1.0.13

The Azure speech SDK was pinned to exactly 1.38.0 since the initial
commit. It pulls in uuid <11.1.1, which carries GHSA-w5hq-g745-h8pq
(missing buffer bounds check in v3/v5/v6 when buf is provided). The
advisory covers Azure SDK 1.14.0-1.50.0; 1.51.0 clears it.

Loosened the exact pin to a caret range so future patches come in
without another PR. The SDK surface used here (SpeechConfig,
SpeechSynthesizer, ResultReason, CancellationDetails,
SpeechSynthesisOutputFormat) is unchanged in 1.51.0.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

CLAUDE.md

@@ -0,0 +1,84 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Overview
+
+`@jambonz/speech-utils` is a Node.js library providing TTS (Text-to-Speech) utilities for the jambonz CPaaS platform. It handles speech synthesis with caching through Redis and supports multiple TTS vendors.
+
+## Commands
+
+```bash
+# Run tests (requires Docker for Redis)
+npm test
+
+# Run linter
+npm run jslint
+
+# Auto-fix lint issues
+npm run jslint:fix
+
+# Generate coverage report
+npm run coverage
+```
+
+## Testing
+
+Tests use `tape` and require Redis. The test harness automatically starts/stops Redis via Docker Compose (`test/docker-compose-testbed.yaml`).
+
+Most tests are conditional based on environment variables for vendor credentials:
+- `GCP_FILE` or `GCP_JSON_KEY` - Google TTS
+- `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, `AWS_REGION` - AWS Polly
+- `MICROSOFT_API_KEY`, `MICROSOFT_REGION` - Azure TTS
+- `ELEVENLABS_API_KEY`, `ELEVENLABS_VOICE_ID`, `ELEVENLABS_MODEL_ID` - ElevenLabs
+- `OPENAI_API_KEY` - OpenAI Whisper TTS
+- And others per vendor
+
+Redis config is in `config/test.json` (port 3379).
+
+## Architecture
+
+### Entry Point
+
+`index.js` exports a factory function that takes Redis options and a logger, returning an object with these methods:
+- `synthAudio` - Main synthesis function
+- `getTtsVoices` - List available voices for a vendor
+- `purgeTtsCache` / `getTtsSize` / `addFileToCache` - Cache management
+- `getAwsAuthToken` - Token management
+
+### Core Module: `lib/synth-audio.js`
+
+The `synthAudio` function handles synthesis for all vendors. Key behaviors:
+1. **Cache check**: Generates SHA1 hash key from (vendor, language, voice, engine, model, text, instructions)
+2. **Streaming vs non-streaming**: When `JAMBONES_DISABLE_TTS_STREAMING` is not set and `renderForCaching=false`, returns `say:{params}text` format for FreeSWITCH streaming playback instead of generating files
+3. **Vendor dispatch**: Switch statement routes to vendor-specific synth functions (`synthGoogle`, `synthPolly`, `synthMicrosoft`, etc.)
+4. **Caching**: Stores audio as base64 JSON in Redis with configurable TTL (default 4 hours)
+
+### Supported Vendors
+
+google, aws/polly, microsoft/azure, nvidia (Riva), wellsaid, elevenlabs, cartesia, inworld, rimelabs, whisper (OpenAI), deepgram, resemble, custom:*
+
+### gRPC Stubs
+
+`stubs/riva/` contains generated protobuf/gRPC code for NVIDIA Riva.
+
+## Environment Variables
+
+Key configuration via env vars (see `lib/config.js`):
+- `JAMBONES_DISABLE_TTS_STREAMING` - Force non-streaming mode
+- `JAMBONES_DISABLE_AZURE_TTS_STREAMING` - Azure-specific streaming disable
+- `JAMBONES_TTS_CACHE_DURATION_MINS` - Cache TTL in minutes (default: 240)
+- `JAMBONES_TTS_TRIM_SILENCE` - Trim trailing silence from audio
+- `JAMBONES_TMP_FOLDER` - Temp folder for audio files (default: /tmp)
+- `JAMBONES_HTTP_PROXY_IP`, `JAMBONES_HTTP_PROXY_PORT` - HTTP proxy for Azure
+- `JAMBONES_AZURE_ENABLE_SSML` - Force SSML wrapper for Azure plain text
+
+## Key Dependencies
+
+- `@jambonz/realtimedb-helpers` - Redis client and hash utilities
+- `@google-cloud/text-to-speech` - Google TTS
+- `@aws-sdk/client-polly` - AWS Polly
+- `microsoft-cognitiveservices-speech-sdk` - Azure TTS
+- `@grpc/grpc-js` - gRPC for Riva
+- `openai` - OpenAI Whisper TTS
+- `bent` - HTTP client for REST-based vendors

lib/synth-audio.js

@@ -80,7 +80,9 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
   logger = logger || noopLogger;
 
