Synthesise Speech#

Generate spoken audio with yummycli gemini speak using Google Gemini TTS.

When to Use#

Load this skill when the user asks to synthesise speech, convert text to audio, generate a voiceover, create a narration, or produce a spoken dialogue — including single-speaker TTS and multi-speaker conversation.

Prerequisite: Apply the yummy-shared skill first.

This skill covers three modes with a single command:

• Single-speaker narration (one voice, any language)
• Multi-speaker dialogue (up to 2 speakers, each with their own voice)
• Listing available prebuilt voices

Command Contract#

Two equivalent entry points are available:

Entry pointWhen to useyummycli gemini speakDefault — human-friendly, Gemini TTS presets appliedyummycli audio speak --provider geminiScripting / automation — explicit, provider-agnostic form

Both share the same flags and defaults. Prefer gemini speak unless the task explicitly requires the provider-agnostic form.

Basic usage:

bash

yummycli gemini speak --text "<text>"

With an explicit voice and output path:

bash

yummycli gemini speak \
  --text "<text>" \
  --voice Kore \
  --output narration.wav

Optional controls:

bash

--output <file.wav>
--model <model>
--voice <voice-name>
--language <bcp47-code>

Default values when omitted: --model gemini-3.1-flash-tts-preview, --voice Aoede.

Speaker Routing Rules#

The presence of --speaker flags determines the synthesis path automatically:

InputBehaviourNo --speakerSingle-speaker synthesis. --voice selects the prebuilt voice.1–2 --speaker flagsMulti-speaker dialogue. Each flag maps a speaker name to a voice. --voice must not be used together.

--voice and --speaker are mutually exclusive. Never pass both.

Model Selection#

Default model: gemini-3.1-flash-tts-preview.

User saysUse3.1, 3.1 flash, or no preferencegemini-3.1-flash-tts-preview (default)2.5 flash or flash 2.5``gemini-2.5-flash-preview-tts``2.5 pro or pro 2.5``gemini-2.5-pro-preview-tts

Do not switch models from vague quality words alone.

Available Voices#

30 prebuilt voices are available. Run yummycli gemini voices to list them all.

VoiceStyleAoedeBreezyKoreFirmCharonInformativePuckUpbeatFenrirExcitableZephyrBrightLedaYouthfulOrusFirmCallirrhoeEasy-goingAutonoeBrightEnceladusBreathyIapetusClearUmbrielEasy-goingAlgiebaSmoothDespinaSmoothErinomeClearAlgenibGravellyRasalghulInformativeAchirdFriendlyZubenelgenubiCasualVindemiatrixGentleSadachbiaLivelySadaltagerKnowledgeableSulafatWarmSchedarEvenGacruxMaturePulcherrimaForwardLaomedeiaUpbeatAchernarSoftAlnilamFirm

When the user does not specify a voice, use the default ( Aoede). Only apply a different voice when the user explicitly names one or describes a style that clearly maps to a specific voice.

Language#

• Language is auto-detected from the input text when --language is omitted.
• Pass --language only when the user explicitly specifies a language or when the text could be ambiguous (e.g. romanised transliteration).
• Use BCP-47 codes: en-US, zh-CN, ja-JP, ko-KR, fr-FR, etc.

Intent to Parameters#

Voice guidance:

• For neutral or general-purpose narration, use the default Aoede (Breezy).
• For formal or instructional content, consider Charon (Informative) or Kore (Firm).
• For energetic or promotional content, consider Puck (Upbeat) or Fenrir (Excitable).
• For warm conversational content, consider Sulafat (Warm) or Achird (Friendly).
• Only switch from the default when the user's intent clearly maps to a specific style.

Output path guidance:

• If --output is omitted, yummycli generates a timestamped .wav filename in the current working directory. Do not invent your own filename unless the user provides one.
• The output path must end in .wav. Reject or correct any other extension.

Multi-speaker prompt format:

• Each speaker's lines must be tagged with their name in square brackets: [Alice]: Hello! [Bob]: Hi there!
• Speaker names in --speaker flags must exactly match the names used in --text.

Output Contract#

Speak commands return JSON on stdout. Read the response and use the output field as the generated file path.

Single-speaker example:

json

{
  "provider": "gemini",
  "output": "tts_20260420_142301_047.wav",
  "model": "gemini-3.1-flash-tts-preview",
  "voice": "Aoede",
  "elapsed_seconds": 3
}

Multi-speaker example:

json

{
  "provider": "gemini",
  "output": "dialogue_20260420_143010_112.wav",
  "model": "gemini-3.1-flash-tts-preview",
  "speakers": [
    {"name": "Alice", "voice": "Aoede"},
    {"name": "Bob", "voice": "Kore"}
  ],
  "elapsed_seconds": 4
}

Execution Rules#

• Check yummycli auth status --provider gemini before running if credentials may not be configured.
• Never pass --voice and --speaker together.
• Never pass more than 2 --speaker flags — the API rejects it.
• Speaker names in --speaker flags must match the names used in the --text prompt exactly.
• If the command returns a validation error, fix the arguments before retrying. Do not retry with the same invalid arguments.
• Report the final output path back to the user after a successful run.

Examples#

Single-speaker narration:

bash

yummycli gemini speak \
  --text "A golden retriever is the best dog in the world."

Narration with an explicit voice:

bash

yummycli gemini speak \
  --text "Welcome to the future of AI-powered audio." \
  --voice Puck \
  --output welcome.wav

Chinese narration (auto-detected language):

bash

yummycli gemini speak \
  --text "你好，欢迎使用 Gemini 语音合成服务。" \
  --voice Aoede \
  --output greeting.wav

Multi-speaker dialogue:

bash

yummycli gemini speak \
  --text "[Alice]: 你好！今天天气真好。 [Bob]: 是啊，我们去散步吧！" \
  --speaker Alice:Aoede \
  --speaker Bob:Kore \
  --output dialogue.wav

List all available voices:

bash

yummycli gemini voices