Text-to-speech

​

Quick start

{
  tts: {
    auto: "always",
    provider: "elevenlabs",
  },
}

​

Supported providers

​

Configuration

{
  tts: {
    auto: "always",
    provider: "azure-speech",
    providers: {
      "azure-speech": {
        apiKey: "${AZURE_SPEECH_KEY}",
        region: "eastus",
        speakerVoice: "en-US-JennyNeural",
        lang: "en-US",
        outputFormat: "audio-24khz-48kbitrate-mono-mp3",
        voiceNoteOutputFormat: "ogg-24khz-16bit-mono-opus",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "elevenlabs",
    providers: {
      elevenlabs: {
        apiKey: "${ELEVENLABS_API_KEY}",
        model: "eleven_multilingual_v2",
        speakerVoiceId: "EXAVITQu4vr4xnSDxMaL",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "google",
    providers: {
      google: {
        apiKey: "${GEMINI_API_KEY}",
        model: "gemini-3.1-flash-tts-preview",
        speakerVoice: "Kore",
        // Optional natural-language style prompts:
        // audioProfile: "Speak in a calm, podcast-host tone.",
        // speakerName: "Alex",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "gradium",
    providers: {
      gradium: {
        apiKey: "${GRADIUM_API_KEY}",
        speakerVoiceId: "YTpq7expH9539ERJ",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "inworld",
    providers: {
      inworld: {
        apiKey: "${INWORLD_API_KEY}",
        modelId: "inworld-tts-1.5-max",
        speakerVoiceId: "Sarah",
        temperature: 0.7,
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "tts-local-cli",
    providers: {
      "tts-local-cli": {
        command: "say",
        args: ["-o", "{{OutputPath}}", "{{Text}}"],
        outputFormat: "wav",
        timeoutMs: 120000,
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "microsoft",
    providers: {
      microsoft: {
        enabled: true,
        speakerVoice: "en-US-MichelleNeural",
        lang: "en-US",
        outputFormat: "audio-24khz-48kbitrate-mono-mp3",
        rate: "+0%",
        pitch: "+0%",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "minimax",
    providers: {
      minimax: {
        apiKey: "${MINIMAX_API_KEY}",
        model: "speech-2.8-hd",
        speakerVoiceId: "English_expressive_narrator",
        speed: 1.0,
        vol: 1.0,
        pitch: 0,
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "openai",
    summaryModel: "openai/gpt-4.1-mini",
    modelOverrides: { enabled: true },
    providers: {
      openai: {
        apiKey: "${OPENAI_API_KEY}",
        model: "gpt-4o-mini-tts",
        speakerVoice: "alloy",
      },
      elevenlabs: {
        apiKey: "${ELEVENLABS_API_KEY}",
        model: "eleven_multilingual_v2",
        speakerVoiceId: "EXAVITQu4vr4xnSDxMaL",
        voiceSettings: { stability: 0.5, similarityBoost: 0.75, style: 0.0, useSpeakerBoost: true, speed: 1.0 },
        applyTextNormalization: "auto",
        languageCode: "en",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "openrouter",
    providers: {
      openrouter: {
        apiKey: "${OPENROUTER_API_KEY}",
        model: "hexgrad/kokoro-82m",
        speakerVoice: "af_alloy",
        responseFormat: "mp3",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "volcengine",
    providers: {
      volcengine: {
        apiKey: "${VOLCENGINE_TTS_API_KEY}",
        resourceId: "seed-tts-1.0",
        speakerVoice: "en_female_anna_mars_bigtts",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "xai",
    providers: {
      xai: {
        apiKey: "${XAI_API_KEY}",
        speakerVoiceId: "eve",
        language: "en",
        responseFormat: "mp3",
      },
    },
  },
}

{
  tts: {
    auto: "always",
    provider: "xiaomi",
    providers: {
      xiaomi: {
        apiKey: "${XIAOMI_API_KEY}",
        model: "mimo-v2.5-tts",
        speakerVoice: "mimo_default",
        format: "mp3",
      },
    },
  },
}

​

Per-agent voice overrides

{
  tts: {
    auto: "always",
    provider: "elevenlabs",
    providers: {
      elevenlabs: { apiKey: "${ELEVENLABS_API_KEY}", model: "eleven_multilingual_v2" },
    },
  },
  agents: {
    list: [
      {
        id: "reader",
        tts: {
          providers: {
            elevenlabs: { speakerVoiceId: "EXAVITQu4vr4xnSDxMaL" },
          },
        },
      },
    ],
  },
}

