Voice Bridge

Voice Bridge

[PyPI] [CI]

Multi-engine text-to-speech for AI coding assistants. Speaks responses aloud from Claude Code, Cursor, or VS Code via a Claude Code plugin, MCP server, or CLI pipe.

pip install ai-voice-bridge[edge]   # Install with free edge-tts enginevoice-bridge test                   # Verify audio outputvoice-bridge on                     # Enable always-on mode (optional)

Features

• Free by default -- edge-tts uses Microsoft Neural voices, no API key needed
• 5 engines -- edge-tts, ElevenLabs, Kokoro (local ONNX), macOS say, espeak-ng
• Text safety filter -- strips code blocks, secrets, file paths, URLs, and markdown before speaking
• Claude Code plugin -- Stop hook speaks responses automatically, MCP server for tool-based control
• Voice discovery -- browse, filter by gender/locale, and preview voices interactively

Prerequisites

Voice Bridge is a Python package that plays audio on your local machine. It requires:

Audio player fallback order: macOS uses afplay (always available). Linux tries mpv then ffplay. Windows tries ffplay then mpv.

Not supported: headless servers, Docker containers, SSH sessions, and CI runners typically lack audio output. Voice Bridge will install and run the MCP server, but speak commands will fail silently without an audio player and sound hardware.

Quick Start

Install

# Recommended: edge-tts (free, 400+ voices)pip install ai-voice-bridge[edge]
# Or with all enginespip install ai-voice-bridge[all]
# Or minimal (macOS say / Linux espeak only)pip install ai-voice-bridge

Test

voice-bridge test          # Speak a test phrasevoice-bridge engines       # List available enginesvoice-bridge setup         # Interactive setup wizard

The setup wizard walks you through: detecting installed engines, testing audio output, optionally entering an ElevenLabs API key (if the SDK is installed), writing default state, and showing Claude Code integration options.

Use

# Pipe text to speechecho "Hello world" | vb-speak
# Choose an engineecho "Hello" | vb-speak --engine edge-ttsecho "Hello" | vb-speak --engine say
# Modesvoice-bridge on            # Always-on: every AI response spokenvoice-bridge off           # Off: use "speak" keyword for single responsesvoice-bridge status        # Show current mode and engine

Claude Code Integration

Option 1: Install as a Plugin (Recommended)

claude plugin marketplace add Tomorrow-You/voice-bridgeclaude plugin install voice-bridge@voice-bridge

This installs the plugin with a Stop hook (auto-speaks responses), the /speak skill, and the MCP server. Auto-installs ai-voice-bridge[edge,mcp] on first session.

Option 2: Manual Hook Setup

Add to your .claude/settings.json:

{  "hooks": {    "Stop": [      {        "hooks": [          {            "type": "command",            "command": "bash -c 'VB_HOOK=$(python3 -c \"import voice_bridge; import pathlib; print(pathlib.Path(voice_bridge.__file__).parent / \\\"integrations\\\" / \\\"claude_hook.sh\\\")\" 2>/dev/null) && [ -f \"$VB_HOOK\" ] && bash \"$VB_HOOK\"'",            "timeout": 5          }        ]      }    ]  }}

Then add to your CLAUDE.md:

## Voice Bridge (TTS)- **NEVER** use `<speak>` tags unless the user's message starts with "speak"- When user starts with "speak", wrap your ENTIRE response in `<speak>...</speak>` tags- Strip the "speak" keyword before processing- Inside tags, write naturally -- no markdown, code blocks, or file paths

Option 2: Always-On Mode

Skip the <speak> tag convention entirely:

voice-bridge on

Now every Claude response is spoken automatically. Toggle off with voice-bridge off.

Hook Details

The Stop hook runs in the background so it doesn't block Claude Code. It:

• Extracts text from <speak> tags (single-turn mode) or the full response (always-on mode)
• Truncates to 2,000 characters before speaking
• Uses a fallback chain: configured engine > espeak > say
• Logs to ~/.voice-bridge/voice-bridge.log (auto-rotated at 1MB, keeps 2 backups)
• Runs vb-speak --stream for sentence-by-sentence playback

Engines

When engine is set to auto (default), Voice Bridge picks the first available in this order: edge-tts > say > espeak > kokoro > elevenlabs. ElevenLabs is only considered "available" if the SDK is installed AND a valid API key is configured -- it will never be auto-selected without credentials.

Discovering Voices

voice-bridge voices              # List voices for current enginevoice-bridge voices edge-tts     # List voices for a specific engine
# Filter by gender and/or localevoice-bridge voices edge-tts --gender Female --locale en-US
# Preview a specific voicevoice-bridge voices edge-tts --preview en-US-AriaNeural
# Interactively audition voices (next/select/quit after each)voice-bridge voices edge-tts --gender Female --locale en-US --preview
# Random sample of 3 voicesvoice-bridge voices edge-tts --sample 3 --preview

Filtering options: --gender (Male/Female) works with edge-tts and kokoro. --locale (e.g. en-US, en-GB) works with edge-tts and say. --sample N picks N random voices. All combine with --preview for interactive audition.

