Tts

Text-to-Speech (voice notes)

Generate a spoken voice note from text and deliver it as a native Telegram voice message. You produce the audio file with the script below, then send it with the send_file MCP tool — the host routes .ogg to sendVoice automatically, so it shows up as a real voice bubble (with waveform + play).

When to speak vs. write

• Speak when the user explicitly asks (say / speak / read aloud / voice message), or when a spoken reply is clearly the better experience.
• Write for everything else. Voice is a deliberate choice, not the default. Don't narrate long technical answers as audio unless asked.

How to generate + send

The credential is handled by the OneCLI gateway — you never set an API key.

# Short text inline:
bun /app/skills/tts/scripts/tts.ts --text "Hey! On my way, fifteen minutes." --out voice.ogg

# Longer text via stdin (avoids quoting issues):
echo "Once upon a time, in a quiet harbor town…" | bun /app/skills/tts/scripts/tts.ts --out story.ogg

The script prints the absolute path of the finished .ogg on success. Pass that exact path to send_file:

send_file({ to: "<destination>", path: "<printed absolute path>", text: "(optional caption)" })

Use the printed path rather than a bare filename so it resolves no matter the working directory. Send it with no text for a pure voice note, or add a short caption.

Options

• --voice <name> — default Alnilam (firm, masculine). Other voices include Puck, Charon, Aoede, Leda, Fenrir, Zephyr (30 total). Pick one that fits the persona and keep it consistent.
• --model <id> — default gemini-3.1-flash-tts-preview (latest, most expressive). Don't change unless you have a reason.
• --out <file> — output filename (default voice.ogg). Must end in .ogg for a Telegram voice bubble; other audio extensions are sent as music files.

Languages (Ukrainian, English, 70+ more)

The model auto-detects the language from your text — just write in the target language. Ukrainian (uk) and English (en) are both fully supported, and you can mix them. Two rules from Google's docs:

• Audio tags stay in English even when the speech isn't. Write Ukrainian text with English tags. Example: --text "[привітно] Привіт! [laughs] Я щойно навчився говорити." (the [laughs] tag is English, the spoken words are Ukrainian).
• Accents come from a style instruction, not the language. To shape an accent, describe it (see below) rather than relying on the language code.

Audio tags (expressive control)

Tags are inline [square-bracket] cues that steer delivery. The model reads the meaning of your text, so tags fine-tune emotion, pace, and non-verbal sounds. Google's formula:

[pacing tag] spoken text [expressive tag] spoken text [pause tag] spoken text

Rules (important — follow exactly):

• Tags are English only; the spoken text can be any language.
• Put a tag exactly where the change should happen.
• Always separate tags with text or punctuation — never place two tags back-to-back ([slow][whispers] errors; [slow] well… [whispers] is fine).

Common tags:

• Emotion: [excited], [happy], [serious], [sad], [nervous], [curious], [sarcastic], [angry], [hopeful], [amused]
• Non-verbal: [laughs], [sighs], [gasp], [whispers], [shouting], [giggles], [cough]
• Pacing: [slow], [fast], [short pause], [long pause]

The list isn't exhaustive — descriptive tags work too ([reluctantly], [like telling a secret]). Example: --text "[excited] We did it! [laughs] [short pause] I honestly can't believe it worked."

Voice matching

Pick a --voice whose character reinforces the mood, and keep it consistent for a persona. A few of the 30: Alnilam (firm — the default), Puck (upbeat), Aoede (breezy), Enceladus (breathy — good for tired/intimate), Achird (friendly), Sulafat (warm), Charon (informative). The voice and the text's tone should agree — don't push a deep firm voice to sound like a giddy child.

Optional: richer direction

For a more crafted performance you can prepend a short natural-language style note, e.g. --text "Say warmly and slowly: бережи себе сьогодні." or describe style/pacing/accent in a sentence before the line.

Safety rule when you do this: the model can occasionally read your directions aloud if it can't tell instruction from script. So when you add a style preamble, make the spoken part unambiguous — phrase it as Read this aloud: "<the exact words>". For a plain voice note with inline tags only (the common case), no preamble is needed.

Notes

• This is a metered Google API (separate from the Claude subscription) — roughly $0.018 per minute of audio. Cheap, but don't generate long speech casually; prefer short voice notes.
• Output is OGG/Opus, 24 kHz mono — correct for Telegram voice. All audio is SynthID-watermarked by Google.
• If the call fails with a 401/403, the Gemini key isn't connected — tell the user to add it in OneCLI; do not ask them for a raw key.