Importing use PetalComponents brings the core component set into scope as unqualified function components (<.button>, <.modal>, <.table>, …).

The PetalComponents.Chat family (conversation, chat_message, markdown, tool_call, …) is intentionally not part of this import. It defines generically-named functions like markdown/1 that would clash with an app's own helpers, so you opt into it explicitly and call it namespaced:

alias PetalComponents.Chat

<Chat.conversation id="chat">
  <Chat.chat_message role="assistant"><Chat.markdown content={@text} /></Chat.chat_message>
</Chat.conversation>

See the streaming chat guide for the full setup.