helix4u/f5-tts

f5-tts

Use this skill when the task is specifically about the user's local F5 TTS server or when you need to choose a voice profile directly instead of relying on Hermes' default text_to_speech configuration.

Core workflow

1. Check the service first with GET /health.
2. Read the base URL from tts.f5.base_url in ~/.hermes/config.yaml when available. Default to http://localhost:8081.
3. Use the already-loaded environment variable F5TTS_SECRET_KEY when you need to authenticate directly.
4. Generate a short-lived HS256 bearer token from that env value.
5. Call GET /api/v1/voices/list to discover valid voice_profile names instead of guessing.
6. Call POST /api/v1/tts/synthesize with exact user text plus the selected voice_profile.
7. Save the returned WAV bytes to disk and return the file path or MEDIA: tag as needed.

Preferred behavior

• Prefer the built-in Hermes text_to_speech tool when the user simply wants speech output and the configured default voice is fine.
• Prefer direct F5 API use when the user wants to inspect voices, pick a specific cloned voice, debug the local TTS service, or bypass Hermes' default provider selection.
• Preserve the user's text exactly unless they asked for rewriting.
• For long text, keep the FastAPI request body within the service limit by chunking and stitching rather than relaxing validation.
• Do not ask the user for the secret key if F5TTS_SECRET_KEY is already present in the environment.

Long text

• The local F5 FastAPI endpoint accepts text up to 1000 characters per request.
• For text longer than that, split on sentence boundaries when possible.
• If a sentence still exceeds the limit, split on whitespace, then hard-split only as a last resort.
• Synthesize each chunk separately and concatenate the WAV files in order.
• For Telegram voice bubbles, convert the final WAV to OGG Opus after stitching.

Failure handling

• If /health fails, report that the local F5 container is unavailable before trying anything else.
• If auth fails, first check whether F5TTS_SECRET_KEY is already present in the environment and use it before asking the user for anything.
• If auth still fails after using the env var, verify F5TTS_SECRET_KEY matches the FastAPI container SECRET_KEY.
• If a requested voice is missing, list available voices from /api/v1/voices/list.
• If synthesis fails on long text, retry with shorter chunks instead of sending a larger single request.

Reference file

• Load references/api.md when you need exact endpoint shapes, token generation snippets, or direct request examples.