[kube]

Summary

Adds an assistant contribution to the plugin API. A plugin renders any React content in the AI assistant panel and fills its title bar, and the editor owns the panel's frame, placement, resizing, dock toggle and Close.

Editor shows the first running plugin that provides an assistant, and the aiAssistant prop's built-in chat while none runs. Built-in chat does not change, and the empty-net prompt also serves a plugin assistant that takes it. aiAssistant prop and the built-in chat's API are marked deprecated. Replaces #9914.

Before

<Petrinaut handle={handle} aiAssistant={{ transport, messages, onMessages }} />

With a second tab, the built-in chat drew both tabs:

<Petrinaut
  handle={handle}
  aiAssistant={{
    transport,
    primaryLabel: "Chat",
    additionalTab: { label: "Ledger", content: <LedgerPane /> },
  }}
/>

After

The chat lives in the plugin's hook, so onPrompt can send the empty-net prompt's message to it:

import { Chat, useChat } from "@ai-sdk/react";
import { AssistantPanelTitle, definePetrinautPlugin, type PluginHook } from "@hashintel/petrinaut/ui/plugin";
import type { UIMessage } from "ai";

const ChatPlugin = definePetrinautPlugin({ id: "example.chat", name: "Chat", assistant: true });

const ChatPanel = ({ chat }: { chat: Chat<UIMessage> }) => {
  const { messages, setMessages } = useChat({ chat });

  return (
    <>
      <AssistantPanelTitle
        actions={
          messages.length > 0 && (
            <button type="button" onClick={() => setMessages([])}>
              Clear
            </button>
          )
        }
      >
        Chat
      </AssistantPanelTitle>
      <MyChat chat={chat} />
    </>
  );
};

const useChatPlugin: PluginHook<typeof ChatPlugin> = () => {
  const [chat] = useState(() => new Chat({ transport }));

  return {
    assistant: {
      content: <ChatPanel chat={chat} />,
      onPrompt: (text) => chat.sendMessage({ text }),
    },
  };
};

export const chatPlugin = ChatPlugin(useChatPlugin);

<Petrinaut handle={handle} plugins={[chatPlugin]} />

With a second tab, the content draws its own tabs in the title bar:

const ChatPanel = ({ chat }: { chat: Chat<UIMessage> }) => {
  const [tab, setTab] = useState<"chat" | "ledger">("chat");

  return (
    <>
      <AssistantPanelTitle>
        <button type="button" onClick={() => setTab("chat")}>Chat</button>
        <button type="button" onClick={() => setTab("ledger")}>Ledger</button>
      </AssistantPanelTitle>
      {tab === "chat" ? <MyChat chat={chat} /> : <LedgerPane />}
    </>
  );
};

Links

• Ticket FE-2039
• Docs Writing a plugin › Provide the AI assistant
• Docs Plugin API reference

Changes

Plugin API

• Manifest assistant: true lets a plugin provide the AI assistant

  Its hook returns assistant: { content }.
  Editor shows the first running plugin that declares one, and the aiAssistant prop's chat while none runs.

• content fills the panel below its title bar

  It renders behind the plugin's error boundary and remounts when another net opens.

• AssistantPanelTitle fills the title bar from inside content

  children render after the assistant icon, such as a title or tabs.
  actions render between the dock toggle and the Close button.

• useAssistantPanel() reads whether the panel is open and closes it
• assistant.onPrompt(text) takes the empty-net prompt's message

  Editor opens the panel, then calls it.
  Prompt shows while the assistant returns onPrompt, or while the built-in chat runs.

• data-autofocus marks the element that takes focus when the panel opens

  Usually the composer. Without one, the panel takes focus.

• aiAssistant prop and the built-in chat's API are deprecated

  Every PetrinautAi* type, definePetrinautAiInteractiveTool, executePetrinautAiMutation, ExperimentExecutionCard and the DefaultChatTransport re-export carry @deprecated.
  So do the built-in chat's entry components.
  Each tag names the replacement, a plugin that declares assistant.

Editor

• Plugin assistants render in a panel frame of their own

  Frame holds the dock spacer, docked and floating placement, resizing, the card and the title bar with the dock toggle and Close.

• Plugins section tags a plugin that provides the assistant with Assistant

Test coverage

• editor-assistant.test.tsx:

  Plugin content and title bar in the panel, focus on open, Close from the title bar, and a failing content that keeps the panel's frame.

• editor-view.test.tsx:

  Empty-net prompt hands its message to onPrompt and opens the panel, and stays hidden for an assistant without one.

• define-petrinaut-plugin.test.ts:

  Type test: the hook returns assistant exactly when the manifest declares it.

• Existing @hashintel/petrinaut and website unit suites:

  Run the built-in chat as on main.

How to test

• Open Petrinaut preview on Vercel
• Menu > New
• Submit Build an SIR model in prompt

  Expect built-in chat open and net built

• Float AI assistant
• Dock AI assistant
• Close AI assistant
• Press ⌘⇧K

  Expect the same conversation and focus in composer

[vercel]

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Project	Deployment	Actions	Updated
petrinaut	Ready	Preview	Oct 21, 2026 11:44am UTC
petrinaut-docs	Ready	Preview	Oct 21, 2026 11:44am UTC

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[cursor]

PR Summary

Medium Risk
Changes how the AI assistant is integrated and deprecates a large public API, but keeps the built-in chat as fallback when no plugin provides an assistant.

Overview
Plugins can own the AI assistant panel instead of relying on the built-in chat behind the aiAssistant prop. Manifest assistant: true and hook contributions { content, onPrompt? } let the first running assistant plugin render chat UI below a shared shell (dock/float, resize, title bar slots) via AssistantPanelTitle and useAssistantPanel().

Editor wiring chooses plugin vs built-in through useEditorAssistant: when a plugin assistant runs, the aiAssistant prop is ignored; the empty-net prompt calls onPrompt when provided. The built-in AiAssistantPanel and the surrounding PetrinautAi* / voice / interactive-tool APIs are marked deprecated, with DefaultChatTransport re-exported from a local shim. Docs and tests cover the new plugin flow, panel focus/data-autofocus, and error boundaries at place: "assistant".

^{Reviewed by Cursor Bugbot for commit 33b5cc7. Bugbot is set up for automated code reviews on this repo. Configure here.}