1. tts
2. active agents.entries.*.tts
3. channel override, when the channel supports channels.<channel>.tts
4. account override, when the channel passes channels.<channel>.accounts.<id>.tts
5. local /tts preferences for this host
6. inline [[tts:...]] directives when model overrides are enabled

{
  tts: {
    provider: "openai",
    providers: {
      openai: { apiKey: "${OPENAI_API_KEY}", model: "gpt-4o-mini-tts" },
    },
  },
  channels: {
    feishu: {
      accounts: {
        english: {
          tts: {
            providers: {
              openai: { speakerVoice: "shimmer" },
            },
          },
        },
      },
    },
  },
}

​

Personas

​

Minimal persona

{
  tts: {
    auto: "always",
    persona: "narrator",
    personas: {
      narrator: {
        label: "Narrator",
        provider: "elevenlabs",
        providers: {
          elevenlabs: {
            speakerVoiceId: "EXAVITQu4vr4xnSDxMaL",
            modelId: "eleven_multilingual_v2",
          },
        },
      },
    },
  },
}

​

Full persona (provider-specific shaping)

{
  tts: {
    auto: "always",
    persona: "alfred",
    personas: {
      alfred: {
        label: "Alfred",
        description: "Dry, warm British butler narrator.",
        provider: "google",
        fallbackPolicy: "preserve-persona",
        providers: {
          google: {
            model: "gemini-3.1-flash-tts-preview",
            speakerVoice: "Algieba",
            promptTemplate: "audio-profile-v1",
          },
          openai: { model: "gpt-4o-mini-tts", speakerVoice: "cedar" },
          elevenlabs: {
            speakerVoiceId: "voice_id",
            modelId: "eleven_multilingual_v2",
            seed: 42,
            voiceSettings: {
              stability: 0.65,
              similarityBoost: 0.8,
              style: 0.25,
              useSpeakerBoost: true,
              speed: 0.95,
            },
          },
        },
      },
    },
  },
}

​

Persona resolution

1. /tts persona <id> local preference, if set.
2. tts.persona, if set.
3. No persona.

1. Direct overrides (CLI, gateway, Talk, allowed TTS directives).
2. /tts provider <id> local preference.
3. Active persona’s provider.
4. tts.provider.
5. Registry auto-select.

1. tts.providers.<id>
2. tts.personas.<persona>.providers.<id>
3. Trusted request overrides
4. Allowed model-emitted TTS directive overrides

​

Custom persona shaping

​

Fallback policy

​

Model-driven directives

Here you go.

[[tts:speakerVoiceId=pMsXgVXv3BLzUgSXRplE model=eleven_v3 speed=1.1]]
[[tts:text]](laughs) Read the song once more.[[/tts:text]]

• provider (registered provider id; requires allowProvider: true)
• speakerVoice / speakerVoiceId (legacy aliases: voice, voiceName, voice_name, google_voice, voiceId)
• model / google_model
• stability, similarityBoost, style, speed, useSpeakerBoost
• vol / volume (MiniMax volume, (0, 10])
• pitch (MiniMax integer pitch, −12 to 12; fractional values are truncated)
• emotion (Volcengine emotion tag)
• applyTextNormalization (auto|on|off)
• languageCode (ISO 639-1)
• seed

{ messages: { tts: { modelOverrides: { enabled: false } } } }

{ messages: { tts: { modelOverrides: { enabled: true, allowProvider: true, allowSeed: false } } } }

​

Slash commands

/tts off | on | status
/tts chat on | off | default
/tts latest
/tts provider <id>
/tts persona <id> | off
/tts limit <chars>
/tts summary off
/tts audio <text>

• /tts on writes the local TTS preference to always; /tts off writes it to off.
• /tts chat on|off|default writes a session-scoped auto-TTS override for the current chat.
• /tts persona <id> writes the local persona preference; /tts persona off clears it.
• /tts latest reads the latest assistant reply from the current session transcript and sends it as audio once. It stores only a hash of that reply on the session entry to suppress duplicate voice sends.
• /tts audio generates a one-off audio reply (does not toggle TTS on).
• /tts limit <chars> accepts 100–4096 (4096 is the Telegram caption/message max); values outside that range are rejected.
• limit and summary are stored in local prefs, not the main config.
• /tts status includes fallback diagnostics for the latest attempt — Fallback: <primary> -> <used>, Attempts: ..., and per-attempt detail (provider:outcome(reasonCode) latency).
• /status shows the active TTS mode plus configured provider, model, voice, and sanitized custom endpoint metadata when TTS is enabled.

