> ## Documentation Index
> Fetch the complete documentation index at: https://sunpeak.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP Apps getHostVersion - Host Identification

> Read the host application's name and version from an MCP App. Use getHostVersion to identify whether the app is running in ChatGPT, Claude, or another host.

<Badge color="green">MCP Apps SDK</Badge>

```ts theme={null}
import { App } from "@modelcontextprotocol/ext-apps";
```

## Overview

`getHostVersion()` returns the host application's name and version, as reported during the [initialization handshake](/mcp-apps/lifecycle#2-initialization). Use this to identify the host platform, log diagnostics, or adapt behavior for specific hosts.

Returns `undefined` before `connect()` completes.

## Signature

```ts theme={null}
getHostVersion(): { name: string; version: string } | undefined
```

## Returns

<ResponseField name="return" type="{ name: string; version: string } | undefined">
  The host's self-reported identity, or `undefined` if the app has not connected yet.

  <ResponseField name="name" type="string">
    The host application name (e.g., `"ChatGPT"`, `"Claude"`).
  </ResponseField>

  <ResponseField name="version" type="string">
    The host application version string.
  </ResponseField>
</ResponseField>

## Usage

### Log the host identity

```ts theme={null}
await app.connect();

const host = app.getHostVersion();
console.log(`Running in ${host?.name} v${host?.version}`);
// → "Running in ChatGPT v1.0.0"
```

### Adapt behavior per host

```ts theme={null}
const host = app.getHostVersion();

if (host?.name === "ChatGPT") {
  // ChatGPT-specific initialization
} else if (host?.name === "Claude") {
  // Claude-specific initialization
}
```

### Include in error reports

```ts theme={null}
function reportError(error: Error) {
  const host = app.getHostVersion();
  sendToErrorService({
    error: error.message,
    hostName: host?.name,
    hostVersion: host?.version,
    appVersion: "1.0.0",
  });
}
```

## Related

* [`getHostCapabilities()`](/mcp-apps/app/accessors/get-host-capabilities) — What the host supports
* [`getHostContext()`](/mcp-apps/app/accessors/get-host-context) — Theme, locale, and display state
* [Accessors overview](/mcp-apps/app/accessors) — All App accessor methods

<Tip>
  The [sunpeak framework](/quickstart) provides [`useHostInfo`](/app-framework/hooks/use-host-info) for reactive access to the host's name and version in React components.
</Tip>