sandbox-agent/docs/sdk-overview.mdx

---
title: "SDK Overview"
description: "Use the TypeScript SDK to manage Sandbox Agent sessions and APIs."
icon: "compass"
---

The TypeScript SDK is centered on `sandbox-agent` and its `SandboxAgent` class.

## Install

<Tabs>
  <Tab title="npm">
    ```bash
    npm install sandbox-agent@0.2.x
    ```
  </Tab>
  <Tab title="bun">
    ```bash
    bun add sandbox-agent@0.2.x
    # Allow Bun to run postinstall scripts for native binaries (required for SandboxAgent.start()).
    bun pm trust @sandbox-agent/cli-linux-x64 @sandbox-agent/cli-linux-arm64 @sandbox-agent/cli-darwin-arm64 @sandbox-agent/cli-darwin-x64 @sandbox-agent/cli-win32-x64
    ```
  </Tab>
</Tabs>

## Optional persistence drivers

```bash
npm install @sandbox-agent/persist-indexeddb@0.2.x @sandbox-agent/persist-sqlite@0.2.x @sandbox-agent/persist-postgres@0.2.x
```

## Create a client

```ts
import { SandboxAgent } from "sandbox-agent";

const sdk = await SandboxAgent.connect({
  baseUrl: "http://127.0.0.1:2468",
});
```

With a custom fetch handler (for example, proxying requests inside Workers):

```ts
const sdk = await SandboxAgent.connect({
  fetch: (input, init) => customFetch(input, init),
});
```

With persistence:

```ts
import { SandboxAgent } from "sandbox-agent";
import { SQLiteSessionPersistDriver } from "@sandbox-agent/persist-sqlite";

const persist = new SQLiteSessionPersistDriver({
  filename: "./sessions.db",
});

const sdk = await SandboxAgent.connect({
  baseUrl: "http://127.0.0.1:2468",
  persist,
});
```

Local autospawn (Node.js only):

```ts
import { SandboxAgent } from "sandbox-agent";

const localSdk = await SandboxAgent.start();

await localSdk.dispose();
```

## Session flow

```ts
const session = await sdk.createSession({
  agent: "mock",
  sessionInit: {
    cwd: "/",
    mcpServers: [],
  },
});

const prompt = await session.prompt([
  { type: "text", text: "Summarize this repository." },
]);

console.log(prompt.stopReason);
```

Load and destroy:

```ts
const restored = await sdk.resumeSession(session.id);
await restored.prompt([{ type: "text", text: "Continue from previous context." }]);

await sdk.destroySession(restored.id);
```

## Session configuration

Set model, mode, or thought level at creation or on an existing session:

```ts
const session = await sdk.createSession({
  agent: "codex",
  model: "gpt-5.3-codex",
});

await session.setModel("gpt-5.2-codex");
await session.setMode("auto");

const options = await session.getConfigOptions();
const modes = await session.getModes();
```

See [Agent Sessions](/agent-sessions) for full details on config options and error handling.

## Events

Subscribe to live events:

```ts
const unsubscribe = session.onEvent((event) => {
  console.log(event.eventIndex, event.sender, event.payload);
});

await session.prompt([{ type: "text", text: "Give me a short summary." }]);
unsubscribe();
```

Fetch persisted events:

```ts
const page = await sdk.getEvents({
  sessionId: session.id,
  limit: 100,
});

console.log(page.items.length);
```

## Control-plane and HTTP helpers

```ts
const health = await sdk.getHealth();
const agents = await sdk.listAgents();
await sdk.installAgent("codex", { reinstall: true });

const entries = await sdk.listFsEntries({ path: "." });
const writeResult = await sdk.writeFsFile({ path: "./hello.txt" }, "hello");

console.log(health.status, agents.agents.length, entries.length, writeResult.path);
```

## Error handling

```ts
import { SandboxAgentError } from "sandbox-agent";

try {
  await sdk.listAgents();
} catch (error) {
  if (error instanceof SandboxAgentError) {
    console.error(error.status, error.problem);
  }
}
```

## Inspector URL

```ts
import { buildInspectorUrl } from "sandbox-agent";

const url = buildInspectorUrl({
  baseUrl: "https://your-sandbox-agent.example.com",
  headers: { "X-Custom-Header": "value" },
});

console.log(url);
```

Parameters:

- `baseUrl` (required unless `fetch` is provided): Sandbox Agent server URL
- `token` (optional): Bearer token for authenticated servers
- `headers` (optional): Additional request headers
- `fetch` (optional): Custom fetch implementation used by SDK HTTP and ACP calls