Prebuilt Components

Drop-in chat components with a full customization ladder, from pure CSS to fully headless.


"""LangGraph agent for the CopilotKit Showcase (FastAPI variant).Uses copilotkit's create_agent (wrapping langgraph) with CopilotKitMiddlewareso frontend-registered tools (useHumanInTheLoop, useFrontendTool) are properlyinjected into the LLM's tool list and executed on the frontend rather thanlocally."""from tools import (    get_weather_impl,    query_data_impl,    schedule_meeting_impl,    manage_sales_todos_impl,    get_sales_todos_impl,    search_flights_impl,    build_a2ui_operations_from_tool_call,)from tools.types import SalesTodo, Flightimport jsonimport timefrom typing import Anyfrom langchain_openai import ChatOpenAIfrom langchain_core.tools import tool as lc_toolfrom langchain_core.messages import SystemMessagefrom langchain.agents import AgentState as BaseAgentState, create_agentfrom langchain.tools import ToolRuntime, toolfrom langchain.messages import ToolMessagefrom langgraph.types import Commandfrom copilotkit import CopilotKitMiddlewareclass AgentState(BaseAgentState):    todos: list[SalesTodo]@lc_tooldef get_weather(location: str):    """Get the current weather for a location."""    return get_weather_impl(location)@lc_tooldef query_data(query: str):    """Query the database. Takes natural language. Always call before showing a chart."""    return query_data_impl(query)@lc_tooldef schedule_meeting(reason: str, duration_minutes: int = 30):    """Schedule a meeting. The user will be asked to pick a time via the UI."""    return schedule_meeting_impl(reason, duration_minutes)@lc_tooldef search_flights(flights: list[Flight]) -> str:    """Search for flights and display the results as rich cards. Return exactly 2 flights.    Each flight must have: airline, airlineLogo, flightNumber, origin, destination,    date (short readable format like "Tue, Mar 18" -- use near-future dates),    departureTime, arrivalTime, duration (e.g. "4h 25m"),    status (e.g. "On Time" or "Delayed"),    statusColor (hex color for status dot),    price (e.g. "$289"), and currency (e.g. "USD").    For airlineLogo use Google favicon API:    https://www.google.com/s2/favicons?domain={airline_domain}&sz=128    """    result = search_flights_impl(flights)    return json.dumps(result)@tooldef manage_sales_todos(todos: list[SalesTodo], runtime: ToolRuntime) -> Command:    """    Manage the current sales todos. Pass the full updated list.    """    updated = manage_sales_todos_impl(todos)    return Command(        update={            "todos": updated,            "messages": [                ToolMessage(                    content="Successfully updated sales todos",                    tool_call_id=runtime.tool_call_id,                )            ],        }    )@tooldef get_sales_todos(runtime: ToolRuntime):    """    Get the current sales todos.    """    current = runtime.state.get("todos", [])    return get_sales_todos_impl(current if current else None)@lc_tooldef render_a2ui(    surfaceId: str,    catalogId: str,    components: list[dict],    data: dict | None = None,) -> str:    """Render a dynamic A2UI v0.9 surface."""    return "rendered"@tool()def generate_a2ui(runtime: ToolRuntime[Any]) -> str:    """Generate dynamic A2UI components based on the conversation.    A secondary LLM designs the UI schema and data.    """    t0 = time.time()    messages = runtime.state["messages"][:-1]    context_entries = runtime.state.get("copilotkit", {}).get("context", [])    context_text = "\n\n".join(        entry.get("value", "")        for entry in context_entries        if isinstance(entry, dict) and entry.get("value")    )    model = ChatOpenAI(model="gpt-4.1")    model_with_tool = model.bind_tools([render_a2ui], tool_choice="render_a2ui")    response = model_with_tool.invoke(        [SystemMessage(content=context_text), *messages],    )    if not response.tool_calls:        return json.dumps({"error": "LLM did not call render_a2ui"})    args = response.tool_calls[0]["args"]    result = build_a2ui_operations_from_tool_call(args)    return json.dumps(result)model = ChatOpenAI(model="gpt-4o-mini")SYSTEM_PROMPT = """You are a polished, professional demo assistant for CopilotKit.Keep responses brief and clear -- 1 to 2 sentences max.You can:- Chat naturally with the user- Change the UI background when asked (via frontend tool)- Query data and render charts (via query_data tool)- Get weather information (via get_weather tool)- Schedule meetings with the user (via schedule_meeting tool -- the user picks a time in the UI)- Manage sales pipeline todos (via manage_sales_todos / get_sales_todos tools)- Search flights and display rich A2UI cards (via search_flights tool)- Generate dynamic A2UI dashboards from conversation context (via generate_a2ui tool)- Generate step-by-step plans for user review (human-in-the-loop)"""graph = create_agent(    model=model,    tools=[        get_weather,        query_data,        schedule_meeting,        search_flights,        generate_a2ui,        manage_sales_todos,        get_sales_todos,    ],    middleware=[CopilotKitMiddleware()],    state_schema=AgentState,    system_prompt=SYSTEM_PROMPT,)
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Pre-built components for agentic chat#

CopilotKit ships three prebuilt chat surfaces that connect directly to your agent: CopilotChat, CopilotSidebar, and CopilotPopup. Each is a wrapper around the same primitives with a different layout. Pick the one that fits your app; they all handle streaming, generative UI, and deep customization.

If your chat surface needs saved conversations, history, or thread switching, drop in the Threads Drawer next to any of them — or build your own switcher with Headless Threads.

The customization ladder#

One of CopilotKit's design principles is that you should never have to throw the prebuilt UI away to get the look you want. Start at the top of this ladder and step down only when you need more control.

Everything below Level 1 is incremental: you can freely mix CSS variables, a custom welcome slot, and headless tool-call renderers in the same app. Nothing forces you to throw work away as your needs grow.

Drop-in chat in a few lines#

Wrap your app in <CopilotKit> and drop <CopilotChat> where the chat should live. The provider wires the runtime, the session, and the agent registry. Everything else is optional configuration:

page.tsx
    <CopilotKit runtimeUrl="/api/copilotkit" agent="agentic_chat">      <Chat />    </CopilotKit>

Starter suggestions#

useConfigureSuggestions lets you seed the chat with contextual prompts the moment a user arrives. The example below uses a single "Write a sonnet" suggestion:

suggestions.ts
export function useAgenticChatSuggestions() {  useConfigureSuggestions({    suggestions: [      { title: "Write a sonnet", message: "Write a short sonnet about AI." },      {        title: "Tell me a joke",        message: "Tell me a one-line joke.",      },      {        title: "Is 17 prime?",        message: "Walk me through whether 17 is prime.",      },    ],    available: "always",  });}

Pick a surface#

Each surface is a drop-in component with the same underlying primitives, differing only in layout.

Add a conversation-history sidebar next to any of these with Threads Drawer — a drop-in thread switcher with no active-thread wiring.

Need to open/close the chat from your own button, or capture thumbs-up/down feedback? See Open, close, and feedback.