---
title: Getting started
description: Build a Think chat agent with persistent memory, built-in file tools, custom tools, and streaming, step by step.
image: https://edgetunnel-b2h.pages.dev/dev-products-preview.png
---

> Documentation Index  
> Fetch the complete documentation index at: https://edgetunnel-b2h.pages.dev/agents/llms.txt  
> Use this file to discover all available pages before exploring further. 

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# Getting started

Build a chat agent with persistent memory, built-in file tools, and streaming — step by step.

If you are brand new to Cloudflare Agents, skim [What are agents?](https://edgetunnel-b2h.pages.dev/agents/concepts/what-are-agents/) first for the core ideas. Otherwise, you can follow along here from scratch.

By the end of this tutorial you will have a Think agent that:

* Streams responses to a React chat UI
* Has persistent memory the model can read and write
* Includes workspace file tools (read, write, edit, find, grep, delete)
* Supports custom server-side tools

## Prerequisites

* Node.js 24+
* A Cloudflare account with Workers AI access
* Familiarity with TypeScript and Cloudflare Workers

## 1\. Create a project

```sh
mkdir my-think-agent && cd my-think-agent
npm init -y
```

Install dependencies:

```sh
npm install @cloudflare/think @cloudflare/ai-chat agents ai @cloudflare/shell zod workers-ai-provider react react-dom
npm install -D wrangler @cloudflare/vite-plugin @cloudflare/workers-types @vitejs/plugin-react @tailwindcss/vite tailwindcss typescript vite
```

## 2\. Configure wrangler

Create `wrangler.jsonc`:

* [  wrangler.jsonc ](#tab-panel-6095)
* [  wrangler.toml ](#tab-panel-6096)

**JSONC**

```jsonc
{
  "name": "my-think-agent",
  "compatibility_date": "2026-01-28",
  "compatibility_flags": ["nodejs_compat"],
  "ai": { "binding": "AI" },
  "assets": {
    "not_found_handling": "single-page-application",
    "run_worker_first": ["/agents/*"]
  },
  "durable_objects": {
    "bindings": [{ "class_name": "MyAgent", "name": "MyAgent" }]
  },
  "migrations": [{ "new_sqlite_classes": ["MyAgent"], "tag": "v1" }],
  "main": "src/server.ts"
}
```

**TOML**

```toml
name = "my-think-agent"
compatibility_date = "2026-01-28"
compatibility_flags = [ "nodejs_compat" ]
main = "src/server.ts"


[ai]
binding = "AI"


[assets]
not_found_handling = "single-page-application"
run_worker_first = [ "/agents/*" ]


[[durable_objects.bindings]]
class_name = "MyAgent"
name = "MyAgent"


[[migrations]]
new_sqlite_classes = [ "MyAgent" ]
tag = "v1"
```

Create `vite.config.ts`:

* [  JavaScript ](#tab-panel-6097)
* [  TypeScript ](#tab-panel-6098)

**JavaScript**

```js
import { cloudflare } from "@cloudflare/vite-plugin";
import tailwindcss from "@tailwindcss/vite";
import react from "@vitejs/plugin-react";
import { defineConfig } from "vite";


export default defineConfig({
  plugins: [react(), cloudflare(), tailwindcss()],
});
```

**TypeScript**

```ts
import { cloudflare } from "@cloudflare/vite-plugin";
import tailwindcss from "@tailwindcss/vite";
import react from "@vitejs/plugin-react";
import { defineConfig } from "vite";


export default defineConfig({
  plugins: [react(), cloudflare(), tailwindcss()],
});
```

Create `tsconfig.json`:

```json
{
  "extends": "agents/tsconfig"
}
```

## 3\. Define the agent

Create `src/server.ts`:

* [  JavaScript ](#tab-panel-6099)
* [  TypeScript ](#tab-panel-6100)

**JavaScript**

```js
import { Think } from "@cloudflare/think";
import { createWorkersAI } from "workers-ai-provider";
import { routeAgentRequest } from "agents";


export class MyAgent extends Think {
  getModel() {
    return createWorkersAI({ binding: this.env.AI })(
      "@cf/moonshotai/kimi-k2.6",
    );
  }


  getSystemPrompt() {
    return "You are a helpful assistant with access to a workspace filesystem.";
  }
}


export default {
  async fetch(request, env) {
    return (
      (await routeAgentRequest(request, env)) ||
      new Response("Not found", { status: 404 })
    );
  },
};
```

**TypeScript**

```ts
import { Think } from "@cloudflare/think";
import { createWorkersAI } from "workers-ai-provider";
import { routeAgentRequest } from "agents";


export class MyAgent extends Think<Env> {
  getModel() {
    return createWorkersAI({ binding: this.env.AI })(
      "@cf/moonshotai/kimi-k2.6",
    );
  }


  getSystemPrompt() {
    return "You are a helpful assistant with access to a workspace filesystem.";
  }
}


export default {
  async fetch(request: Request, env: Env) {
    return (
      (await routeAgentRequest(request, env)) ||
      new Response("Not found", { status: 404 })
    );
  },
} satisfies ExportedHandler<Env>;
```

