relayspeech 0.1.0

Official Python SDK for the Relay Speech (OpenTTS) API — one client, all TTS providers.

Relay Speech — Python SDK

Official Python client for the Relay Speech (OpenTTS) gateway. One API, all TTS providers — Cartesia, ElevenLabs, Sarvam, and more.

pip install relayspeech

Quickstart

from relayspeech import RelaySpeech

client = RelaySpeech(
    api_key="rs_live_...",            # your Relay Speech key
    provider="cartesia",              # default provider
    provider_api_key="sk-cartesia-..."
)

audio = client.tts.bytes(
    text="Hello from Relay Speech.",
    voice_id="694f9389-aac1-45b6-b726-9d9369183238",
)
open("hello.pcm", "wb").write(audio)

Environment variables (RELAY_SPEECH_API_KEY, CARTESIA_API_KEY, ELEVENLABS_API_KEY, SARVAM_API_KEY) are picked up automatically.

REST streaming

with open("out.pcm", "wb") as f:
    for chunk in client.tts.stream(text="Streaming demo.", voice_id="..."):
        f.write(chunk)

Async

from relayspeech import AsyncRelaySpeech

async with AsyncRelaySpeech(api_key="...", provider="elevenlabs",
                            provider_api_key="...") as client:
    async for chunk in await client.tts.stream(text="Hi", voice_id="..."):
        ...

WebSocket (low-latency, full duplex)

async with AsyncRelaySpeech(api_key="...", provider="cartesia",
                            provider_api_key="...") as client:
    async with client.tts.websocket() as ws:
        async for chunk in await ws.send(
            text="One sentence at a time.",
            voice_id="...",
            enable_cache=True,
        ):
            speaker.write(chunk)

Reuse the same ws for many sentences — the gateway holds the upstream provider connection open and caches each chunk independently.

Output format

from relayspeech import OutputFormat, AudioContainer, AudioEncoding

audio = client.tts.bytes(
    text="…",
    voice_id="…",
    output_format=OutputFormat(
        container=AudioContainer.WAV,
        encoding=AudioEncoding.PCM_S16LE,
        sample_rate=24000,
    ),
)

Errors

Exception	When
RelaySpeechAuthError	Invalid / missing Relay Speech key (401)
RelaySpeechProviderError	Upstream provider failed (5xx)
RelaySpeechAPIError	Any other non-2xx response
RelaySpeechConnectionError	Network / WebSocket transport failure

All inherit from RelaySpeechError.