--- title: xAI Text-to-Speech | Runware Docs url: https://runware.ai/docs/models/xai-tts description: Expressive text-to-speech with five voices, speech tags, and multilingual support --- # xAI Text-to-Speech xAI Text-to-Speech converts text into natural-sounding spoken audio with a single API call. It offers five expressive voices (Eve, Ara, Leo, Rex, and Sal), inline speech tags for fine-grained control over pauses, laughter, whispers, and emphasis, and supports over 20 auto-detected languages. - **ID**: `xai:tts@0` - **Status**: live - **Creator**: xAI - **Release Date**: March 16, 2026 - **Capabilities**: Text to Audio ## Pricing $0.0042 per 1,000 characters - **1000 characters**: `$0.0042` ## Request Parameters **API Options** Platform-level options for task execution and delivery. ### [taskType](https://runware.ai/docs/models/xai-tts#request-tasktype) - **Type**: `string` - **Required**: true - **Value**: `audioInference` Identifier for the type of task being performed ### [taskUUID](https://runware.ai/docs/models/xai-tts#request-taskuuid) - **Type**: `string` - **Required**: true - **Format**: `UUID v4` UUID v4 identifier for tracking tasks and matching async responses. Must be unique per task. ### [outputType](https://runware.ai/docs/models/xai-tts#request-outputtype) - **Type**: `string` - **Default**: `URL` Audio output type. **Allowed values**: `URL` `base64Data` `dataURI` ### [outputFormat](https://runware.ai/docs/models/xai-tts#request-outputformat) - **Type**: `string` - **Default**: `MP3` Specifies the file format of the generated output. The available values depend on the task type and the specific model's capabilities. - \`MP3\`: Compressed audio, smaller file size. - \`WAV\`: Uncompressed, high-quality audio. - \`FLAC\`: Lossless compression. - \`OGG\`: Open-source compressed audio format (Vorbis codec). **Allowed values**: `MP3` `WAV` `FLAC` `OGG` ### [audioSettings](https://runware.ai/docs/models/xai-tts#request-audiosettings) - **Path**: `audioSettings.bitrate` - **Type**: `object (3 properties)` Audio encoding settings for controlling the bitrate, number of channels, and sample rate of the generated audio. Only applicable for lossy output formats (`MP3` and `OGG`). When using lossless formats (`WAV` or `FLAC`), this parameter must not be provided. The available sample rates and valid bitrate ranges depend on the output format. For `OGG`, bitrate limits also vary by the number of channels. **MP3 bitrate limits**: Bitrate limits for MP3 are the same regardless of mono or stereo. | Sample Rate | Min Bitrate | Max Bitrate | | --- | --- | --- | | 8,000 Hz | 8 kbps | 64 kbps | | 11,025 Hz | 8 kbps | 64 kbps | | 12,000 Hz | 8 kbps | 64 kbps | | 16,000 Hz | 8 kbps | 160 kbps | | 22,050 Hz | 8 kbps | 160 kbps | | 24,000 Hz | 8 kbps | 160 kbps | | 32,000 Hz | 32 kbps | 320 kbps | | 44,100 Hz | 32 kbps | 320 kbps | | 48,000 Hz | 32 kbps | 320 kbps | **OGG bitrate limits — Mono (1 channel)**: | Sample Rate | Min Bitrate | Max Bitrate | | --- | --- | --- | | 8,000 Hz | 8 kbps | 40 kbps | | 12,000 Hz | 16 kbps | 48 kbps | | 16,000 Hz | 16 kbps | 96 kbps | | 24,000 Hz | 16 kbps | 80 kbps | | 48,000 Hz | 32 kbps | 224 kbps | **OGG bitrate limits — Stereo (2 channels)**: | Sample Rate | Min Bitrate | Max Bitrate | | --- | --- | --- | | 8,000 Hz | 16 kbps | 80 kbps | | 12,000 Hz | 16 kbps | 96 kbps | | 16,000 Hz | 24 kbps | 192 kbps | | 24,000 Hz | 32 kbps | 160 kbps | | 48,000 Hz | 48 kbps | 256 kbps | > [!NOTE] > **Lossless formats**: When `outputFormat` is set to `WAV` or `FLAC`, the `audioSettings` parameter is not available since these formats produce uncompressed or lossless audio with no configurable encoding settings. #### [bitrate](https://runware.ai/docs/models/xai-tts#request-audiosettings-bitrate) - **Path**: `audioSettings.bitrate` - **Type**: `integer` - **Min**: `8` Audio bitrate in kbps. #### [channels](https://runware.ai/docs/models/xai-tts#request-audiosettings-channels) - **Path**: `audioSettings.channels` - **Type**: `integer` - **Default**: `2` Number of audio channels. 1 for mono, 2 for stereo. **Allowed values**: `1` `2` #### [sampleRate](https://runware.ai/docs/models/xai-tts#request-audiosettings-samplerate) - **Path**: `audioSettings.sampleRate` - **Type**: `integer` Audio sample rate in Hz. ### [webhookURL](https://runware.ai/docs/models/xai-tts#request-webhookurl) - **Type**: `string` - **Format**: `URI` Specifies a webhook URL where JSON responses will be sent via HTTP POST when generation tasks complete. For batch requests with multiple results, each completed item triggers a separate webhook call as it becomes available. **Learn more** (1 resource): - [Webhooks](https://runware.ai/docs/platform/webhooks) (platform) ### [deliveryMethod](https://runware.ai/docs/models/xai-tts#request-deliverymethod) - **Type**: `string` - **Default**: `sync` Determines how the API delivers task results. **Allowed values**: - `sync` Returns complete results directly in the API response. - `async` Returns an immediate acknowledgment with the task UUID. Poll for results using getResponse. **Learn