Speech Settings

Speech Introduction

The Speech Configuration includes settings for both Speech-to-Text (STT) and Text-to-Speech (TTS) under a unified speech: section. Additionally, there is a new speechTab menu for user-specific settings.

See Also: For detailed YAML configuration schema and all available options, see the Speech Object Structure documentation.

Environment Variables

When using cloud-based STT/TTS services, you'll need to set API keys in your .env file:

# Speech-to-Text API key (e.g., OpenAI Whisper)
STT_API_KEY=your-stt-api-key

# Text-to-Speech API key (e.g., OpenAI TTS, ElevenLabs)
TTS_API_KEY=your-tts-api-key

These keys are then referenced in your librechat.yaml configuration using ${STT_API_KEY} and ${TTS_API_KEY}.

Self-hosted engines need an allowedAddresses entry

Both speech.stt and speech.tts accept an allowedAddresses list. Outbound speech requests are validated against their resolved IP and blocked from reaching private, loopback, and link-local address space, so a self-hosted engine on localhost, a LAN address, or a Docker service name is unreachable until you list it:

speech:
  tts:
    allowedAddresses:
      - 'host.docker.internal:8080'
    localai:
      url: 'http://host.docker.internal:8080/tts'
      # ...

Entries are bare host:port pairs: no scheme or path, port required, IPv6 bracketed as [::1]:8080, and IP literals must be private. Public cloud endpoints such as OpenAI, Azure, and ElevenLabs need no entry. The guard works on the resolved IP, not the hostname, so a cloud endpoint reached over Private Link, private DNS, or a VPN resolves into private address space and does need its exact host:port listed like any other private target. The same field and rules apply under speech.stt. See SSRF protection for the full entry format.

Speech Tab (optional)

The speechTab menu provides customizable options for conversation and advanced modes, as well as detailed settings for STT and TTS. This will set the default settings for users

Use browser for built-in browser speech or external for a server-side provider configured below. Older provider-specific defaults remain accepted for compatibility and are normalized to external; if the matching external service is unavailable, LibreChat falls back to browser.

example:

speech:
  speechTab:
    conversationMode: true
    advancedMode: false
    speechToText:
      engineSTT: "external"
      languageSTT: "English (US)"
      autoTranscribeAudio: true
      decibelValue: -45
      autoSendText: 0
    textToSpeech:
      engineTTS: "external"
      voice: "alloy"
      languageTTS: "en"
      automaticPlayback: true
      playbackRate: 1.0
      cacheTTS: true

speechTab sets the initial values users see; each remains changeable per user in the speech settings tab.

Top-level keys:

speechToText subkeys:

textToSpeech subkeys:

STT (Speech-to-Text)

The Speech-to-Text (STT) feature converts spoken words into written text. To enable STT, click on the STT button (near the send button) or use the key combination ++Ctrl+Alt+L++ to start the transcription.

Available STT Services

• Local STT
  • Browser-based
  • Whisper (tested on LocalAI)
• Cloud STT
  • OpenAI Whisper
  • Azure Whisper
  • Other OpenAI-compatible STT services

Configuring Local STT

• Browser-based

  No setup required. Ensure the "Speech To Text" switch in the speech settings tab is enabled and "Browser" is selected in the engine dropdown.

• Whisper Local

  Requires a local Whisper instance.

speech:
  stt:
    openai:
      url: 'http://host.docker.internal:8080/v1/audio/transcriptions'
      model: 'whisper'

Configuring Cloud STT

• OpenAI Whisper

speech:
  stt:
    openai:
      apiKey: '${STT_API_KEY}'
      model: 'whisper-1'

• Azure Whisper

speech:
  stt:
    azureOpenAI:
      instanceName: 'instanceName'
      apiKey: '${STT_API_KEY}'
      deploymentName: 'deploymentName'
      apiVersion: 'apiVersion'

• OpenAI compatible

Refer to the OpenAI Whisper section, adjusting the url and model as needed.

example

speech:
  stt:
    openai:
      url: 'http://host.docker.internal:8080/v1/audio/transcriptions'
      model: 'whisper'

TTS (Text-to-Speech)

The Text-to-Speech (TTS) feature converts written text into spoken words. Various TTS services are available:

Available TTS Services

• Local TTS
  • Browser-based
  • Piper (tested on LocalAI)
  • Coqui (tested on LocalAI)
• Cloud TTS
  • OpenAI TTS
  • Azure OpenAI
  • ElevenLabs
  • Other OpenAI/ElevenLabs-compatible TTS services

Configuring Local TTS

• Browser-based

No setup required. Ensure the "Text To Speech" switch in the speech settings tab is enabled and "Browser" is selected in the engine dropdown.

• Piper

Requires a local Piper instance.

speech:
  tts:
    localai:
      url: "http://host.docker.internal:8080/tts"
      apiKey: "EMPTY"
      voices: [
        "en-us-amy-low.onnx",
        "en-us-danny-low.onnx",
        "en-us-libritts-high.onnx",
        "en-us-ryan-high.onnx",
      ]
      backend: "piper"

• Coqui

Requires a local Coqui instance.

speech:
  tts:
    localai:
      url: 'http://localhost:8080/v1/audio/synthesize'
      voices: ['tts_models/en/ljspeech/glow-tts', 'tts_models/en/ljspeech/tacotron2', 'tts_models/en/ljspeech/waveglow']
      backend: 'coqui'

Configuring Cloud TTS

• OpenAI TTS

speech:
  tts:
    openai:
      apiKey: '${TTS_API_KEY}'
      model: 'tts-1'
      voices: ['alloy', 'echo', 'fable', 'onyx', 'nova', 'shimmer']

• Azure OpenAI

speech:
  tts:
    azureOpenAI:
      instanceName: ''
      apiKey: '${TTS_API_KEY}'
      deploymentName: ''
      apiVersion: ''
      model: 'tts-1'
      voices: ['alloy', 'echo', 'fable', 'onyx', 'nova', 'shimmer']

• ElevenLabs

speech:
  tts:
    elevenlabs:
      apiKey: '${TTS_API_KEY}'
      model: 'eleven_multilingual_v2'
      voices: ['202898wioas09d2', 'addwqr324tesfsf', '3asdasr3qrq44w', 'adsadsa']

Additional ElevenLabs-specific parameters can be added as follows:

      voice_settings:
        similarity_boost: '' # number
        stability: '' # number
        style: '' # number
        use_speaker_boost: # boolean
      pronunciation_dictionary_locators: [''] # list of strings (array)

• OpenAI compatible

Refer to the OpenAI TTS section, adjusting the url variable as needed

example:

speech:
  tts:
    openai:
      url: 'http://host.docker.internal:8080/v1/audio/synthesize'
      apiKey: '${TTS_API_KEY}'
      model: 'tts-1'
      voices: ['alloy', 'echo', 'fable', 'onyx', 'nova', 'shimmer']

• ElevenLabs compatible

Refer to the ElevenLabs section, adjusting the url variable as needed

example:

speech:
  tts:
    elevenlabs:
      url: 'http://host.docker.internal:8080/v1/audio/synthesize'
      apiKey: '${TTS_API_KEY}'
      model: 'eleven_multilingual_v2'
      voices: ['202898wioas09d2', 'addwqr324tesfsf', '3asdasr3qrq44w', 'adsadsa']