   assert.ok(['google', 'aws', 'polly', 'microsoft', 'wellsaid', 'nvidia', 'elevenlabs',
-    'whisper', 'deepgram', 'rimelabs', 'cartesia', 'inworld', 'resemble'].includes(vendor) ||
+    'whisper', 'deepgram', 'deepgramflux', 'rimelabs', 'cartesia', 'gradium', 'nineninesix', 'inworld', 'resemble',
+    'murf', 'xai']
+    .includes(vendor) ||
   vendor.startsWith('custom'),
   `synthAudio supported vendors are google, aws, microsoft, nvidia and wellsaid ..etc, not ${vendor}`);
   if ('google' === vendor) {
@@ -124,9 +126,26 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
     if (!credentials.deepgram_tts_uri) {
       assert.ok(credentials.api_key, 'synthAudio requires api_key when deepgram is used');
     }
+  } else if ('deepgramflux' === vendor) {
+    // Deepgram Flux TTS (/v2/speak); the flux model rides on `voice`/`model`
+    if (!credentials.deepgram_tts_uri) {
+      assert.ok(credentials.api_key, 'synthAudio requires api_key when deepgramflux is used');
+    }
+  } else if ('xai' === vendor) {
+    assert.ok(credentials.api_key, 'synthAudio requires api_key when xai is used');
   } else if ('cartesia' === vendor) {
     assert.ok(credentials.api_key, 'synthAudio requires api_key when cartesia is used');
     assert.ok(credentials.model_id, 'synthAudio requires model_id when cartesia is used');
+  } else if ('gradium' === vendor) {
+    assert.ok(voice, 'synthAudio requires voice when gradium is used');
+    assert.ok(credentials.api_key, 'synthAudio requires api_key when gradium is used');
+  } else if ('nineninesix' === vendor) {
+    assert.ok(voice, 'synthAudio requires voice when nineninesix is used');
+    assert.ok(credentials.api_key, 'synthAudio requires api_key when nineninesix is used');
+    assert.ok(credentials.model_id, 'synthAudio requires model_id when nineninesix is used');
+  } else if ('murf' === vendor) {
+    assert.ok(voice, 'synthAudio requires voice when murf is used');
+    assert.ok(credentials.api_key, 'synthAudio requires api_key when murf is used');
   } else if (vendor === 'resemble') {
     assert.ok(voice, 'synthAudio requires voice when resemble is used');
     assert.ok(credentials.api_key, 'synthAudio requires api_key when resemble is used');
@@ -201,6 +220,16 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
           credentials, options, stats, language, voice, key, text, renderForCaching, disableTtsStreaming,
           disableTtsCache});
         break;
+      case 'gradium':
+        audioData = await synthGradium(logger, {
+          credentials, options, stats, voice, key, text, renderForCaching, disableTtsStreaming,
+          disableTtsCache});
+        break;
+      case 'nineninesix':
+        audioData = await synthNineninesix(logger, {
+          credentials, stats, language, voice, key, text, renderForCaching, disableTtsStreaming,
+          disableTtsCache});
+        break;
       case 'inworld':
         audioData = await synthInworld(logger, {
           credentials, options, stats, language, voice, key, text, renderForCaching, disableTtsStreaming,
@@ -211,6 +240,11 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
           credentials, options, stats, language, voice, key, text, renderForCaching, disableTtsStreaming,
           disableTtsCache});
         break;
+      case 'murf':
+        audioData = await synthMurf(logger, {
+          credentials, options, stats, language, voice, key, text, renderForCaching, disableTtsStreaming,
+          disableTtsCache});
+        break;
       case 'whisper':
         audioData = await synthWhisper(logger, {
           credentials, stats, voice, key, text, instructions, renderForCaching, disableTtsStreaming,
@@ -220,6 +254,15 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
         audioData = await synthDeepgram(logger, {credentials, stats, model, key, text,
           renderForCaching, disableTtsStreaming, disableTtsCache});
         break;
+      case 'deepgramflux':
+        audioData = await synthDeepgramFlux(logger, {credentials, stats, model: model || voice, key, text,
+          renderForCaching, disableTtsStreaming, disableTtsCache});
+        break;
+      case 'xai':
+        audioData = await synthXai(logger, {
+          credentials, options, stats, language, voice, key, text, renderForCaching, disableTtsStreaming,
+          disableTtsCache});
+        break;
       case 'resemble':
         audioData = await synthResemble(logger, {
           credentials, stats, voice, key, text, options, renderForCaching, disableTtsStreaming, disableTtsCache});
@@ -358,6 +401,32 @@ const synthPolly = async(createHash, retrieveHash, logger,
   }
 };
 
+/* google AudioConfig settings we support, as [google camelCase name, freeswitch param name] */
+const GOOGLE_AUDIO_SETTINGS = [
+  ['speakingRate', 'speaking_rate'],
+  ['pitch', 'pitch'],
+  ['volumeGainDb', 'volume_gain_db']
+];
+
+/**
+ * Extract google AudioConfig settings from the synthesizer options.  They may be supplied
+ * nested under an audioConfig property (mirroring google's AudioConfig object) or flat at
+ * the top level, and either google's camelCase or snake_case names are accepted.
+ * @see https://cloud.google.com/text-to-speech/docs/reference/rest/v1/text/synthesize#AudioConfig
+ * @returns object keyed by google's camelCase names, holding only valid numeric settings
+ */
+const googleAudioConfig = (options) => {
+  const provided = {...options, ...(options?.audioConfig || {})};
+  const audioConfig = {};
+  for (const [name, snakeName] of GOOGLE_AUDIO_SETTINGS) {
+    const value = provided[name] ?? provided[snakeName];
+    /* note: 0 is meaningful for pitch and volumeGainDb, so check for absence explicitly */
+    if (value === undefined || value === null || value === '') continue;
+    const num = Number(value);
+    if (Number.isFinite(num)) audioConfig[name] = num;
+  }
+  return audioConfig;
+};
 
 const synthGoogle = async(logger, {
   credentials, stats, language, voice, gender, key, text, model, options, instructions,
@@ -393,6 +462,15 @@ const synthGoogle = async(logger, {
     // comma is used to separate parameters in freeswitch tts module
     const prompt = options?.prompt || instructions;
     if (prompt) params += `,prompt=${prompt.replace(/\n/g, ' ').replace(/,/g, ';')}`;
+    /**
+     * AudioConfig settings.  Note google only honors these in some api modes:
+     * tts applies all of them, live (HD voices) applies speakingRate only,
+     * and gemini ignores them entirely (use prompt instead for style control).
+     */
+    const audioSettings = googleAudioConfig(options);
+    for (const [name, snakeName] of GOOGLE_AUDIO_SETTINGS) {
+      if (name in audioSettings) params += `,${snakeName}=${audioSettings[name]}`;
+    }
     params += '}';
 
     return {
@@ -461,6 +539,9 @@ const synthGoogle = async(logger, {
     sampleRate = 8000;
   }
 
