> ## 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.

# usePlatform

> Get the host-reported platform type.

<Badge color="yellow">sunpeak API</Badge>

## Overview

The `usePlatform` hook returns the platform type reported by the host. It is a convenience wrapper around `useHostContext`.

<Tip>This returns the host-reported platform from [`McpUiHostContext.platform`](/mcp-apps/types/core-types#mcpuihostcontext), not a runtime detection. For runtime host detection (ChatGPT vs Claude), see [`detectHost`](/app-framework/functions/host-detection).</Tip>

<Card horizontal title="Wraps onhostcontextchanged" icon="cube" href="/mcp-apps/app/event-handlers/onhostcontextchanged">
  MCP Apps SDK reference
</Card>

## Import

```tsx theme={null}
import { usePlatform } from 'sunpeak';
```

## Signature

```tsx theme={null}
function usePlatform(): HostPlatform | undefined
```

## Returns

<ResponseField name="return" type="'web' | 'desktop' | 'mobile' | undefined">
  The platform type reported by the host. `undefined` if the host does not report a platform.
</ResponseField>

## Usage

```tsx theme={null}
import { usePlatform } from 'sunpeak';

function MyResource() {
  const platform = usePlatform();

  return (
    <div className={platform === 'mobile' ? 'p-2 text-sm' : 'p-4'}>
      Running on {platform ?? 'unknown platform'}
    </div>
  );
}
```

The platform value comes from [`McpUiHostContext.platform`](/mcp-apps/types/core-types#mcpuihostcontext).