This is a working agent. Think automatically provides:

* WebSocket chat protocol (compatible with `useAgentChat`)
* Message persistence in SQLite
* Resumable streaming (page refresh replays buffered chunks)
* Workspace file tools (read, write, edit, list, find, grep, delete)
* Abort/cancel support
* Error handling with partial message persistence

## 4\. Connect a React client

Create `src/client.tsx`:

* [  JavaScript ](#tab-panel-6107)
* [  TypeScript ](#tab-panel-6108)

**JavaScript**

```js
import { createRoot } from "react-dom/client";
import { useAgent } from "agents/react";
import { useAgentChat } from "@cloudflare/ai-chat/react";


function Chat() {
  const agent = useAgent({ agent: "MyAgent" });
  const { messages, sendMessage, status } = useAgentChat({ agent });


  return (
    <div>
      <h1>Think Agent</h1>
      {messages.map((msg) => (
        <div key={msg.id}>
          <strong>{msg.role}:</strong>
          {msg.parts.map((part, i) =>
            part.type === "text" ? <span key={i}>{part.text}</span> : null,
          )}
        </div>
      ))}


      <form
        onSubmit={(e) => {
          e.preventDefault();
          const input = e.currentTarget.elements.namedItem("input");
          if (!input.value.trim()) return;
          sendMessage({ text: input.value });
          input.value = "";
        }}
      >
        <input name="input" placeholder="Send a message..." />
        <button type="submit">Send</button>
      </form>


      <p>Status: {status}</p>
    </div>
  );
}


const root = document.getElementById("root");
if (root) {
  createRoot(root).render(<Chat />);
}
```

**TypeScript**

```ts
import { createRoot } from "react-dom/client";
import { useAgent } from "agents/react";
import { useAgentChat } from "@cloudflare/ai-chat/react";


function Chat() {
  const agent = useAgent({ agent: "MyAgent" });
  const { messages, sendMessage, status } = useAgentChat({ agent });


  return (
    <div>
      <h1>Think Agent</h1>
      {messages.map((msg) => (
        <div key={msg.id}>
          <strong>{msg.role}:</strong>
          {msg.parts.map((part, i) =>
            part.type === "text" ? <span key={i}>{part.text}</span> : null,
          )}
        </div>
      ))}


      <form
        onSubmit={(e) => {
          e.preventDefault();
          const input = e.currentTarget.elements.namedItem(
            "input",
          ) as HTMLInputElement;
          if (!input.value.trim()) return;
          sendMessage({ text: input.value });
          input.value = "";
        }}
      >
        <input name="input" placeholder="Send a message..." />
        <button type="submit">Send</button>
      </form>


      <p>Status: {status}</p>
    </div>
  );
}


const root = document.getElementById("root");
if (root) {
  createRoot(root).render(<Chat />);
}
```

Create `index.html`:

```html
<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Think Agent</title>
  </head>
  <body>
    <div id="root"></div>
    <script type="module" src="/src/client.tsx"></script>
  </body>
</html>
```

## 5\. Run it

```sh
npx vite dev
```

Open the browser and send a message. The agent responds with streaming text, and workspace file tools are available to the model automatically.

## 6\. Add persistent memory

Override `configureSession` to give the model writable memory that survives restarts:

* [  JavaScript ](#tab-panel-6101)
* [  TypeScript ](#tab-panel-6102)

**JavaScript**

```js
export class MyAgent extends Think {
  getModel() {
    return createWorkersAI({ binding: this.env.AI })(
      "@cf/moonshotai/kimi-k2.6",
    );
  }


  configureSession(session) {
    return session
      .withContext("soul", {
        provider: {
          get: async () =>
            "You are a helpful assistant. Remember important facts about the user.",
        },
      })
      .withContext("memory", {
        description: "Important facts about the user and conversation.",
        maxTokens: 2000,
      })
      .withCachedPrompt();
  }
}
```

**TypeScript**

```ts
export class MyAgent extends Think<Env> {
  getModel(): LanguageModel {
    return createWorkersAI({ binding: this.env.AI })(
      "@cf/moonshotai/kimi-k2.6",
    );
  }


  configureSession(session: Session) {
    return session
      .withContext("soul", {
        provider: {
          get: async () =>
            "You are a helpful assistant. Remember important facts about the user.",
        },
      })
      .withContext("memory", {
        description: "Important facts about the user and conversation.",
        maxTokens: 2000,
      })
      .withCachedPrompt();
  }
}
```

Now the model sees a `MEMORY` section in its system prompt and gets a `set_context` tool to update it. Facts written to memory persist in SQLite and survive Durable Object hibernation and restarts.