+  /* gemini voices do not support the AudioConfig settings; they use prompt for style control */
+  if (!isGemini) Object.assign(audioConfig, googleAudioConfig(options));
+
   const opts = { input, voice: voiceParams, audioConfig };
 
   try {
@@ -969,6 +1050,72 @@ const synthRimelabs = async(logger, {
     throw err;
   }
 };
+
+const synthMurf = async(logger, {
+  credentials, options, stats, language, voice, key, text, renderForCaching, disableTtsStreaming, disableTtsCache
+}) => {
+  const {api_key, model_id, api_uri, options: credOpts} = credentials;
+  const opts = !!options && Object.keys(options).length !== 0 ? options : JSON.parse(credOpts || '{}');
+
+  /* default to using the streaming interface, unless disabled by env var OR we want just a cache file */
+  if (!JAMBONES_DISABLE_TTS_STREAMING && !renderForCaching && !disableTtsStreaming) {
+    /* param keys here must match mod_murf_tts's text_param handler */
+    let params = '{';
+    params += `api_key=${api_key}`;
+    params += `,playback_id=${key}`;
+    params += ',vendor=murf';
+    params += `,voice=${voice}`;
+    if (model_id) params += `,model_id=${model_id}`;
+    if (language) params += `,language=${language}`;
+    if (api_uri) params += `,api_uri=${api_uri}`;
+    if (opts.style) params += `,style=${opts.style}`;
+    if (opts.rate !== undefined && opts.rate !== null) params += `,rate=${opts.rate}`;
+    if (opts.pitch !== undefined && opts.pitch !== null) params += `,pitch=${opts.pitch}`;
+    if (opts.variation !== undefined && opts.variation !== null) params += `,variation=${opts.variation}`;
+    params += `,write_cache_file=${disableTtsCache ? 0 : 1}`;
+    params += '}';
+
+    return {
+      filePath: `say:${params}${text.replace(/\n/g, ' ').replace(/\r/g, ' ')}`,
+      servedFromCache: false,
+      rtt: 0
+    };
+  }
+
+  try {
+    const sampleRate = 8000;
+    /* no Accept header: murf returns 406 if it doesn't match; the response
+       container is selected by the `format` field in the body instead */
+    const post = bent(api_uri || 'https://global.api.murf.ai', 'POST', 'buffer', {
+      'api-key': api_key,
+      'Content-Type': 'application/json'
+    });
+    /* murf REST schema is documented loosely; field names follow the SDK params
+       (voice_id/model/format/sample_rate) plus the websocket voice fields. */
+    const audioContent = await post('/v1/speech/stream', {
+      text,
+      voice_id: voice,
+      ...(model_id && {model: model_id}),
+      ...(language && {locale: language}),
+      ...(opts.style && {style: opts.style}),
+      ...(opts.rate !== undefined && opts.rate !== null && {rate: opts.rate}),
+      ...(opts.pitch !== undefined && opts.pitch !== null && {pitch: opts.pitch}),
+      ...(opts.variation !== undefined && opts.variation !== null && {variation: opts.variation}),
+      format: 'WAV',
+      sample_rate: sampleRate,
+      channel_type: 'MONO'
+    });
+    return {
+      audioContent,
+      extension: 'wav',
+      sampleRate
+    };
+  } catch (err) {
+    logger.info({err}, 'synth murf returned error');
+    stats.increment('tts.count', ['vendor:murf', 'accepted:no']);
+    throw err;
+  }
+};
 const synthWhisper = async(logger, {credentials, stats, voice, key, text, instructions,
   renderForCaching, disableTtsStreaming, disableTtsCache}) => {
   const {api_key, model_id, baseURL, timeout, speed} = credentials;
@@ -1059,6 +1206,116 @@ const synthDeepgram = async(logger, {credentials, stats, model, key, text, rende
   }
 };
 
+// Deepgram Flux TTS — the conversation-native model served from /v2/speak.
+// Streaming rides the mediajam deepgramflux dialect via a say: filePath; the
+// batch/cache path POSTs to /v2/speak (mp3 is batch-only for Flux).
+const synthDeepgramFlux = async(logger, {credentials, stats, model, key, text, renderForCaching,
+  disableTtsStreaming, disableTtsCache}) => {
+  const {api_key, deepgram_tts_uri} = credentials;
+  if (!JAMBONES_DISABLE_TTS_STREAMING && !renderForCaching && !disableTtsStreaming) {
+    let params = '{';
+    params += `api_key=${api_key}`;
+    params += `,playback_id=${key}`;
+    params += ',vendor=deepgramflux';
+    params += `,voice=${model}`;
+    params += `,write_cache_file=${disableTtsCache ? 0 : 1}`;
+    if (deepgram_tts_uri) params += `,endpoint=${deepgram_tts_uri}`;
+    params += '}';
+
+    return {
+      filePath: `say:${params}${text.replace(/\n/g, ' ')}`,
+      servedFromCache: false,
+      rtt: 0
+    };
+  }
+  try {
+    const post = bent(deepgram_tts_uri || 'https://api.deepgram.com', 'POST', 'buffer', {
+      // on-premise deepgram does not require to have api_key
+      ...(api_key && {'Authorization': `Token ${api_key}`}),
+      'Accept': 'audio/mpeg',
+      'Content-Type': 'application/json'
+    });
+    const audioContent = await post(`/v2/speak?model=${model}`, {
+      text
+    });
+    return {
+      audioContent,
+      extension: 'mp3',
+      sampleRate: 8000
+    };
+  } catch (err) {
+    logger.info({err}, 'synth Deepgram Flux returned error');
+    stats.increment('tts.count', ['vendor:deepgramflux', 'accepted:no']);
+    throw err;
+  }
+};
+
+const synthXai = async(logger, {
+  credentials, options, stats, language, voice, key, text, renderForCaching, disableTtsStreaming, disableTtsCache
+}) => {
+  const {api_key, api_uri, options: credOpts} = credentials;
+  const opts = !!options && Object.keys(options).length !== 0 ? options : JSON.parse(credOpts || '{}');
+  const speed = opts.speed;
+  if (!JAMBONES_DISABLE_TTS_STREAMING && !renderForCaching && !disableTtsStreaming) {
+    let params = '{';
+    params += `api_key=${api_key}`;
+    params += `,playback_id=${key}`;
+    params += ',vendor=xai';
+    if (voice) params += `,voice=${voice}`;
+    if (language) params += `,language=${language}`;
+    if (speed !== null && speed !== undefined) params += `,speed=${speed}`;
+    if (opts.optimize_streaming_latency != null) {
+      params += `,optimize_streaming_latency=${opts.optimize_streaming_latency}`;
+    }
+    if (opts.text_normalization != null) params += `,text_normalization=${opts.text_normalization}`;
+    params += `,write_cache_file=${disableTtsCache ? 0 : 1}`;
+    if (api_uri) params += `,endpoint=${api_uri}`;
+    params += '}';
+
+    return {
+      filePath: `say:${params}${text.replace(/\n/g, ' ').replace(/\r/g, ' ')}`,
+      servedFromCache: false,
+      rtt: 0
+    };
+  }
+  try {
+    const post = bent(`https://${api_uri || 'api.x.ai'}`, 'POST', 'buffer', {
+      'Authorization': `Bearer ${api_key}`,
+      'Content-Type': 'application/json'
+    });
+    const audioContent = await post('/v1/tts', {
+      text,
+      language: language || 'auto',
+      ...(voice && {voice_id: voice}),
+      ...(speed !== null && speed !== undefined && {speed}),
+      ...(opts.optimize_streaming_latency != null && {optimize_streaming_latency: opts.optimize_streaming_latency}),
+      ...(opts.text_normalization != null && {text_normalization: opts.text_normalization}),
+      output_format: {
+        codec: 'wav',
+        sample_rate: 8000
+      }
+    });
+    return {
+      audioContent,
+      extension: 'wav',
+      sampleRate: 8000
+    };
+  } catch (err) {
+    // xAI errors are JSON {code, error} - read the body so the surfaced message isn't 'undefined'
+    if (err.name === 'StatusError' && typeof err.text === 'function') {
+      try {
+        const body = await err.text();
+        if (body) err.message = body;
+      } catch (readErr) {
+        logger.info({readErr}, 'synth xai: failed to read error response body');
+      }
+    }
+    logger.info({err}, 'synth xai returned error');
+    stats.increment('tts.count', ['vendor:xai', 'accepted:no']);
+    throw err;
+  }
+};
+
 const synthCartesia = async(logger, {
   credentials, options, stats, voice, language, key, text, renderForCaching, disableTtsStreaming, disableTtsCache
 }) => {
@@ -1184,6 +1441,118 @@ const synthCartesia = async(logger, {
 
