# Cloudflare Agents
[](https://www.npmjs.com/package/agents)
[](https://www.npmjs.com/package/agents)
Agents are persistent, stateful execution environments for agentic workloads, powered by Cloudflare [Durable Objects](https://developers.cloudflare.com/durable-objects/). Each agent has its own state, storage, and lifecycle — with built-in support for real-time communication, scheduling, AI model calls, MCP, workflows, and more.
Agents hibernate when idle and wake on demand. You can run millions of them — one per user, per session, per game room — each costs nothing when inactive.
```sh
npm create cloudflare@latest -- --template cloudflare/agents-starter
```
Or add to an existing project:
```sh
npm install agents
```
**[Read the docs](https://developers.cloudflare.com/agents/)** — getting started, API reference, guides, and more.
## Quick Example
A counter agent with persistent state, callable methods, and real-time sync to a React frontend:
```typescript
// server.ts
import { Agent, routeAgentRequest, callable } from "agents";
export type CounterState = { count: number };
export class CounterAgent extends Agent<Env, CounterState> {
initialState = { count: 0 };
@callable()
increment() {
this.setState({ count: this.state.count + 1 });
return this.state.count;
}
@callable()
decrement() {
this.setState({ count: this.state.count - 1 });
return this.state.count;
}
}
export default {
async fetch(request: Request, env: Env, ctx: ExecutionContext) {
return (
(await routeAgentRequest(request, env)) ??
new Response("Not found", { status: 404 })
);
}
};
```
```tsx
// client.tsx
import { useAgent } from "agents/react";
import { useState } from "react";
import type { CounterAgent, CounterState } from "./server";
function Counter() {
const [count, setCount] = useState(0);
const agent = useAgent<CounterAgent, CounterState>({
agent: "CounterAgent",
onStateUpdate: (state) => setCount(state.count)
});
return (
<div>
<span>{count}</span>
<button onClick={() => agent.stub.increment()}>+</button>
<button onClick={() => agent.stub.decrement()}>-</button>
</div>
);
}
```
State changes sync to all connected clients automatically. Call methods like they're local functions.
The agent is a Durable Object, so it needs a binding and a SQLite migration in `wrangler.jsonc`:
```jsonc
{
"name": "counter",
"main": "server.ts",
"compatibility_date": "2026-06-11",
"compatibility_flags": ["nodejs_compat"],
"durable_objects": {
"bindings": [{ "name": "CounterAgent", "class_name": "CounterAgent" }]
},
"migrations": [{ "tag": "v1", "new_sqlite_classes": ["CounterAgent"] }]
}
```
## Features
| Feature | Description |
| ----------------------- | ------------------------------------------------------------------------------- |
| **Persistent State** | Syncs to all connected clients, survives restarts |
| **Callable Methods** | Type-safe RPC via the `@callable()` decorator |
| **Sub-agents** | Parent/child DO composition via facets, nested routing, and typed parent lookup |
| **Agent Tools** | Run chat-capable sub-agents as tools with streaming child timelines |
| **Scheduling** | One-time, recurring, and cron-based tasks |
| **WebSockets** | Real-time bidirectional communication with lifecycle hooks |
| **AI Chat** | Message persistence, resumable streaming, server/client tool execution |
| **MCP** | Act as MCP servers or connect as MCP clients (HTTP, SSE, RPC, elicitation) |
| **WebMCP** | Expose page-local tools or bridge remote MCP tools to browser agents |
| **Workflows** | Durable multi-step tasks with human-in-the-loop approval |
| **Email** | Send, receive, and reply via Cloudflare Email Service |
| **Voice** | Continuous STT, streaming TTS, VAD, interruption, SFU utilities |
| **Browser Agents** | Run agents in the browser tab with `agents/browser` |
| **Code Mode** | LLMs generate executable TypeScript instead of individual tool calls |
| **Sandboxed Execution** | Run generated code inside an isolated Worker with a virtual filesystem |
| **x402 Payments** | Pay-per-call APIs and tools via the x402 protocol |
| **Observability** | Built-in tracing, metrics, and structured logs |
| **SQL** | Direct SQLite queries via Durable Objects |
