chat_ui: Create a chat UI element

In shinychat: Chat UI Component for 'shiny'

Create a chat UI element

Description

Inserts a chat UI element into a Shiny UI, which includes a scrollable section for displaying chat messages, and an input field for the user to enter new messages.

To respond to user input, listen for input$ID_user_input (for example, if id="my_chat", user input will be at input$my_chat_user_input), and use chat_append() to append messages to the chat.

Usage

chat_ui(
  id,
  ...,
  messages = NULL,
  placeholder = "Enter a message...",
  width = "min(680px, 100%)",
  height = "auto",
  fill = TRUE
)

Arguments

id	The ID of the chat element
...	Extra HTML attributes to include on the chat element
messages	A list of messages to prepopulate the chat with. Each message can be one of the following: A string, which is interpreted as markdown and rendered to HTML on the client. To prevent interpreting as markdown, mark the string as htmltools::HTML(). A UI element. This includes htmltools::tagList(), which take UI elements (including strings) as children. In this case, strings are still interpreted as markdown as long as they're not inside HTML. A named list of content and role. The content can contain content as described above, and the role can be "assistant" or "user".
placeholder	The placeholder text for the chat's user input field
width	The CSS width of the chat element
height	The CSS height of the chat element
fill	Whether the chat element should try to vertically fill its container, if the container is fillable

Value

A Shiny tag object, suitable for inclusion in a Shiny UI

Examples

library(shiny)
library(bslib)
library(shinychat)

ui <- page_fillable(
  chat_ui("chat", fill = TRUE)
)

server <- function(input, output, session) {
  observeEvent(input$chat_user_input, {
    # In a real app, this would call out to a chat model or API,
    # perhaps using the 'ellmer' package.
    response <- paste0(
      "You said:\n\n",
      "<blockquote>",
      htmltools::htmlEscape(input$chat_user_input),
      "</blockquote>"
    )
    chat_append("chat", response)
  })
}

shinyApp(ui, server)

shinychat documentation built on June 10, 2025, 9:09 a.m.