 };
 
+/* gradium.ai — json websocket for streaming, and a POST endpoint for the cache
+   render. only_audio:true + pcm_8000 returns bare little-endian 16-bit samples,
+   which is exactly the r8 container, so we avoid gradium's streaming wav header
+   (it carries 0xffffffff as the RIFF size, since length is unknown up front).
+*/
+const synthGradium = async(logger, {
+  credentials, options, stats, voice, key, text, renderForCaching, disableTtsStreaming, disableTtsCache
+}) => {
+  const {api_key, model_id} = credentials;
+  const {json_config, pronunciation_id} = options || {};
+
+  /* default to using the streaming interface, unless disabled by env var OR we want just a cache file */
+  if (!JAMBONES_DISABLE_TTS_STREAMING && !renderForCaching && !disableTtsStreaming) {
+    let params = '{';
+    params += `api_key=${api_key}`;
+    params += `,playback_id=${key}`;
+    params += ',vendor=gradium';
+    params += `,voice=${voice}`;
+    params += `,write_cache_file=${disableTtsCache ? 0 : 1}`;
+    if (model_id) params += `,model_id=${model_id}`;
+    if (pronunciation_id) params += `,pronunciation_id=${pronunciation_id}`;
+    params += '}';
+
+    return {
+      filePath: `say:${params}${text.replace(/\n/g, ' ').replace(/\r/g, ' ')}`,
+      servedFromCache: false,
+      rtt: 0
+    };
+  }
+
+  try {
+    const sampleRate = 8000;
+    const post = bent('https://api.gradium.ai', 'POST', 'buffer', {
+      'x-api-key': api_key,
+      'Content-Type': 'application/json'
+    });
+    const audioContent = await post('/api/post/speech/tts', {
+      text,
+      voice_id: voice,
+      model_name: model_id || 'default',
+      output_format: `pcm_${sampleRate}`,
+      only_audio: true,
+      ...(json_config && {json_config}),
+      ...(pronunciation_id && {pronunciation_id})
+    });
+    return {
+      audioContent,
+      extension: 'r8',
+      sampleRate
+    };
+  } catch (err) {
+    logger.info({err}, 'synth gradium returned error');
+    stats.increment('tts.count', ['vendor:gradium', 'accepted:no']);
+    throw err;
+  }
+};
+
+/* nineninesix.ai — a Cartesia-compatible API, but only raw/wav come back
+   (mp3 is rejected), so the cache render asks for wav rather than mp3. */
+const synthNineninesix = async(logger, {
+  credentials, stats, voice, language, key, text, renderForCaching, disableTtsStreaming, disableTtsCache
+}) => {
+  const {api_key, model_id} = credentials;
+
+  /* default to using the streaming interface, unless disabled by env var OR we want just a cache file */
+  if (!JAMBONES_DISABLE_TTS_STREAMING && !renderForCaching && !disableTtsStreaming) {
+    let params = '{';
+    params += `api_key=${api_key}`;
+    params += `,playback_id=${key}`;
+    params += `,model_id=${model_id}`;
+    params += ',vendor=nineninesix';
+    params += `,voice=${voice}`;
+    params += `,write_cache_file=${disableTtsCache ? 0 : 1}`;
+    if (language) params += `,language=${language}`;
+    params += '}';
+
+    return {
+      filePath: `say:${params}${text.replace(/\n/g, ' ').replace(/\r/g, ' ')}`,
+      servedFromCache: false,
+      rtt: 0
+    };
+  }
+
+  try {
+    const sampleRate = 8000;
+    const post = bent('https://api.nineninesix.ai', 'POST', 'buffer', {
+      'Authorization': `Bearer ${api_key}`,
+      'Content-Type': 'application/json'
+    });
+    const audioContent = await post('/tts/bytes', {
+      model_id,
+      transcript: text,
+      voice: {mode: 'id', id: voice},
+      ...(language && {language}),
+      output_format: {
+        container: 'wav',
+        encoding: 'pcm_s16le',
+        sample_rate: sampleRate
+      }
+    });
+    return {
+      audioContent,
+      extension: 'wav',
+      sampleRate
+    };
+  } catch (err) {
+    logger.info({err}, 'synth nineninesix returned error');
+    stats.increment('tts.count', ['vendor:nineninesix', 'accepted:no']);
+    throw err;
+  }
+};
+
 const synthResemble = async(logger, {
   credentials, options, stats, voice, key, text, renderForCaching, disableTtsStreaming, disableTtsCache
 }) => {

