# Soniox > Streaming text-to-speech with Soniox. Source: https://polvallverdu.github.io/pipedog/docs/services/tts/soniox/ ## Overview [#overview] `SonioxTTSService` streams text to Soniox's real-time TTS WebSocket and yields PCM audio, with keepalive and stream reuse across turns. Pipecat's documentation for the same service. `packages/soniox/src`. ## Installation [#installation] ```bash bun add @pipedog/soniox ``` ## Prerequisites [#prerequisites] * A [Soniox](https://soniox.com) account and API key, passed as `apiKey` (the examples read `SONIOX_API_KEY`). ## SonioxTTSService [#sonioxttsservice] ### Configuration [#configuration] | Option | Type | Required | Description | |---|---|---|---| | `apiKey` | `string` | yes | Soniox API key for authentication. Create API keys at https://console.soniox.com. | | `url` | `string \| undefined` | no | WebSocket URL for the Soniox TTS endpoint. | | `audioFormat` | `string \| undefined` | no | Output audio format. Defaults to "pcm_s16le", which matches the downstream audio pipeline. | | `settings` | `SonioxTTSSettings \| null \| undefined` | no | Runtime-updatable settings. | | `textAggregationMode` | `TextAggregationMode \| null \| undefined` | no | How to aggregate incoming text before synthesis. Defaults to `TextAggregationMode.SENTENCE`. | | `name` | `string \| null \| undefined` | no | Custom name; defaults to `ClassName#count`. | | `taskManager` | `BaseTaskManager \| null \| undefined` | no | Task manager for handling tasks. | | `enableDirectMode` | `boolean \| undefined` | no | Process frames immediately instead of using internal queues. | | `metrics` | `FrameProcessorMetrics \| null \| undefined` | no | Optional metrics collector for this processor. | | `reconnectBackoffMinWait` | `number \| undefined` | no | Minimum time, in seconds, to wait between reconnection attempts. | | `reconnectBackoffMaxWait` | `number \| undefined` | no | Maximum time, in seconds, to wait between reconnection attempts. | | `reconnectOnError` | `boolean \| undefined` | no | Whether to automatically reconnect on connection errors. | | `wsCloseTimeout` | `number \| undefined` | no | Maximum time, in seconds, to wait for the peer to acknowledge the websocket closing handshake before dropping the connection. Applied to connections opened through `_websocketConnect()`. Increase it for peers that need longer to complete a graceful close. | | `wsSendTimeout` | `number \| null \| undefined` | no | Maximum time, in seconds, a single send may wait on a peer that has stopped reading before the connection is dropped and the send throws `ConnectionClosedError`. Applied to connections opened through `_websocketConnect()`. Pass `null` to wait indefinitely. Defaults to `WS_SEND_TIMEOUT`. | | `pushTextFrames` | `boolean \| undefined` | no | Whether to push TextFrames and LLMFullResponseEndFrames. | | `pushStopFrames` | `boolean \| undefined` | no | Whether to automatically push TTSStoppedFrames. | | `pushStartFrame` | `boolean \| undefined` | no | Whether to automatically create audio contexts and push TTSStartedFrames. When true, the base class handles `createAudioContext` and yields `TTSStartedFrame` before each synthesis call, so `runTts` implementations do not need to. | | `stopFrameTimeoutS` | `number \| undefined` | no | Idle time before pushing TTSStoppedFrame when pushStopFrames is true. | | `pushSilenceAfterStop` | `boolean \| undefined` | no | Whether to push silence audio after TTSStoppedFrame. | | `silenceTimeS` | `number \| undefined` | no | Duration of silence to push when pushSilenceAfterStop is true. | | `pauseFrameProcessing` | `boolean \| undefined` | no | Whether to hold incoming frames after a turn until its audio contexts end. Needed by services whose audio doesn't carry its request's context ID. | | `maxConsecutiveZeroAudioContexts` | `number \| undefined` | no | How many consecutive TTS contexts may complete without producing any audio before the service is reported unable to do its