npm install @thesysai/genui-sdk@latest @crayonai/react-ui@latest @crayonai/react-core@latest @crayonai/stream@latest openai@latest next@latest react@^19.0.0 react-dom@^19.0.0

npx create-c1-app my-app
cd my-app
npm run dev

git clone https://github.com/thesysdev/template-c1-fastapi.git
cd template-c1-fastapi
pip install -r requirements.txt
uvicorn main:app --reload

Set your API key:
```bash
export THESYS_API_KEY=<your-api-key>

import { C1Component, ThemeProvider } from "@thesysai/genui-sdk";
import "@crayonai/react-ui/styles/index.css";

<ThemeProvider>
  <C1Component
    c1Response={response}
    isStreaming={isLoading}
    onAction={({ llmFriendlyMessage, humanFriendlyMessage }) => {
      // Handle button clicks, form submissions
    }}
    updateMessage={(updatedResponse) => {
      // Persist state changes to database
    }}
  />
</ThemeProvider>

import { C1Chat } from "@thesysai/genui-sdk";
import "@crayonai/react-ui/styles/index.css";

<C1Chat
  apiUrl="/api/chat"
  agentName="My Assistant"
  logoUrl="/logo.png"
  formFactor="full-page"  // or "side-panel"
/>

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.thesys.dev/v1/embed",
  apiKey: process.env.THESYS_API_KEY,
});

const response = await client.chat.completions.create({
  model: "c1/anthropic/claude-sonnet-4/v-20251230",
  messages: [
    { role: "system", content: "You are a helpful assistant." },
    { role: "user", content: "Show me a chart of sales data" }
  ],
  stream: true,
});

<thinking>Analyzing request...</thinking>
<content>
  <!-- Interactive UI components -->
</content>
<artifact id="report-1">
  <!-- Document content like slides/reports -->
</artifact>

npm install openai @crayonai/stream

// app/api/chat/messageStore.ts
import OpenAI from "openai";

export type DBMessage = OpenAI.Chat.ChatCompletionMessageParam & { id?: string };

const messagesStore: { [threadId: string]: DBMessage[] } = {};

export const getMessageStore = (threadId: string) => {
  if (!messagesStore[threadId]) {
    messagesStore[threadId] = [];
  }
  return {
    addMessage: (message: DBMessage) => {
      messagesStore[threadId].push(message);
    },
    getOpenAICompatibleMessageList: () => {
      return messagesStore[threadId].map((m) => {
        const { id, ...rest } = m;
        return rest;
      });
    },
  };
};

// app/api/chat/route.ts
import { NextRequest, NextResponse } from "next/server";
import OpenAI from "openai";
import { transformStream } from "@crayonai/stream";
import { DBMessage, getMessageStore } from "./messageStore";

export async function POST(req: NextRequest) {
  const { prompt, threadId, responseId } = await req.json() as {
    prompt: DBMessage;
    threadId: string;
    responseId: string;
  };

  const client = new OpenAI({
    baseURL: "https://api.thesys.dev/v1/embed",
    apiKey: process.env.THESYS_API_KEY,
  });

  const messageStore = getMessageStore(threadId);
  messageStore.addMessage(prompt);

  const llmStream = await client.chat.completions.create({
    model: "c1/anthropic/claude-sonnet-4/v-20251230",
    messages: messageStore.getOpenAICompatibleMessageList(),
    stream: true,
  });

  const responseStream = transformStream(
    llmStream,
    (chunk) => chunk.choices[0].delta.content,
    {
      onEnd: ({ accumulated }) => {
        const message = accumulated.filter(Boolean).join("");
        messageStore.addMessage({
          role: "assistant",
          content: message,
          id: responseId,
        });
      },
    }
  ) as ReadableStream;

  return new NextResponse(responseStream, {
    headers: {
      "Content-Type": "text/event-stream",
      "Cache-Control": "no-cache, no-transform",
      Connection: "keep-alive",
    },
  });
}

const client = new OpenAI({
  baseURL: "https://api.thesys.dev/v1/embed",  // Change from OpenAI
  apiKey: process.env.THESYS_API_KEY,
});

// Use existing tools and system prompts
const response = await client.beta.chat.completions.runTools({
  model: "c1/anthropic/claude-sonnet-4/v-20251230",
  messages: [...],
  tools: existingTools,
  stream: true,
});

// 1. Get text from your LLM
const textResponse = await yourLLM.generate(prompt);

// 2. Visualize with C1
const uiResponse = await c1Client.chat.completions.create({
  model: "c1/anthropic/claude-sonnet-4/v-20251230",
  messages: [{ role: "user", content: textResponse }],
});

const tools = [{
  type: "function",
  function: {
    name: "generate_ui",
    description: "Generate interactive UI for user",
    parameters: {
      type: "object",
      properties: {
        content: { type: "string", description: "Content to visualize" }
      }
    }
  }
}];