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@jambonz/speech-utils",
-  "version": "1.0.6",
+  "version": "1.0.13",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@jambonz/speech-utils",
-      "version": "1.0.6",
+      "version": "1.0.13",
       "license": "MIT",
       "dependencies": {
         "23": "^0.0.0",
@@ -19,7 +19,7 @@
         "bent": "^7.3.12",
         "debug": "^4.3.4",
         "google-protobuf": "^3.21.2",
-        "microsoft-cognitiveservices-speech-sdk": "1.38.0",
+        "microsoft-cognitiveservices-speech-sdk": "^1.51.0",
         "openai": "^4.98.0",
         "undici": "^7.5.0"
       },
@@ -760,6 +760,46 @@
         "node": ">=18.0.0"
       }
     },
+    "node_modules/@azure/abort-controller": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/@azure/abort-controller/-/abort-controller-2.2.0.tgz",
+      "integrity": "sha512-fNAjWnA/nZ2jz31kxR/AqRaUT8ewHBw/WuBIosK0moMy1C9e5ValbDfFdIxJzVOOYaYkV/b2F1S4H/aHiqfVQg==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.6.2"
+      },
+      "engines": {
+        "node": ">=22.0.0"
+      }
+    },
+    "node_modules/@azure/core-auth": {
+      "version": "1.11.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-auth/-/core-auth-1.11.0.tgz",
+      "integrity": "sha512-IUZydyTUkDnYdstOW9pFOOUQlBjAepK5teihDE3x6yxsPJs/hsAaaYpeGxdxrgtOiJbBKSjKW7MDk7AEhb4LRg==",
+      "license": "MIT",
+      "dependencies": {
+        "@azure/abort-controller": "^2.1.2",
+        "@azure/core-util": "^1.13.0",
+        "tslib": "^2.6.2"
+      },
+      "engines": {
+        "node": ">=22.0.0"
+      }
+    },
+    "node_modules/@azure/core-util": {
+      "version": "1.14.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-util/-/core-util-1.14.0.tgz",
+      "integrity": "sha512-9n2pWK61veAuN0V20t9lOuoV4CFMdyAZ1ygZzvBGk/pBBJRib/PjL9PLXa/aI2CcPpyHfqVsxxqLCYl6uZlfDw==",
+      "license": "MIT",
+      "dependencies": {
+        "@azure/abort-controller": "^2.1.2",
+        "@typespec/ts-http-runtime": "^0.3.0",
+        "tslib": "^2.6.2"
+      },
+      "engines": {
+        "node": ">=22.0.0"
+      }
+    },
     "node_modules/@babel/code-frame": {
       "version": "7.26.2",
       "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.26.2.tgz",
@@ -2391,6 +2431,20 @@
       "resolved": "https://registry.npmjs.org/@types/webrtc/-/webrtc-0.0.37.tgz",
       "integrity": "sha512-JGAJC/ZZDhcrrmepU4sPLQLIOIAgs5oIK+Ieq90K8fdaNMhfdfqmYatJdgif1NDQtvrSlTOGJDUYHIDunuufOg=="
     },
+    "node_modules/@typespec/ts-http-runtime": {
+      "version": "0.3.8",
+      "resolved": "https://registry.npmjs.org/@typespec/ts-http-runtime/-/ts-http-runtime-0.3.8.tgz",
+      "integrity": "sha512-bLMpVcWZNzq6lYOybwFwOAR1IXKcHnhUNqYeHjl1bET/qE3jFPFH+p8Wrh3rU4xwdnifPxmKNESBYnvnmc75aA==",
+      "license": "MIT",
+      "dependencies": {
+        "http-proxy-agent": "^7.0.0",
+        "https-proxy-agent": "^7.0.0",
+        "tslib": "^2.6.2"
+      },
+      "engines": {
+        "node": ">=22.0.0"
+      }
+    },
     "node_modules/23": {
       "version": "0.0.0",
       "resolved": "https://registry.npmjs.org/23/-/23-0.0.0.tgz",
@@ -5278,17 +5332,18 @@
       }
     },
     "node_modules/microsoft-cognitiveservices-speech-sdk": {
-      "version": "1.38.0",
-      "resolved": "https://registry.npmjs.org/microsoft-cognitiveservices-speech-sdk/-/microsoft-cognitiveservices-speech-sdk-1.38.0.tgz",
-      "integrity": "sha512-NA6J4eIDkeR9iN83rcn77Kn5AWQcizDEn1tLMjzRvSovUNB1FrZe0mWYO0fsGltUwMl3Ns5OZ3lGw42PU4fEYA==",
+      "version": "1.51.0",
+      "resolved": "https://registry.npmjs.org/microsoft-cognitiveservices-speech-sdk/-/microsoft-cognitiveservices-speech-sdk-1.51.0.tgz",
+      "integrity": "sha512-BLLovv5PegOr5Lp52h4CSgL2c/ViFAh9LoU49ILNPyb/Z0giGI7nPV3xNLcmTtHLT+kfYNRGUIA62vORLzP8TA==",
       "license": "MIT",
       "dependencies": {
+        "@azure/core-auth": "^1.9.0",
         "@types/webrtc": "^0.0.37",
         "agent-base": "^6.0.1",
         "bent": "^7.3.12",
         "https-proxy-agent": "^4.0.0",
-        "uuid": "^9.0.0",
-        "ws": "^7.5.6"
+        "uuid": "^11.1.1",
+        "ws": "^8.21.0"
       }
     },
     "node_modules/microsoft-cognitiveservices-speech-sdk/node_modules/https-proxy-agent": {
@@ -5312,36 +5367,16 @@
       }
     },
     "node_modules/microsoft-cognitiveservices-speech-sdk/node_modules/uuid": {
-      "version": "9.0.1",
-      "resolved": "https://registry.npmjs.org/uuid/-/uuid-9.0.1.tgz",
-      "integrity": "sha512-b+1eJOlsR9K8HJpow9Ok3fiWOWSIcIzXodvv0rQjVoOVNpWMpxf1wZNpt4y9h10odCNrqnYp1OBzRktckBe3sA==",
+      "version": "11.1.1",
+      "resolved": "https://registry.npmjs.org/uuid/-/uuid-11.1.1.tgz",
+      "integrity": "sha512-vIYxrBCC/N/K+Js3qSN88go7kIfNPssr/hHCesKCQNAjmgvYS2oqr69kIufEG+O4+PfezOH4EbIeHCfFov8ZgQ==",
       "funding": [
         "https://github.com/sponsors/broofa",
         "https://github.com/sponsors/ctavan"
       ],
-      "bin": {
-        "uuid": "dist/bin/uuid"
-      }
-    },