job. Catches a provider that accepts requests and stays silent — an unknown voice ID, say — which no error ever surfaces. Every silent context reports an error the service can carry on from, whatever the limit is; on reaching the limit the service reports a permanent error instead, stops being given work, and the pipeline worker applies its `ProcessorUnusablePolicy`. Set to 0 to report silent contexts without ever writing the service off. | | `appendTrailingSpace` | `boolean \| undefined` | no | Whether to append a trailing space to text before sending to TTS. This helps prevent some TTS services from vocalizing trailing punctuation (e.g., "dot"). Only applied in sentence aggregation mode; when streaming tokens, the incoming text's own whitespace is preserved. | | `sampleRate` | `number \| null \| undefined` | no | Output sample rate for generated audio. | | `skipTextTypes` | `string[] \| null \| undefined` | no | List of text types that should not be spoken. | | `textTransforms` | `[string, TextTransform][] \| null \| undefined` | no | A list of TextTransforms to transform text just before sending it to TTS. Each TextTransform takes the aggregated text and its type, and returns the transformed text. To register, provide a list of tuples of `[textType \| "*", transformFunction]`. | | `transportDestination` | `string \| null \| undefined` | no | Destination for generated audio frames. | | `reuseContextIdWithinTurn` | `boolean \| undefined` | no | Whether the service should reuse context IDs within the same turn. | | `audioCache` | `TTSAudioCacheStore \| null \| undefined` | no | Where to keep synthesized audio for reuse (e.g. a shared `TTSAudioCache`). Text whose audio is in the cache is served from it, with no request to the provider. Lines get there through `warmAudioCache()`, and also from live synthesis when `cacheSynthesizedAudio` allows it. Only services that yield their audio from `runTts` (HTTP and streaming-RPC services, see `supportsAudioCache`) use it, and only in sentence aggregation mode. Defaults to null (no cache). pipedog only. | | `cacheSynthesizedAudio` | `boolean \| ((text: string) => boolean) \| undefined` | no | Whether audio synthesized live is stored in `audioCache`, or a function that decides per text. Defaults to false: only warmed lines are stored, since a generated reply can repeat what the user said. pipedog only. | | `audioCacheNamespace` | `string \| undefined` | no | Extra part of the cache key, for constructor options that change the audio but are not in `settings`. pipedog only. | ### Settings [#settings] Runtime-updatable settings, passed as `settings: new SonioxTTSService.Settings({...})`. Settings you leave out keep their defaults. | Setting | Default | Description | | ------------------- | ------------- | ----------------------------- | | `model` | `"tts-rt-v2"` | Soniox TTS model. | | `voice` | `"Bryce"` | Voice. | | `language` | `Language.EN` | Language. | | `speed` | | Speaking speed. | | `reduceSilence` | | Not supported by every model. | | `clientReferenceId` | | Your own reference. | ### Usage [#usage] ```ts title="tts.ts" import { SonioxTTSService } from "@pipedog/soniox/tts"; const tts = new SonioxTTSService({ apiKey: process.env.SONIOX_API_KEY ?? "", settings: new SonioxTTSService.Settings({ voice: "Adrian", speed: 1.1 }), }); ``` ### Notes [#notes] * `sampleRate` must be one of `VALID_SAMPLE_RATES`. ## Runtimes [#runtimes] | Runtime | Works | What it needs | | ------------------ | ----- | ------------- | | Bun | ✅ yes | Nothing. | | Node.js | ✅ yes | Nothing. | | Deno | ✅ yes | Nothing. | | Cloudflare Workers | ✅ yes | Nothing. | Generated from `pipecat.runtimes` and `pipecat.compat` in `packages/soniox/package.json`: ✅ means the compat smoke test passes on that runtime. The service uses `fetch` and the global `WebSocket` (through core's `websocketConnect`, which sends the auth header on the handshake on Cloudflare Workers too). Pass no SDK; nothing is Node-only.