generate-speech

name	generate-speech
description	Generate multilingual WAV voice-overs and voice auditions from text with Gemini TTS. Use when the user asks to synthesize speech, narrate a demo video, compare Gemini voices, or create spoken audio in one or more languages.

Generate Speech

Use Gemini TTS to create multilingual voice-overs. Preserve the supplied script exactly unless the user asks for rewriting.

Generate audio

1. Require GEMINI_API_KEY in the environment. Never print or store it.

2. Choose a voice from references/voices.md. Default to Kore only when the user has no preference and does not want auditions.

3. Use a .wav output path that does not already exist.

4. Run the bundled script:

   uv run scripts/generate_speech.py \
     --output /absolute/path/voice-over.wav \
     --voice Kore \
     --text 'Testo da leggere'
   

   Use --file for longer scripts and --instructions for delivery guidance:

   uv run scripts/generate_speech.py \
     --output /absolute/path/voice-over.wav \
     --voice Sulafat \
     --instructions 'Speak warmly, at a measured pace, in a natural Italian accent.' \
     --file /absolute/path/script.txt
   

5. Verify that the output exists and is a non-empty WAV file, then return its absolute path.

Audition voices

Select a small set based on the documented characteristics and generate the same short passage with each voice. Name samples predictably, such as it-sulafat.wav and it-achird.wav. Do not generate all voices unless explicitly requested; each sample is a separate API request.

Constraints

• Require exactly one of --text or --file.
• Use gemini-3.1-flash-tts-preview unless the user explicitly requests another TTS model.
• Treat style, tone, accent, and pace as prompt instructions, not modifications to the script.
• Remember that Gemini TTS is a preview service: long output can drift, so split scripts longer than a few minutes.
• Do not overwrite existing audio files.