-    "node_modules/microsoft-cognitiveservices-speech-sdk/node_modules/ws": {
-      "version": "7.5.10",
-      "resolved": "https://registry.npmjs.org/ws/-/ws-7.5.10.tgz",
-      "integrity": "sha512-+dbF1tHwZpXcbOJdVOkzLDxZP1ailvSxM6ZweXTegylPny803bFhA+vqBYw4s31NSAk4S2Qz+AKXK9a4wkdjcQ==",
       "license": "MIT",
-      "engines": {
-        "node": ">=8.3.0"
-      },
-      "peerDependencies": {
-        "bufferutil": "^4.0.1",
-        "utf-8-validate": "^5.0.2"
-      },
-      "peerDependenciesMeta": {
-        "bufferutil": {
-          "optional": true
-        },
-        "utf-8-validate": {
-          "optional": true
-        }
+      "bin": {
+        "uuid": "dist/esm/bin/uuid"
       }
     },
     "node_modules/mime-db": {
@@ -7924,6 +7959,34 @@
       "resolved": "https://registry.npmjs.org/@aws/lambda-invoke-store/-/lambda-invoke-store-0.2.4.tgz",
       "integrity": "sha512-iY8yvjE0y651BixKNPgmv1WrQc+GZ142sb0z4gYnChDDY2YqI4P/jsSopBWrKfAt7LOJAkOXt7rC/hms+WclQQ=="
     },
+    "@azure/abort-controller": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/@azure/abort-controller/-/abort-controller-2.2.0.tgz",
+      "integrity": "sha512-fNAjWnA/nZ2jz31kxR/AqRaUT8ewHBw/WuBIosK0moMy1C9e5ValbDfFdIxJzVOOYaYkV/b2F1S4H/aHiqfVQg==",
+      "requires": {
+        "tslib": "^2.6.2"
+      }
+    },
+    "@azure/core-auth": {
+      "version": "1.11.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-auth/-/core-auth-1.11.0.tgz",
+      "integrity": "sha512-IUZydyTUkDnYdstOW9pFOOUQlBjAepK5teihDE3x6yxsPJs/hsAaaYpeGxdxrgtOiJbBKSjKW7MDk7AEhb4LRg==",
+      "requires": {
+        "@azure/abort-controller": "^2.1.2",
+        "@azure/core-util": "^1.13.0",
+        "tslib": "^2.6.2"
+      }
+    },
+    "@azure/core-util": {
+      "version": "1.14.0",
+      "resolved": "https://registry.npmjs.org/@azure/core-util/-/core-util-1.14.0.tgz",
+      "integrity": "sha512-9n2pWK61veAuN0V20t9lOuoV4CFMdyAZ1ygZzvBGk/pBBJRib/PjL9PLXa/aI2CcPpyHfqVsxxqLCYl6uZlfDw==",
+      "requires": {
+        "@azure/abort-controller": "^2.1.2",
+        "@typespec/ts-http-runtime": "^0.3.0",
+        "tslib": "^2.6.2"
+      }
+    },
     "@babel/code-frame": {
       "version": "7.26.2",
       "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.26.2.tgz",
@@ -9118,6 +9181,16 @@
       "resolved": "https://registry.npmjs.org/@types/webrtc/-/webrtc-0.0.37.tgz",
       "integrity": "sha512-JGAJC/ZZDhcrrmepU4sPLQLIOIAgs5oIK+Ieq90K8fdaNMhfdfqmYatJdgif1NDQtvrSlTOGJDUYHIDunuufOg=="
     },
+    "@typespec/ts-http-runtime": {
+      "version": "0.3.8",
+      "resolved": "https://registry.npmjs.org/@typespec/ts-http-runtime/-/ts-http-runtime-0.3.8.tgz",
+      "integrity": "sha512-bLMpVcWZNzq6lYOybwFwOAR1IXKcHnhUNqYeHjl1bET/qE3jFPFH+p8Wrh3rU4xwdnifPxmKNESBYnvnmc75aA==",
+      "requires": {
+        "http-proxy-agent": "^7.0.0",
+        "https-proxy-agent": "^7.0.0",
+        "tslib": "^2.6.2"
+      }
+    },
     "abort-controller": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/abort-controller/-/abort-controller-3.0.0.tgz",
@@ -11106,16 +11179,17 @@
       "integrity": "sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g=="
     },
     "microsoft-cognitiveservices-speech-sdk": {
-      "version": "1.38.0",
-      "resolved": "https://registry.npmjs.org/microsoft-cognitiveservices-speech-sdk/-/microsoft-cognitiveservices-speech-sdk-1.38.0.tgz",
-      "integrity": "sha512-NA6J4eIDkeR9iN83rcn77Kn5AWQcizDEn1tLMjzRvSovUNB1FrZe0mWYO0fsGltUwMl3Ns5OZ3lGw42PU4fEYA==",
+      "version": "1.51.0",
+      "resolved": "https://registry.npmjs.org/microsoft-cognitiveservices-speech-sdk/-/microsoft-cognitiveservices-speech-sdk-1.51.0.tgz",
+      "integrity": "sha512-BLLovv5PegOr5Lp52h4CSgL2c/ViFAh9LoU49ILNPyb/Z0giGI7nPV3xNLcmTtHLT+kfYNRGUIA62vORLzP8TA==",
       "requires": {
+        "@azure/core-auth": "^1.9.0",
         "@types/webrtc": "^0.0.37",
         "agent-base": "^6.0.1",
         "bent": "^7.3.12",
         "https-proxy-agent": "^4.0.0",
-        "uuid": "^9.0.0",
-        "ws": "^7.5.6"
+        "uuid": "^11.1.1",
+        "ws": "^8.21.0"
       },
       "dependencies": {
         "https-proxy-agent": {
@@ -11135,15 +11209,9 @@
           }
         },
         "uuid": {
-          "version": "9.0.1",
-          "resolved": "https://registry.npmjs.org/uuid/-/uuid-9.0.1.tgz",
-          "integrity": "sha512-b+1eJOlsR9K8HJpow9Ok3fiWOWSIcIzXodvv0rQjVoOVNpWMpxf1wZNpt4y9h10odCNrqnYp1OBzRktckBe3sA=="
-        },
-        "ws": {
-          "version": "7.5.10",
-          "resolved": "https://registry.npmjs.org/ws/-/ws-7.5.10.tgz",
-          "integrity": "sha512-+dbF1tHwZpXcbOJdVOkzLDxZP1ailvSxM6ZweXTegylPny803bFhA+vqBYw4s31NSAk4S2Qz+AKXK9a4wkdjcQ==",
-          "requires": {}
+          "version": "11.1.1",
+          "resolved": "https://registry.npmjs.org/uuid/-/uuid-11.1.1.tgz",
+          "integrity": "sha512-vIYxrBCC/N/K+Js3qSN88go7kIfNPssr/hHCesKCQNAjmgvYS2oqr69kIufEG+O4+PfezOH4EbIeHCfFov8ZgQ=="
         }
       }
     },

