Adding a New TTS Backend¶

"""My Custom TTS backend — description of what it is."""

from __future__ import annotations

import json
import os
import urllib.error
import urllib.request

from .voices import to_kokoro  # if your backend uses Kokoro voice names

MY_PORT = int(os.environ.get("MY_BACKEND_PORT", "9999"))
MY_URL = f"http://localhost:{MY_PORT}"


class MyBackend:
    name = "my-backend"
    priority = 25  # between kokoro (20) and pocket-tts (30)

    def is_available(self) -> bool:
        """Check if the service is reachable."""
        try:
            req = urllib.request.Request(f"{MY_URL}/health", method="GET")
            resp = urllib.request.urlopen(req, timeout=1.0)
            return 200 <= resp.status < 300
        except (urllib.error.URLError, OSError, ValueError):
            return False

    def ensure_running(self) -> bool:
        """Start the service if possible, then check availability.

        If your backend can't auto-start, just return is_available().
        """
        return self.is_available()

    def generate(self, text: str, voice: str, speed: float) -> bytes:
        """Generate WAV audio from text.

        Args:
            text: The text to speak
            voice: Voice name in canonical Kokoro form (e.g., "af_heart")
            speed: Speech speed (1.0 = normal). Ignore if unsupported.

        Returns:
            Raw WAV audio bytes.
        """
        voice = to_kokoro(voice)
        payload = json.dumps({"text": text, "voice": voice}).encode()
        req = urllib.request.Request(
            f"{MY_URL}/synthesize",
            data=payload,
            headers={"Content-Type": "application/json"},
        )
        resp = urllib.request.urlopen(req, timeout=60)
        return resp.read()

def _registry() -> dict[str, type[TTSBackend]]:
    from .fish_speech import FishSpeechBackend
    from .kokoro import KokoroBackend
    from .my_backend import MyBackend          # (1)!
    from .pocket_tts import PocketTTSBackend

    return {
        "kokoro": KokoroBackend,
        "fish-speech": FishSpeechBackend,
        "my-backend": MyBackend,               # (2)!
        "pocket-tts": PocketTTSBackend,
    }