keyboard navigation
    (arrow keys, Home/End) with roving tabindex. (#219)

  - Added chat_greeting() for creating welcome messages that appear when
    the chat is empty. Greetings can be set statically via
    chat_ui(greeting=) or dynamically from the server with
    chat_set_greeting(). They are automatically dismissed when the user
    sends their first message. A new greeting_requested input fires when
    the chat is visible, empty, and has no greeting, enabling
    LLM-generated welcome messages. chat_mod_server(greeting=) accepts a
    function for auto-generated greetings. (#217)

  - Tool result cards now render images and PDFs returned by ellmer
    tools. When a tool returns content_image_file(),
    content_image_url(), or content_pdf_file(), the result is displayed
    as an inline image or a PDF filename badge. Mixed content lists
    (e.g., list(ContentText("summary"), content_image_file("plot.png")))
    are rendered with items interleaved in order. (#225)

  - Added footer parameter to chat_ui() for displaying arbitrary HTML
    content below the chat input. Useful for disclaimers, attribution,
    or interactive toolbars. Styled with sensible defaults and
    customizable via --shiny-chat-footer-font-size and
    --shiny-chat-footer-color CSS custom properties. (#224)

  - Tool result cards now support a fullscreen toggle. Set full_screen =
    TRUE in the display list (or set res$full_screen <- NA in a custom
    contents_shinychat() method) to add a button that expands the card
    to fill the viewport. Press Escape, click the backdrop, or use the
    close button to exit fullscreen.

  - Added footer field to ToolResultDisplay for displaying custom HTML
    content below the tool result card body. (#178)

  - chat_mod_server() now returns a set_client(new_client, sync = TRUE)
    function for swapping the chat client used by the module at runtime.
    When sync = TRUE (the default), the new client inherits the current
    conversation's turns, system prompt, and tools so the conversation
    continues seamlessly. If a response is currently streaming, the swap
    is deferred until the stream completes. (#227)

  - chat_mod_server() now returns a status reactive that reports the
    current interaction state: "idle" when no response is in progress,
    or "streaming" while a response is actively being received. (#227)

  - chat_restore() now invisibly returns a cancel function that tears
    down all bookmark registrations made by that call. This is useful
    when swapping the chat client via set_client(), which handles the
    re-registration automatically. (#227)

Improvements

  - All navigating links in assistant messages now open in a new tab to
    preserve the app's session state. Cross-origin links still show the
    confirmation dialog; same-origin links open directly. (#238)

Bug fixes

  - Fixed the external link confirmation dialog not rendering in Safari.
    The backdrop overlay appeared but the dialog content was invisible
    due to a Bootstrap/<dialog> CSS interaction. (#201, #238)

  - Fixed pressing Escape to dismiss the external link dialog leaving it
    in a broken state where subsequent link clicks no longer worked.
    (#238)

  - Fixed an issue where user chat messages would display the default
    assistant icon. (#162)

                 Changes in version 0.3.0 (2025-11-20)                  

Breaking changes

  - chat_mod_server() now returns a list of reactives for last_input and
    last_turn, as well functions to update_user_input(), append() and
    clear() the chat. (#130, #143, #145)

New features

  - Added chat_restore() which adds Shiny bookmarking hooks to save and
    restore the {ellmer} chat client. (#28, #82)

  - Added update_chat_user_input() for programmatically updating the
    user input of a chat UI element. (#78)

  - shinychat now shows tool call request and results in the UI, and the
    feature is enabled by default in chat_app() and the chat module
    (chat_mod_server()). When using chat_append() with chat_ui(), set
    stream = "content" when you call the $stream_async() method on the
    ellmer::Chat client to ensure tool calls are included in the chat
    stream output. Learn more in the tool calling UI article. (#52)

  - Added chat_append(icon=...) and chat_ui(icon_assistant=...) for
    customizing the icon that appears next to assistant responses. (#88)

Improvements

  - chat_app() now correctly restores the chat client state when
    refreshing the app, e.g. by reloading the page. (#71)

  - External links in chat messages in chat_ui() now open in a new tab
    by default, with a confirmation dialog. (#120)

Bug fixes

  - The chat input no longer submits incomplete text when the user has
    activated IME completions (e.g. while typing in Japanese or
    Chinese). (#85)

Internal changes

  - We consolidated the <shiny-chat-message> and <shiny-user-message>
    components into a single <shiny-chat-message> component with a
    data-role attribute to indicate whether it's an "assistant" or
    "user" message. This likely has minimal impact on your apps, other
    than custom styles. You should update any shiny-user-message rules
    to use shiny-chat-message[data-role="user"]. (#101)

  - The chat UI's send input button is now identified by the class
    .shiny-chat-btn-send. (@DeepanshKhurana, #138)

                 Changes in version 0.2.0 (2025-05-16)                  

New features and improvements

  - Added new output_markdown_stream() and markdown_stream() functions
    to allow for streaming markdown content to the client. This is
    useful for showing Generative AI responses in real-time in a Shiny
    app, outside of a chat interface. (#23)

  - Both chat_ui() and output_markdown_stream() now support arbitrary
    Shiny UI elements inside of messages. This allows for gathering
    input from the user (e.g., selectInput()), displaying of rich output
    (e.g., {htmlwidgets} like {plotly}), and more. (#29)

  - Added a new chat_clear() function to clear the chat of all messages.
    (#25)

  - Added chat_app(), chat_mod_ui() and chat_mod_server(). chat_app()
    takes an {ellmer} chat client and launches a simple Shiny app
    interface with the chat. chat_mod_ui() and chat_mod_server()
    replicate the interface as a Shiny module, for easily adding a
    simple chat interface connected to a specific {ellmer} chat client.
    (#36)

  - The promise returned by chat_append() now resolves to the content
    streamed into the chat. (#49)

Bug fixes

  - chat_append(), chat_append_message() and chat_clear() now all work
    in Shiny modules without needing to namespace the id of the Chat
    component. (#37)

  - chat_append() now logs and throws a silent error if the stream
    errors for any reason. This prevents the app from crashing if the
    stream is interrupted. You can still use promises::catch() to handle
    the error in your app code if desired. (#46)

                 Changes in version 0.1.1 (2024-12-18)                  

  - Initial CRAN submission.