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@jambonz/speech-utils",
-  "version": "1.0.6",
+  "version": "1.0.13",
   "description": "TTS-related speech utilities for jambonz",
   "main": "index.js",
   "author": "Dave Horton",
@@ -35,7 +35,7 @@
     "bent": "^7.3.12",
     "debug": "^4.3.4",
     "google-protobuf": "^3.21.2",
-    "microsoft-cognitiveservices-speech-sdk": "1.38.0",
+    "microsoft-cognitiveservices-speech-sdk": "^1.51.0",
     "openai": "^4.98.0",
     "undici": "^7.5.0"
   },

test/synth.js

@@ -442,6 +442,95 @@ test('Google TTS streaming tests (!JAMBONES_DISABLE_TTS_STREAMING)', async(t) =>
     });
     t.ok(result.filePath.includes('api_mode=tts'), 'options.apiMode=tts overrides HD voice default');
 
+    /* AudioConfig settings (speakingRate, pitch, volumeGainDb) */
+    const googleCreds = {
+      credentials: {
+        client_email: creds.client_email,
+        private_key: creds.private_key,
+      },
+    };
+
+    // Test 9: AudioConfig nested under options.audioConfig, as in google's API docs
+    result = await synthAudio(stats, {
+      vendor: 'google',
+      credentials: googleCreds,
+      language: 'en-US',
+      voice: 'en-US-Wavenet-D',
+      text: 'Testing nested audioConfig settings.',
+      options: { audioConfig: { speakingRate: 1.4, pitch: -2.5, volumeGainDb: 6 } },
+      disableTtsCache: true
+    });
+    t.ok(result.filePath.includes(',speaking_rate=1.4'), 'nested audioConfig sets speaking_rate');
+    t.ok(result.filePath.includes(',pitch=-2.5'), 'nested audioConfig sets pitch');
+    t.ok(result.filePath.includes(',volume_gain_db=6'), 'nested audioConfig sets volume_gain_db');
+
+    // Test 10: AudioConfig flat at the top level of options, in camelCase or snake_case
+    result = await synthAudio(stats, {
+      vendor: 'google',
+      credentials: googleCreds,
+      language: 'en-US',
+      voice: 'en-US-Wavenet-D',
+      text: 'Testing flat audioConfig settings.',
+      options: { speaking_rate: '0.8', volumeGainDb: 3 },
+      disableTtsCache: true
+    });
+    t.ok(result.filePath.includes(',speaking_rate=0.8'), 'flat snake_case speaking_rate is honored');
+    t.ok(result.filePath.includes(',volume_gain_db=3'), 'flat camelCase volumeGainDb is honored');
+    t.ok(!result.filePath.includes(',pitch='), 'unspecified audioConfig setting is omitted');
+
+    // Test 11: zero is a meaningful value for pitch and volumeGainDb, not an absent one
+    result = await synthAudio(stats, {
+      vendor: 'google',
+      credentials: googleCreds,
+      language: 'en-US',
+      voice: 'en-US-Wavenet-D',
+      text: 'Testing zero audioConfig settings.',
+      options: { audioConfig: { pitch: 0, volumeGainDb: 0 } },
+      disableTtsCache: true
+    });
+    t.ok(result.filePath.includes(',pitch=0'), 'pitch=0 is passed through rather than dropped');
+    t.ok(result.filePath.includes(',volume_gain_db=0'), 'volume_gain_db=0 is passed through rather than dropped');
+
+    // Test 12: non-numeric values are ignored, so they cannot corrupt the freeswitch param string
+    result = await synthAudio(stats, {
+      vendor: 'google',
+      credentials: googleCreds,
+      language: 'en-US',
+      voice: 'en-US-Wavenet-D',
+      text: 'Testing invalid audioConfig settings.',
+      options: { audioConfig: { speakingRate: 'fast,evil=1', pitch: null, volumeGainDb: '' } },
+      disableTtsCache: true
+    });
+    t.ok(!result.filePath.includes('speaking_rate'), 'non-numeric speakingRate is ignored');
+    t.ok(!result.filePath.includes('evil=1'), 'non-numeric value cannot inject extra params');
+    t.ok(!result.filePath.includes('pitch='), 'null pitch is ignored');
+    t.ok(!result.filePath.includes('volume_gain_db'), 'empty volumeGainDb is ignored');
+
+    // Test 13: no audioConfig supplied leaves the param string untouched
+    result = await synthAudio(stats, {
+      vendor: 'google',
+      credentials: googleCreds,
+      language: 'en-US',
+      voice: 'en-US-Wavenet-D',
+      text: 'Testing absent audioConfig settings.',
+      disableTtsCache: true
+    });
+    t.ok(!/speaking_rate|pitch=|volume_gain_db/.test(result.filePath),
+      'no audioConfig params are added when none are supplied');
+
+    // Test 14: HD voice (api_mode=live) also carries speaking_rate, the one setting google streams support
+    result = await synthAudio(stats, {
+      vendor: 'google',
+      credentials: googleCreds,
+      language: 'en-US',
+      voice: 'en-US-Chirp3-HD-Charon',
+      text: 'Testing audioConfig on an HD voice.',
+      options: { audioConfig: { speakingRate: 1.25 } },
+      disableTtsCache: true
+    });
+    t.ok(result.filePath.includes('api_mode=live'), 'HD voice with audioConfig still uses api_mode=live');
+    t.ok(result.filePath.includes(',speaking_rate=1.25'), 'HD voice streaming path carries speaking_rate');
+
   } catch (err) {
     console.error(err);
     t.end(err);
@@ -526,6 +615,42 @@ test('Google TTS non-streaming tests (JAMBONES_DISABLE_TTS_STREAMING=true)', asy
     t.ok(!result.filePath.startsWith('say:'), 'Gemini TTS does NOT return streaming say: path when disabled');
     t.ok(result.filePath.endsWith('.mp3'), 'Gemini TTS returns mp3 file path');
 
