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# Function hostDevBuild

*   <a id="hostdevbuild"></a>
    
    ```typescript
    hostDevBuild(): boolean | null
    ```
    
    Module-level read of the host build flavor — `true` for an unpackaged dev host, `false` for a packaged one, `null` before the first theme frame carried the flag (or under an older host). Convenience for apps that call `connectToHost()` fire-and-forget without keeping the handle; listen for the `ispo:theme` DOM event to re-read once the bootstrap frame lands.
    
    #### Returns boolean | null