ElevenLabs stream() playback requires the mpv executable installed on your system; the SDK does not bundle it. Install mpv from mpv.io, and if you use a virtualenv, append mpv's install directory to os.environ PATH before calling play. For headless servers, skip play() and write the streamed bytes to a file instead.

Context: ElevenLabs python SDK issue #49 (closed): streaming audio playback failed with ValueError: mpv not found. The SDK's play() helper shells out to the mpv media player, which is not bundled with the SDK. Maintainers flavioschneider and yunusdemir explained you must install mpv separately (mpv.io installation builds or unofficial executables), and if you run in a virtual environment you may need to add mpv's directory to PATH manually.