ElevenLabs preview uses free pre-recorded samples when available (no API credits consumed).

Switching Engines

voice-bridge engine edge-tts     # Free neural voicesvoice-bridge engine elevenlabs   # Premium cloudvoice-bridge engine kokoro       # Local offlinevoice-bridge engine say          # macOS built-invoice-bridge engine espeak       # Linux built-invoice-bridge engine auto         # Best available (default)

ElevenLabs Setup

pip install ai-voice-bridge[elevenlabs]voice-bridge setup  # Prompts for your ElevenLabs API key# Or manually: create ~/.voice-bridge/.env with ELEVENLABS_API_KEY=your-keyvoice-bridge engine elevenlabsvoice-bridge test

Kokoro Setup (Offline)

pip install ai-voice-bridge[kokoro]# Download model files (~200MB) from:# https://github.com/thewh1teagle/kokoro-onnx/releases/tag/model-files-v1.0# Place in: ~/.voice-bridge/models/ (or $VOICE_BRIDGE_HOME/models/)voice-bridge engine kokorovoice-bridge test

Configuration

Voice Bridge stores configuration in ~/.voice-bridge/ (macOS), ~/.local/share/voice-bridge/ (Linux, respects XDG_DATA_HOME), or %APPDATA%\voice-bridge\ (Windows).

Override with the VOICE_BRIDGE_HOME environment variable.

State Variables

The .state file is a shell-sourceable key-value file. All values are optional — defaults apply if unset.

Text Safety Filter

Before any text reaches the TTS engine, Voice Bridge strips:

• Code blocks (fenced ``` and inline `)
• Secrets: OpenAI/Anthropic keys (sk-...), GitHub tokens (ghp_, gho_), AWS keys (AKIA...), PEM private keys, 64+ char hex strings
• File paths: Unix (/Users/..., /home/...) and Windows (C:\Users\...)
• URLs: http:// and https://
• Markdown: headers, bold/italic markers, list bullets, table rows

Text is truncated to 4,000 characters at the nearest sentence boundary (. ). The Claude hook applies a separate 2,000 character limit before passing text to vb-speak.

CLI Reference

# Controlvoice-bridge on              # Always-on modevoice-bridge off             # Single-turn mode (default)voice-bridge status          # Show mode, engine, configvoice-bridge test            # Test audio outputvoice-bridge engines         # List all engines with install statusvoice-bridge setup           # Interactive setup wizard
# Engine configvoice-bridge engine [name]   # Get/set enginevoice-bridge voice [id]      # Set voice for current enginevoice-bridge voices [engine] # List available voicesvoice-bridge speed [val]     # Set engine speed (see below)
# Voice discoveryvoice-bridge voices edge-tts --gender Female --locale en-US  # Filtervoice-bridge voices edge-tts --preview en-US-AriaNeural      # Preview onevoice-bridge voices edge-tts --gender Female --preview       # Interactivevoice-bridge voices edge-tts --sample 3 --preview            # Random sample
# Pipe to speechecho "text" | vb-speak                    # Default engineecho "text" | vb-speak --engine edge-tts  # Specific engineecho "text" | vb-speak --voice Aria       # Override voice for this callecho "text" | vb-speak --stream           # Stream sentence-by-sentenceecho "text" | vb-speak --dry-run          # Print filtered text only

Streaming mode (--stream): reads stdin, splits text at sentence boundaries (. , ! , ? ), and speaks each sentence as it completes. For edge-tts, sentences are queued so the next one generates while the current one plays.

Speed Control

Each engine accepts a different speed format:

Speed applies to whichever engine is currently active. Check with voice-bridge speed (no value).

MCP Server

Voice Bridge includes an MCP (Model Context Protocol) server so any MCP-compatible tool can speak text aloud.

npm shim (npx ai-voice-bridge): The npm package is a thin wrapper that auto-installs the Python package. It requires Python 3.10+ and pip on your PATH. On startup it checks for audio players and warns if none are found. See Prerequisites for full requirements.

Setup with Claude Desktop

Add to your claude_desktop_config.json:

{  "mcpServers": {    "voice-bridge": {      "command": "python3",      "args": ["-m", "voice_bridge.mcp.server"]    }  }}

Or after npm publish, use the npm shim:

{  "mcpServers": {    "voice-bridge": {      "command": "npx",      "args": ["ai-voice-bridge"]    }  }}

Setup with Cursor / VS Code

Add the same MCP server config in your editor's MCP settings. The config format is the same as Claude Desktop.

Setup with Claude Code

claude mcp add voice-bridge -- python3 -m voice_bridge.mcp.server

MCP Tools

Install with MCP support

pip install ai-voice-bridge[mcp]

This installs the voice-bridge-mcp command as an alternative to python3 -m voice_bridge.mcp.server.

Development

git clone https://github.com/Tomorrow-You/voice-bridge.gitcd voice-bridgepython3 -m venv .venv && source .venv/bin/activatepip install -e ".[all,dev]"pytest

License

MIT. See LICENSE for details.

The edge-tts optional dependency is licensed under GPL-3.0. It is not included in the base install.