| **React Hooks** | `useAgent`, `useAgentChat`, `useVoiceAgent` for frontend integration |
| **Vanilla JS Client** | `AgentClient` and `VoiceClient` for non-React environments |
## Packages
| Package | Description |
| ------------------------------------------------------- | --------------------------------------------------------------------------------------------- |
| [`agents`](packages/agents) | Core SDK — Agents, routing, Voice, Channels, scheduling, MCP, workflows, x402, browser agents |
| [`@cloudflare/ai-chat`](packages/ai-chat) | Higher-level AI chat — persistent messages, resumable streaming, tool execution |
| [`@cloudflare/think`](packages/think) | Opinionated chat agent base — agentic loop, stream resumption, client tools, workspace tools |
| [`@cloudflare/codemode`](packages/codemode) | LLMs write executable code that calls your tools, instead of one tool call at a time |
| [`@cloudflare/shell`](packages/shell) | Deprecated: use [`@cloudflare/computer`](https://github.com/cloudflare/computer) workspaces |
| [`@cloudflare/voice`](packages/voice) | Deprecated compatibility wrapper for the `agents/voice` exports |
| [`@cloudflare/worker-bundler`](packages/worker-bundler) | Build and bundle Workers at runtime, for use with the Worker Loader binding |
| [`hono-agents`](packages/hono-agents) | Hono middleware for adding agents to Hono apps |
> AI-chat modules used to live in `agents/ai-chat-agent`, `agents/chat`, `agents/ai-react`, and `agents/ai-types`. Those entry points still re-export, but they're deprecated — import from `@cloudflare/ai-chat` directly. New chat-from-scratch projects should look at `@cloudflare/think`.
## Examples
The [`examples/`](examples) directory has 30+ self-contained demos. A non-exhaustive tour:
- **Showcase** — [`playground/`](examples/playground) is the kitchen-sink app: state, callable methods, scheduling, chat, tools, MCP, workflows, email, voice — all in one UI
- **Chat & assistants** — [`assistant/`](examples/assistant), [`agents-as-tools/`](examples/agents-as-tools), [`agent-skills/`](examples/agent-skills), [`workspace-chat/`](examples/workspace-chat), [`resumable-stream-chat/`](examples/resumable-stream-chat), [`structured-input/`](examples/structured-input), [`dynamic-tools/`](examples/dynamic-tools), [`multi-ai-chat/`](examples/multi-ai-chat), [`context-overflow-recovery/`](examples/context-overflow-recovery)
- **MCP** — [`mcp/`](examples/mcp), [`mcp-client/`](examples/mcp-client), [`mcp-server/`](examples/mcp-server), [`mcp-worker/`](examples/mcp-worker), [`mcp-worker-authenticated/`](examples/mcp-worker-authenticated), [`mcp-elicitation-mrtr/`](examples/mcp-elicitation-mrtr), [`mcp-elicitation/`](examples/mcp-elicitation), [`mcp-rpc-transport/`](examples/mcp-rpc-transport), [`webmcp/`](examples/webmcp), [`webmcp-react/`](examples/webmcp-react)
- **Code Mode & sandboxes** — [`codemode/`](examples/codemode), [`codemode-mcp/`](examples/codemode-mcp), [`codemode-mcp-openapi/`](examples/codemode-mcp-openapi), [`dynamic-workers/`](examples/dynamic-workers), [`dynamic-workers-playground/`](examples/dynamic-workers-playground), [`worker-bundler-playground/`](examples/worker-bundler-playground)
- **Voice** — [`voice-agent/`](examples/voice-agent) is the unified voice pipeline example with Workers AI, AssemblyAI, Telnyx, and ElevenLabs STT; [`voice-input/`](examples/voice-input) covers dictation; [`telnyx-voice-agent/`](examples/telnyx-voice-agent) covers phone transport; [`elevenlabs-starter/`](examples/elevenlabs-starter) covers broader ElevenLabs media APIs
- **Workflows & approvals** — [`workflows/`](examples/workflows), [`a2a/`](examples/a2a)
- **Auth, payments, comms** — [`auth-agent/`](examples/auth-agent), [`cross-domain/`](examples/cross-domain), [`x402/`](examples/x402), [`x402-mcp/`](examples/x402-mcp), [`email-agent/`](examples/email-agent), [`github-webhook/`](examples/github-webhook), [`push-notifications/`](examples/push-notifications)
- **Game & misc** — [`tictactoe/`](examples/tictactoe), [`ai-chat/`](examples/ai-chat)
Examples using the [OpenAI Agents SDK](https://openai.github.io/openai-agents-js/) live in [`openai-sdk/`](openai-sdk). Work-in-progress experiments live in [`experimental/`](experimental) (no stability guarantees).