+    const googleCreds = {
+      credentials: {
+        client_email: creds.client_email,
+        private_key: creds.private_key,
+      },
+    };
+
+    /**
+     * Test 4: AudioConfig settings are accepted by the synthesize API.
+     * Google rejects out-of-range values with a 400, so a successful render also confirms
+     * the settings reached the request rather than being silently dropped.
+     */
+    result = await synthAudio(stats, {
+      vendor: 'google',
+      credentials: googleCreds,
+      language: 'en-US',
+      voice: 'en-US-Wavenet-D',
+      text: 'This is a test of audioConfig with streaming disabled.',
+      options: { audioConfig: { speakingRate: 1.4, pitch: -2.5, volumeGainDb: 6 } },
+      disableTtsCache: true
+    });
+    t.ok(result.filePath.endsWith('.mp3'), 'standard voice renders mp3 with audioConfig settings applied');
+
+    /* Test 5: gemini voices ignore the AudioConfig settings rather than failing on them */
+    result = await synthAudio(stats, {
+      vendor: 'google',
+      credentials: googleCreds,
+      language: 'en-US',
+      voice: 'Kore',
+      model: geminiModel,
+      text: 'This is a test of audioConfig on Gemini TTS.',
+      options: { audioConfig: { speakingRate: 1.4, pitch: -2.5, volumeGainDb: 6 } },
+      disableTtsCache: true
+    });
+    t.ok(result.filePath.endsWith('.mp3'), 'gemini voice renders mp3 with audioConfig settings skipped');
+
   } catch (err) {
     console.error(err);
     t.end(err);
@@ -933,6 +1058,65 @@ test('Cartesia speech synth tests', async(t) => {
   client.quit();
 });
 
+test('gradium speech synth tests', async(t) => {
+  const fn = require('..');
+  const {synthAudio, client} = fn(opts, logger);
+
+  if (!process.env.GRADIUM_API_KEY) {
+    t.pass('skipping gradium speech synth tests since GRADIUM_API_KEY is not provided');
+    return t.end();
+  }
+  const text = 'Hi there and welcome to jambones! ' + Date.now();
+  try {
+    const opts = await synthAudio(stats, {
+      vendor: 'gradium',
+      credentials: {
+        api_key: process.env.GRADIUM_API_KEY,
+        model_id: 'default'
+      },
+      voice: 'YTpq7expH9539ERJ',
+      text,
+      renderForCaching: true
+    });
+    t.ok(!opts.servedFromCache, `successfully synthed gradium audio to ${opts.filePath}`);
+
+  } catch (err) {
+    console.error(JSON.stringify(err));
+    t.end(err);
+  }
+  client.quit();
+});
+
+test('nineninesix speech synth tests', async(t) => {
+  const fn = require('..');
+  const {synthAudio, client} = fn(opts, logger);
+
+  if (!process.env.NINENINESIX_API_KEY) {
+    t.pass('skipping nineninesix speech synth tests since NINENINESIX_API_KEY is not provided');
+    return t.end();
+  }
+  const text = 'Hi there and welcome to jambones! ' + Date.now();
+  try {
+    const opts = await synthAudio(stats, {
+      vendor: 'nineninesix',
+      credentials: {
+        api_key: process.env.NINENINESIX_API_KEY,
+        model_id: 'gepard-1.0'
+      },
+      language: 'en',
+      voice: '3ad7a827-7fd1-4954-bf35-47d4cc33d9ed',
+      text,
+      renderForCaching: true
+    });
+    t.ok(!opts.servedFromCache, `successfully synthed nineninesix audio to ${opts.filePath}`);
+
+  } catch (err) {
+    console.error(JSON.stringify(err));
+    t.end(err);
+  }
+  client.quit();
+});
+
 test('inworld speech synth', async(t) => {
   const fn = require('..');
   const {synthAudio, client} = fn(opts, logger);
@@ -1118,6 +1302,69 @@ test('Deepgram speech synth tests', async(t) => {
   client.quit();
 })
 
+test('Deepgram Flux speech synth tests', async(t) => {
+  const fn = require('..');
+  const {synthAudio, client} = fn(opts, logger);
+
+  if (!process.env.DEEPGRAM_API_KEY) {
+    t.pass('skipping Deepgram Flux speech synth tests since DEEPGRAM_API_KEY');
+    return t.end();
+  }
+  const text = 'Hi there and welcome to jambones!';
+  try {
+    const opts = await synthAudio(stats, {
+      vendor: 'deepgramflux',
+      credentials: {
+        api_key: process.env.DEEPGRAM_API_KEY
+      },
+      model: process.env.DEEPGRAM_FLUX_MODEL || 'flux-alexis-en',
+      text,
+      renderForCaching: true
+    });
+    t.ok(!opts.servedFromCache, `successfully synthesized deepgramflux audio to ${opts.filePath}`);
+
+  } catch (err) {
+    console.error(JSON.stringify(err));
+    t.end(err);
+  }
+  client.quit();
+});
+
+test('xai speech synth tests', async(t) => {
+  const fn = require('..');
+  const {synthAudio, client} = fn(opts, logger);
+
+  if (!process.env.XAI_API_KEY) {
+    t.pass('skipping xai speech synth tests - no XAI_API_KEY');
+    return t.end();
+  }
+  const text = 'Hi there and welcome to jambones!';
+  try {
+    const opts = await synthAudio(stats, {
+      vendor: 'xai',
+      credentials: {
+        api_key: process.env.XAI_API_KEY,
+        options: JSON.stringify({
+          voice: process.env.XAI_VOICE || 'eve',
+          speed: 1.0,
+          optimize_streaming_latency: 1,
+          text_normalization: true
+        })
+      },
+      language: 'en',
+      voice: process.env.XAI_VOICE || 'eve',
+      text,
+      renderForCaching: true
+    });
+    t.ok(!opts.servedFromCache && opts.filePath, `successfully synthesized xai audio to ${opts.filePath}`);
+
+  } catch (err) {
+    console.error(JSON.stringify(err));
+    t.end(err);
+  }
+  client.quit();
+});
+
 test('TTS Cache tests', async(t) => {
   const fn = require('..');
   const {purgeTtsCache, getTtsSize, client} = fn(opts, logger);