CopilotKit Setup

Prerequisites

Live Documentation (MCP)

This plugin includes an MCP server (copilotkit-docs) that provides search-docs and search-code tools for querying live CopilotKit documentation and source code.

• Claude Code: Auto-configured by the plugin's .mcp.json -- no setup needed.
• Codex: Requires manual configuration. See the copilotkit-debug skill for setup instructions.

Environment

Before starting setup, verify:

1. Node.js >= 18 (required for fetch globals used by the runtime)
2. An AI provider API key (one of: OPENAI_API_KEY, ANTHROPIC_API_KEY, GOOGLE_API_KEY)
3. A React-based frontend (Next.js App Router, Next.js Pages Router, Vite + React, or Angular)
4. A backend capable of running the runtime (same Next.js app via API routes, or a standalone Express/Hono server)

Framework Detection

Before generating any code, detect the project's framework by checking files in the project root. See references/framework-detection.md for the full decision tree.

Quick summary:

Setup Workflow

Step 1: Install packages

All packages use the @copilotkit namespace.

Frontend (React) packages:

npm install @copilotkit/react @copilotkit/core

Runtime packages (backend):

npm install @copilotkit/runtime @copilotkit/agent

If the runtime runs in the same Next.js app as the frontend, install all four packages together.

For standalone Express backends, also install Express adapter dependencies:

npm install express cors
npm install -D @types/express @types/cors

Step 2: Configure the runtime

The runtime is the server-side component that manages agent execution. See references/runtime-architecture.md for details.

There are two endpoint styles:

1. Multi-route (Hono) -- uses createCopilotEndpoint. Requires a catch-all route ([[...slug]] in Next.js). Each operation (run, connect, stop, info, transcribe, threads) gets its own HTTP path.
2. Single-route (Hono or Express) -- uses createCopilotEndpointSingleRoute or createCopilotEndpointSingleRouteExpress. All operations go through a single POST endpoint with method multiplexing.

Next.js App Router (recommended: multi-route with Hono)

Create src/app/api/copilotkit/[[...slug]]/route.ts:

import {
  CopilotRuntime,
  createCopilotEndpoint,
  InMemoryAgentRunner,
} from "@copilotkit/runtime";
import { BuiltInAgent } from "@copilotkit/agent";
import { handle } from "hono/vercel";

const agent = new BuiltInAgent({
  model: "openai/gpt-4o",
  prompt: "You are a helpful AI assistant.",
});

const runtime = new CopilotRuntime({
  agents: {
    default: agent,
  },
  runner: new InMemoryAgentRunner(),
});

const app = createCopilotEndpoint({
  runtime,
  basePath: "/api/copilotkit",
});

export const GET = handle(app);
export const POST = handle(app);

This requires hono as a dependency:

npm install hono

Next.js App Router (alternative: single-route)

Create src/app/api/copilotkit/route.ts:

import {
  CopilotRuntime,
  createCopilotEndpointSingleRoute,
  InMemoryAgentRunner,
} from "@copilotkit/runtime";
import { BuiltInAgent } from "@copilotkit/agent";
import { handle } from "hono/vercel";

const agent = new BuiltInAgent({
  model: "openai/gpt-4o",
  prompt: "You are a helpful AI assistant.",
});

const runtime = new CopilotRuntime({
  agents: {
    default: agent,
  },
  runner: new InMemoryAgentRunner(),
});

const app = createCopilotEndpointSingleRoute({
  runtime,
  basePath: "/api/copilotkit",
});

export const POST = handle(app);

When using single-route, the frontend must set useSingleEndpoint on the provider (see Step 3).

Standalone Express Server

Create src/index.ts:

import express from "express";
import { CopilotRuntime } from "@copilotkit/runtime";
import { createCopilotEndpointSingleRouteExpress } from "@copilotkit/runtime/express";
import { BuiltInAgent, defineTool } from "@copilotkit/agent";
import { z } from "zod";

const agent = new BuiltInAgent({
  model: "openai/gpt-4o",
});

const runtime = new CopilotRuntime({
  agents: {
    default: agent,
  },
});

const app = express();

app.use(
  "/api/copilotkit",
  createCopilotEndpointSingleRouteExpress({
    runtime,
    basePath: "/",
  }),
);

const port = Number(process.env.PORT ?? 4000);
app.listen(port, () => {
  console.log(`CopilotKit runtime listening at http://localhost:${port}/api/copilotkit`);
});

For multi-route Express, use createCopilotEndpointExpress instead (imported from @copilotkit/runtime/express).