Run any example locally:
```sh
cd examples/playground
npm start
```
## Documentation
- [Full docs](https://developers.cloudflare.com/agents/) on developers.cloudflare.com
- [`docs/`](docs) directory in this repo (synced upstream)
- [Anthropic Patterns guide](guides/anthropic-patterns) — sequential, routing, parallel, orchestrator, evaluator
- [Human-in-the-Loop guide](guides/human-in-the-loop) — approval workflows with pause/resume
- [`design/`](design) — architecture and design decision records (chat API, sub-agents, agent tools, workspace, voice, browser tools, retries, and more)
## Repository Structure
| Directory | Description |
| ----------------------------------------------------- | -------------------------------------------------------- |
| [`packages/agents/`](packages/agents) | Core SDK |
| [`packages/ai-chat/`](packages/ai-chat) | AI chat layer |
| [`packages/think/`](packages/think) | Opinionated chat agent base |
| [`packages/codemode/`](packages/codemode) | Code Mode |
| [`packages/shell/`](packages/shell) | Deprecated sandboxed execution + filesystem |
| [`packages/voice/`](packages/voice) | Deprecated Voice compatibility wrapper |
| [`packages/worker-bundler/`](packages/worker-bundler) | Runtime Workers bundler |
| [`packages/hono-agents/`](packages/hono-agents) | Hono integration |
| [`examples/`](examples) | Self-contained demo apps |
| [`experimental/`](experimental) | Work-in-progress experiments (not published) |
| [`openai-sdk/`](openai-sdk) | Examples using the OpenAI Agents SDK |
| [`guides/`](guides) | In-depth pattern tutorials |
| [`docs/`](docs) | Markdown docs synced to developers.cloudflare.com |
| [`site/`](site) | Deployed websites (agents.cloudflare.com, AI playground) |
| [`design/`](design) | Architecture and design decision records |
| [`scripts/`](scripts) | Repo-wide tooling |
## Development
Node 24+ required. pnpm workspaces with [Nx](https://nx.dev) for task orchestration, caching, and affected detection.
```sh
pnpm install # install all workspaces
pnpm run build # build all packages (Nx, cached, dependency-ordered)
pnpm run check # sherif + export checks + oxfmt + oxlint + typecheck
pnpm run test # vitest + vitest-pool-workers (Workers runtime)
pnpm run test:react # Playwright-based React hook tests
pnpm exec nx affected -t build # build only what changed
pnpm exec nx affected -t test # test only what changed
```
Changes to `packages/` need a changeset:
```sh
pnpm exec changeset
```
See [`AGENTS.md`](AGENTS.md) for deeper contributor guidance.
## Contributing
We are not accepting external pull requests at this time — the SDK is evolving quickly and we want to keep the surface area manageable. That said, we'd love to hear from you:
- **Bug reports & feature requests** — [open an issue](https://github.com/cloudflare/agents/issues)
- **Questions & ideas** — [start a discussion](https://github.com/cloudflare/agents/discussions)
## License
[MIT](LICENSE)