When you use `configureSession`, the system prompt is built from context blocks rather than `getSystemPrompt()`. The `"soul"` block above acts as the system identity — it is read-only and always appears first. The `"memory"` block is writable, and the model proactively updates it when it learns something useful.

Refer to the [Sessions documentation](https://edgetunnel-b2h.pages.dev/agents/runtime/lifecycle/sessions/) for context blocks, compaction, search, skills, and multi-session support.

## 7\. Add custom tools

Override `getTools()` to add your own tools alongside the built-in workspace tools:

* [  JavaScript ](#tab-panel-6105)
* [  TypeScript ](#tab-panel-6106)

**JavaScript**

```js
import { tool } from "ai";
import { z } from "zod";


export class MyAgent extends Think {
  getModel() {
    /* ... */
  }
  configureSession(session) {
    /* ... */
  }


  getTools() {
    return {
      getWeather: tool({
        description: "Get the current weather for a city",
        inputSchema: z.object({
          city: z.string().describe("City name"),
        }),
        execute: async ({ city }) => {
          const res = await fetch(
            `https://api.weatherapi.com/v1/current.json?key=${this.env.WEATHER_KEY}&q=${city}`,
          );
          return res.json();
        },
      }),
    };
  }
}
```

**TypeScript**

```ts
import { tool } from "ai";
import { z } from "zod";


export class MyAgent extends Think<Env> {
  getModel(): LanguageModel {
    /* ... */
  }
  configureSession(session: Session) {
    /* ... */
  }


  getTools(): ToolSet {
    return {
      getWeather: tool({
        description: "Get the current weather for a city",
        inputSchema: z.object({
          city: z.string().describe("City name"),
        }),
        execute: async ({ city }) => {
          const res = await fetch(
            `https://api.weatherapi.com/v1/current.json?key=${this.env.WEATHER_KEY}&q=${city}`,
          );
          return res.json();
        },
      }),
    };
  }
}
```

Think merges tools from multiple sources automatically. On every turn, the model has access to:

1. **Workspace tools** — read, write, edit, list, find, grep, delete, bash (built-in)
2. **Your tools** — from `getTools()`
3. **Extension tools** — from loaded extensions
4. **Session tools** — set\_context, load\_context, search\_context (from `configureSession`)
5. **Skill tools** — activate\_skill, read\_skill\_resource, and optional run\_skill\_script (from `getSkills()`)
6. **MCP tools** — from connected MCP servers (if any)
7. **Client tools** — from the browser (if any)

## 8\. Add lifecycle hooks

Think provides hooks that fire on every turn, regardless of entry path:

* [  JavaScript ](#tab-panel-6103)
* [  TypeScript ](#tab-panel-6104)

**JavaScript**

```js
export class MyAgent extends Think {
  getModel() {
    /* ... */
  }


  beforeTurn(ctx) {
    console.log(
      `Turn starting: ${Object.keys(ctx.tools).length} tools available`,
    );
  }


  onChatResponse(result) {
    console.log(`Turn ${result.status}: ${result.message.parts.length} parts`);
  }
}
```

**TypeScript**

```ts
import type {
  TurnContext,
  TurnConfig,
  ChatResponseResult,
} from "@cloudflare/think";


export class MyAgent extends Think<Env> {
  getModel(): LanguageModel {
    /* ... */
  }


  beforeTurn(ctx: TurnContext): TurnConfig | void {
    console.log(
      `Turn starting: ${Object.keys(ctx.tools).length} tools available`,
    );
  }


  onChatResponse(result: ChatResponseResult) {
    console.log(`Turn ${result.status}: ${result.message.parts.length} parts`);
  }
}
```

Refer to [Lifecycle hooks](https://edgetunnel-b2h.pages.dev/agents/harnesses/think/lifecycle-hooks/) for the full reference.

## Next steps

* [Lifecycle hooks](https://edgetunnel-b2h.pages.dev/agents/harnesses/think/lifecycle-hooks/) — control model behavior, switch models per-turn, restrict tools
* [Tools](https://edgetunnel-b2h.pages.dev/agents/harnesses/think/tools/) — workspace tools, code execution, extensions
* [Client tools](https://edgetunnel-b2h.pages.dev/agents/harnesses/think/client-tools/) — browser-side tools, approval flows, concurrency
* [Sub-agent RPC and programmatic turns](https://edgetunnel-b2h.pages.dev/agents/harnesses/think/sub-agents/) — RPC streaming, scheduled turns, recovery
* [Sessions](https://edgetunnel-b2h.pages.dev/agents/runtime/lifecycle/sessions/) — context blocks, compaction, search, multi-session

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