Oma Voice

Voice Skill - Local TTS and STT via Voicebox

Scheduling

Goal

Drive the Voicebox local app through its MCP server so any MCP-aware agent can speak (TTS) or listen (STT) without invoking cloud vendors. The skill standardizes intent routing, voice profile resolution, output layout, and guardrails while voicebox itself owns the engines, voice cloning UI, captures archive, and stories editor.

Intent signature

• User asks to generate speech, narrate text, produce a voiceover, create an mp3 or wav from text.
• User wants an audio file transcribed into text, meeting notes, or a transcript.
• User asks for a voice notification when a long task completes or a workflow step is blocked.
• Another skill needs local audio generation infrastructure.

When to use

• Generating short notification audio for agent task completion or blockers.
• Producing voiceover, narration, or audio assets (mp3 or wav) for apps and content.
• Transcribing local audio files (mp3, wav, m4a, webm, flac) to Markdown.
• Comparing voice profiles by re-running the same text against different profile ids.

When NOT to use

• Cloud TTS or high-fidelity multilingual cloud voices -> out of scope; future multi-vendor extension.
• Real-time microphone dictation loop in the terminal -> use Voicebox app's built-in hotkey dictation.
• Voice cloning sample upload and profile creation -> done in the Voicebox desktop app UI.
• Video synthesis, music, sound design -> out of scope.
• Stories Editor multi-voice timeline composition -> use the Voicebox app UI.

Expected inputs

• TTS: text (<= 5000 chars per call), optional profile id, optional engine, optional language, optional output path.
• STT: audio file path (absolute or relative to $CWD), optional language hint.
• Notification: short message (<= 240 chars), profile id resolved from config.

Expected outputs

• TTS: audio file (wav — Voicebox's native TTS output format; mp3 optional via a local ffmpeg transcode) at .agents/results/voice/{timestamp}-{shortid}/output.{wav|mp3} plus manifest.json.
• STT: transcript.md at .agents/results/voice/transcripts/{timestamp}-{shortid}/ plus manifest.json.
• Notification: ephemeral playback through Voicebox; no disk write by default.

Dependencies

• Voicebox desktop app installed and running locally.
• Voicebox MCP registered (claude mcp add --transport http voicebox http://127.0.0.1:17493/mcp).
• TTS only: at least one voice profile created in the Voicebox app UI.
• TTS only: optionally pre-downloaded engine models for the selected profile.

Control-flow features

• Branches by mode (notify, asset, transcribe), language, and profile availability.
• Calls voicebox via MCP tools, with REST GET /health as the handshake probe.
• Reads input audio files and writes generated audio plus manifests.
• Caches discovered MCP tool names after the first successful tools/list.

Structural Flow

Entry

1. Detect the requested mode: notification, asset TTS, or transcription.
2. Verify Voicebox is reachable via MCP handshake or GET /health.
3. On the first run only, call MCP tools/list and cache the resolved tool names.
4. For notification or asset TTS, resolve the target voice profile id. For transcription, validate the audio input and continue without a profile.

Scenes

1. PREPARE: Validate text length, audio duration, language, output path, and profile id.
2. ACQUIRE: If a required signal is missing, run the clarification protocol once.
3. ACT: Invoke the appropriate MCP tool (TTS or STT) with the resolved parameters.
4. VERIFY: Confirm the response carries audio output or transcript content. Validate manifest fields.
5. FINALIZE: Write manifest.json alongside the output. Report the path or transcript to the user.

Transitions

• If voicebox is unreachable, surface the install or launch hint and exit. Do not attempt auto-relaunch.
• If a TTS request has no usable profile, point the user at the Voicebox app UI to create a profile, then exit. A transcription request never needs a profile.
• If a TTS request exceeds 5000 chars, ask whether to truncate or split. Do not auto-chunk in v1.
• If an STT input exceeds 30 minutes, ask whether to proceed. Do not auto-split.
• If the selected engine model is not loaded, ask the user before triggering a download.

Failure and recovery

Exit

• Success: audio file or transcript exists with a complete manifest, and the path is reported.
• Partial success: output exists but a guardrail warning is surfaced (length, disk, model fallback).
• Failure: no output, the blocker (auth, profile, engine, network) is explicit.

Logical Operations

Actions

Tools and instruments

• Voicebox MCP server at http://127.0.0.1:17493/mcp.
• REST surface for health and audio retrieval (GET /health, GET /audio/{generation_id}).
• Resource references: voice matrix, prompt tips, execution protocol, checklist.

Canonical command path

# 1. MCP handshake or REST health
GET http://127.0.0.1:17493/health  ->  200 OK

# 2. Discover tool names on first run
MCP tools/list                      ->  cache real names

# 3. TTS only: resolve profile
MCP voicebox_list_profiles          ->  pick profile by name or config default

# 4. Generate or transcribe (STT skips profile lookup and model-status check)
MCP voicebox_speak     { text, profile, language?, engine?, personality? }
MCP voicebox_transcribe { audio_path | audio_base64, language?, model? }

# 5. Fetch the generated audio (MCP has no save-to-disk; TTS output is wav)
GET http://127.0.0.1:17493/audio/{generation_id}  ->  wav bytes

# 6. Persist output + manifest
.agents/results/voice/<timestamp>-<shortid>/output.wav + manifest.json
.agents/results/voice/transcripts/<timestamp>-<shortid>/transcript.md + manifest.json

MCP tool mapping (verified against Voicebox 0.5.0)

Tools not exposed via MCP (REST only): model status (GET /models/status), audio file serving (GET /audio/{generation_id}), per-version audio (GET /audio/version/{version_id}). The skill calls those over loopback HTTP when needed.

Notes on voicebox_speak:

• Required: text. Optional: profile, engine, language, personality (bool).
• Audio plays on the user speakers and is saved to the Captures / History panel automatically. There is no save_to_disk toggle on the MCP tool itself; to persist a local copy, fetch GET /audio/{generation_id} (Voicebox TTS always stores wav).
• Without a default profile set in Voicebox Settings, profile= is required.

Notes on voicebox_transcribe:

• Accepts exactly one of audio_base64 or audio_path (loopback only). Optional language, model.