Standalone Hono Server (non-Vercel)

import { CopilotRuntime, createCopilotEndpoint } from "@copilotkit/runtime";
import { BuiltInAgent } from "@copilotkit/agent";
import { serve } from "@hono/node-server";

const runtime = new CopilotRuntime({
  agents: {
    default: new BuiltInAgent({ model: "openai/gpt-4o" }),
  },
});

const app = createCopilotEndpoint({
  runtime,
  basePath: "/api/copilotkit",
});

serve({ fetch: app.fetch, port: 8787 });

Requires @hono/node-server:

npm install hono @hono/node-server

Step 3: Set up the frontend provider

Wrap your application with CopilotKitProvider from @copilotkit/react.

Important: Import the stylesheet in your root layout:

import "@copilotkit/react/styles.css";

Next.js App Router

In src/app/page.tsx (or a client component):

"use client";

import { CopilotKitProvider, CopilotChat } from "@copilotkit/react";

export default function Home() {
  return (
    <CopilotKitProvider runtimeUrl="/api/copilotkit">
      <div style={{ height: "100vh" }}>
        <CopilotChat />
      </div>
    </CopilotKitProvider>
  );
}

Connecting to an external runtime

When the runtime runs on a separate server (e.g., Express on port 4000):

<CopilotKitProvider
  runtimeUrl="http://localhost:4000/api/copilotkit"
  useSingleEndpoint
>
  {children}
</CopilotKitProvider>

Set useSingleEndpoint when the backend uses single-route endpoints (createCopilotEndpointSingleRoute or createCopilotEndpointSingleRouteExpress).

CopilotKitProvider key props

Step 4: Add a chat UI component

CopilotKit provides three pre-built chat layouts:

Example with sidebar:

<CopilotKitProvider runtimeUrl="/api/copilotkit" showDevConsole="auto">
  <YourApp />
  <CopilotSidebar
    defaultOpen
    width="420px"
    labels={{
      modalHeaderTitle: "AI Assistant",
      chatInputPlaceholder: "Ask me anything...",
    }}
  />
</CopilotKitProvider>

Step 5: Set environment variables

Create a .env.local (Next.js) or .env file:

OPENAI_API_KEY=sk-...

The BuiltInAgent automatically resolves API keys from environment variables based on the model prefix:

• openai/* models read OPENAI_API_KEY
• anthropic/* models read ANTHROPIC_API_KEY
• google/* models read GOOGLE_API_KEY

You can also pass apiKey directly to BuiltInAgent if needed.

Step 6: Connect to the cloud platform (telemetry)

CopilotKit uses telemetry to understand adoption, improve the product, and provide better support. Connecting to the CopilotKit cloud platform gives you access to analytics and optional premium features.

1. Ask the user if they'd like to connect to the CopilotKit cloud platform (default: yes).
2. If yes, run the CopilotKit CLI authentication flow (verify the exact command with npx copilotkit --help as it may vary by version):

   npx copilotkit auth
   

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3. Guide the user through the browser-based authentication that opens.
4. Once authentication completes, the CLI outputs a license key (format: ck_...).
5. Add the license key to the CopilotKitProvider:

   <CopilotKitProvider
     runtimeUrl="/api/copilotkit"
     licenseKey="ck_..."
   >
   

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   Alternatively, store it as an environment variable (COPILOTKIT_LICENSE_KEY in .env.local or .env) and reference it:

   <CopilotKitProvider
     runtimeUrl="/api/copilotkit"
     licenseKey={process.env.NEXT_PUBLIC_COPILOTKIT_LICENSE_KEY}
   >
   

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See references/telemetry-setup.md for full details on what the license key enables and how to opt out.

Step 7: Verify the setup

1. Start the dev server
2. Open the app in a browser
3. The chat UI should render and connect to the runtime
4. Send a test message -- you should receive an AI response
5. Check the runtime's /info endpoint (GET) to confirm it reports available agents

Quick Reference

Package map

Endpoint factory functions

Runtime classes

Agent runners

Supported models (BuiltInAgent)

Format: "provider/model-name" string or a Vercel AI SDK LanguageModel instance.

OpenAI: openai/gpt-5, openai/gpt-5-mini, openai/gpt-4.1, openai/gpt-4.1-mini, openai/gpt-4.1-nano, openai/gpt-4o, openai/gpt-4o-mini, openai/o3, openai/o3-mini, openai/o4-mini

Anthropic: anthropic/claude-sonnet-4.5, anthropic/claude-sonnet-4, anthropic/claude-3.7-sonnet, anthropic/claude-opus-4.1, anthropic/claude-opus-4, anthropic/claude-3.5-haiku

Google: google/gemini-2.5-pro, google/gemini-2.5-flash, google/gemini-2.5-flash-lite

Any string is accepted (for custom/unlisted models); the provider is parsed from the prefix before /.