​

Per-user preferences

​

Output formats

• Feishu / WhatsApp transcoding: when a voice-note reply lands as MP3/WebM/WAV/M4A or another likely audio file, the channel plugin transcodes it to 48 kHz Ogg/Opus with ffmpeg (libopus, 64 kbps) before sending the native voice message. WhatsApp sends the result through the Baileys audio payload with ptt: true and audio/ogg; codecs=opus. On transcode failure: Feishu catches the error and falls back to sending the original file as a plain attachment; WhatsApp has no fallback, so the send itself fails rather than posting an incompatible PTT payload.
• MiniMax: MP3 (speech-2.8-hd model, 32 kHz sample rate) for normal audio attachments; transcoded to 48 kHz Opus with ffmpeg for channel-advertised voice-note targets.
• Xiaomi MiMo: MP3 by default, or WAV when configured; transcoded to 48 kHz Opus with ffmpeg for channel-advertised voice-note targets.
• Local CLI: uses the configured outputFormat. Voice-note targets are converted to Ogg/Opus and telephony output is converted to raw 16 kHz mono PCM with ffmpeg.
• Google Gemini: returns raw 24 kHz PCM. OpenClaw wraps it as WAV for audio attachments, transcodes it to 48 kHz Opus for voice-note targets, and returns PCM directly for Talk/telephony.
• Gradium: WAV for audio attachments, Opus for voice-note targets, and ulaw_8000 at 8 kHz for telephony.
• Inworld: MP3 for normal audio attachments, native OGG_OPUS for voice-note targets, and raw PCM at 22050 Hz for Talk/telephony.
• xAI: MP3 by default; audio-file synthesis may use mp3, wav, pcm, mulaw, or alaw for both buffered and streaming output. Voice-note targets use MP3 for streaming and buffered fallback because xAI’s pcm, mulaw, and alaw outputs are headerless raw audio. Buffered synthesis uses xAI’s batch REST /v1/tts endpoint; textToSpeechStream uses native wss://api.x.ai/v1/tts. This is not the realtime voice contract. Native Opus voice-note format is not supported.
• Microsoft: uses microsoft.outputFormat (default audio-24khz-48kbitrate-mono-mp3).
  • The bundled transport accepts an outputFormat, but not all formats are available from the service.
  • Output format values follow Microsoft Speech output formats (including Ogg/WebM Opus).
  • Telegram sendVoice accepts OGG/MP3/M4A; use OpenAI/ElevenLabs if you need guaranteed Opus voice messages.
  • If the configured Microsoft output format fails, OpenClaw retries with MP3.
  • When no explicit voice override is set and the default English voice is used, OpenClaw auto-switches to a Chinese neural voice (zh-CN-XiaoxiaoNeural, zh-CN locale) if the reply text is CJK-dominant.

​

Auto-TTS behavior

• Skips TTS if the reply already contains structured media.
• Skips very short replies (under 10 chars).
• Summarizes long replies when summaries are enabled, using summaryModel (or agents.defaults.model.primary).
• Attaches the generated audio to the reply.
• In mode: "final", still sends audio-only TTS for streamed final replies after the text stream completes; the generated media goes through the same channel media normalization as normal reply attachments.

• Summary on (default) and a summary model is available: summarizes the text to roughly maxLength chars, then synthesizes the summary.
• Summary off, summarization fails, or no API key is available for the summary model: truncates the text to maxLength chars and synthesizes the truncated text.

Reply -> TTS enabled?
  no  -> send text
  yes -> has media / short?
          yes -> send text
          no  -> length > limit?
                   no  -> TTS -> attach audio
                   yes -> summary enabled and available?
                            no  -> truncate -> TTS -> attach audio
                            yes -> summarize -> TTS -> attach audio

​

Field reference

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Agent tool

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Gateway RPC

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Service links

• OpenAI text-to-speech guide
• OpenAI Audio API reference
• Azure Speech REST text-to-speech
• Azure Speech provider
• ElevenLabs Text to Speech
• ElevenLabs Authentication
• Gradium
• Inworld TTS API
• MiniMax T2A v2 API
• Volcengine TTS HTTP API
• Xiaomi MiMo speech synthesis
• node-edge-tts
• Microsoft Speech output formats
• xAI text to speech

​

Related

• Media overview
• Music generation
• Video generation
• Slash commands
• Voice call plugin