Reading agent state

This example demonstrates reading from shared state in the CopilotKit Feature Viewer.

What is this?#

You can easily use the realtime agent state not only in the chat UI, but also in the native application UX.

When should I use this?#

You can use this when you want to provide the user with feedback about your agent's state. As your agent's state updates, you can reflect these updates natively in your application.

Implementation#

Run and connect your agent#

You'll need to run your agent and connect it to CopilotKit before proceeding. If you haven't done so already, you can follow the instructions in the Getting Started guide.

If you don't already have an agent, you can use the coagent starter as a starting point as this guide uses it as a starting point.

Setup your agent with state#

Define your agent's state schema. AWS Strands maintains state throughout execution.

agent/main.py

from ag_ui_strands import StrandsAgent, StrandsAgentConfig, create_strands_app
from strands import Agent
from strands.models.openai import OpenAIModel

model = OpenAIModel(
    client_args={"api_key": os.getenv("OPENAI_API_KEY", "")},
    model_id="gpt-4o",
)

# Create the Strands agent
strands_agent = Agent(
    model=model,
    system_prompt="Always communicate in the preferred language of the user as defined in your state. Do not communicate in any other language.",
)

# Inject state into the prompt
def language_prompt(input_data, user_message: str) -> str:
    state_dict = getattr(input_data, "state", None)
    if isinstance(state_dict, dict) and "language" in state_dict:
        return f"Current language: {state_dict['language']}\n\nUser request: {user_message}"
    return user_message

config = StrandsAgentConfig(state_context_builder=language_prompt)

# Wrap with AG-UI integration
agui_agent = StrandsAgent(
    agent=strands_agent,
    name="languageAgent",
    description="Always communicate in the preferred language of the user",
    config=config,
)

app = create_strands_app(agui_agent)

agent/main.ts

import { Agent } from "@strands-agents/sdk";
import { OpenAIModel } from "@strands-agents/sdk/models/openai";
import { StrandsAgent, type StrandsAgentConfig } from "@ag-ui/aws-strands";
import { createStrandsApp } from "@ag-ui/aws-strands/server";

const model = new OpenAIModel({
  apiKey: process.env.OPENAI_API_KEY ?? "",
  modelId: "gpt-4o",
});

// Create the Strands agent
const strandsAgent = new Agent({
  model,
  systemPrompt:
    "Always communicate in the preferred language of the user as defined in your state. Do not communicate in any other language.",
});

await strandsAgent.initialize();

// Inject state into the prompt
const config: StrandsAgentConfig = {
  stateContextBuilder: (inputData, userMessage) => {
    const state = (inputData.state ?? {}) as { language?: string };
    if (state.language) {
      return `Current language: ${state.language}\n\nUser request: ${userMessage}`;
    }
    return userMessage;
  },
};

// Wrap with AG-UI integration
const aguiAgent = new StrandsAgent({
  agent: strandsAgent,
  name: "languageAgent",
  description: "Always communicate in the preferred language of the user",
  config,
});

const app = await createStrandsApp(aguiAgent);
app.listen(8000);

Use the `useAgent` Hook#

With your agent connected and running, call the useAgent hook, wait for the real agent, and initialize any missing UI-owned state with agent.setState.

ui/app/page.tsx

import { useEffect } from "react";
import { useAgent } from "@copilotkit/react-core/v2";

// Define the agent state type to match your Strands agent
type AgentState = {
language: "english" | "spanish";
};

function YourMainContent() {
  const { agent, isReady } = useAgent({
    agentId: "strands_agent",
  });
  const state = (agent.state ?? {}) as Partial<AgentState>;

  useEffect(() => {
if (!isReady || state.language !== undefined) return;
    agent.setState({ ...(agent.state ?? {}), language: "spanish" });
  }, [agent, isReady, state.language]);

  // ...

  return (
    // style excluded for brevity
    <div>
      <h1>Your main content</h1>
      <p>Language: {state.language}</p>
    </div>
  );
}

The agent.state in useAgent is reactive and will automatically update when the agent state changes.

Give it a try!#

As the agent state updates, your state variable will automatically update with it! In this case, you'll see the language set to "spanish" after the connected agent is ready.

Rendering agent state in your app#

You can render the agent state in any React component under <CopilotKit>. Read agent.state and return ordinary JSX.