more** (1 resource): - [Task Polling](https://runware.ai/docs/platform/task-polling) (platform) ### [uploadEndpoint](https://runware.ai/docs/models/xai-tts#request-uploadendpoint) - **Type**: `string` - **Format**: `URI` Specifies a URL where the generated content will be automatically uploaded using the HTTP PUT method. The raw binary data of the media file is sent directly as the request body. For secure uploads to cloud storage, use presigned URLs that include temporary authentication credentials. **Common use cases:** - **Cloud storage**: Upload directly to S3 buckets, Google Cloud Storage, or Azure Blob Storage using presigned URLs. - **CDN integration**: Upload to content delivery networks for immediate distribution. ```text // S3 presigned URL for secure upload https://your-bucket.s3.amazonaws.com/generated/content.mp4?X-Amz-Signature=abc123&X-Amz-Expires=3600 // Google Cloud Storage presigned URL https://storage.googleapis.com/your-bucket/content.jpg?X-Goog-Signature=xyz789 // Custom storage endpoint https://storage.example.com/uploads/generated-image.jpg ``` The content data will be sent as the request body to the specified URL when generation is complete. ### [ttl](https://runware.ai/docs/models/xai-tts#request-ttl) - **Type**: `integer` - **Min**: `60` Time-to-live (TTL) in seconds for generated content. Only applies when `outputType` is `URL`. ### [includeCost](https://runware.ai/docs/models/xai-tts#request-includecost) - **Type**: `boolean` - **Default**: `false` Include task cost in the response. ### [numberResults](https://runware.ai/docs/models/xai-tts#request-numberresults) - **Type**: `integer` - **Min**: `1` - **Max**: `4` - **Default**: `1` Number of results to generate. Each result uses a different seed, producing variations of the same parameters. **Generation Parameters** Core parameters for controlling the generated content. ### [model](https://runware.ai/docs/models/xai-tts#request-model) - **Type**: `string` - **Required**: true - **Value**: `xai:tts@0` Identifier of the model to use for generation. **Learn more** (3 resources): - [Text To Image: Model Selection The Foundation Of Generation](https://runware.ai/docs/guides/text-to-image#model-selection-the-foundation-of-generation) (guide) - [Image Inpainting: Model Specialized Inpainting Models](https://runware.ai/docs/guides/image-inpainting#model-specialized-inpainting-models) (guide) - [Image Outpainting: Other Critical Parameters](https://runware.ai/docs/guides/image-outpainting#other-critical-parameters) (guide) ### [speech](https://runware.ai/docs/models/xai-tts#request-speech) - **Path**: `speech.text` - **Type**: `object (3 properties)` - **Required**: true Settings for speech generation. #### [text](https://runware.ai/docs/models/xai-tts#request-speech-text) - **Path**: `speech.text` - **Type**: `string` - **Required**: true Text to convert to speech. #### [voice](https://runware.ai/docs/models/xai-tts#request-speech-voice) - **Path**: `speech.voice` - **Type**: `string` - **Required**: true - **Default**: `auto` Voice identifier to use. Set to `auto` for automatic selection. **Allowed values**: `una` `leo` `eve` `ara` `sal` `rex` #### [language](https://runware.ai/docs/models/xai-tts#request-speech-language) - **Path**: `speech.language` - **Type**: `string` - **Min**: `1` Language code for speech generation. **Allowed values**: `en` `ar-EG` `ar-SA` `ar-AE` `bn` `zh` `fr` `de` `hi` `id` `it` `ja` `ko` `pt-BR` `pt-PT` `ru` `es-MX` `es-ES` `tr` `vi` ## Response Parameters ### [taskType](https://runware.ai/docs/models/xai-tts#response-tasktype) - **Type**: `string` - **Required**: true - **Value**: `audioInference` Type of the task. ### [taskUUID](https://runware.ai/docs/models/xai-tts#response-taskuuid) - **Type**: `string` - **Required**: true - **Format**: `UUID v4` UUID of the task. ### [audioUUID](https://runware.ai/docs/models/xai-tts#response-audiouuid) - **Type**: `string` - **Required**: true - **Format**: `UUID v4` UUID of the output audio. ### [audioURL](https://runware.ai/docs/models/xai-tts#response-audiourl) - **Type**: `string` - **Format**: `URI` URL of the output audio. ### [audioBase64Data](https://runware.ai/docs/models/xai-tts#response-audiobase64data) - **Type**: `string` Base64-encoded audio data. ### [audioDataURI](https://runware.ai/docs/models/xai-tts#response-audiodatauri) - **Type**: `string` - **Format**: `URI` Data URI of the output audio. ### [seed](https://runware.ai/docs/models/xai-tts#response-seed) - **Type**: `integer` The seed used for generation. If none was provided, shows the randomly generated seed. ### [cost](https://runware.ai/docs/models/xai-tts#response-cost) - **Type**: `float` Task cost in USD. Present when `includeCost` is set to `true` in the request. ## Examples ### French Travel Narration (Text to Audio) [Listen to audio](https://assets.runware.ai/examples/xai-tts/469c523b-4053-48f1-b405-cf915a202ed8.mp3) **Request**: ```json { "taskType": "audioInference", "taskUUID": "583bb6a1-3d00-484f-a442-f1e61bf53dd7", "model": "xai:tts@0", "speech": { "text": "Bienvenue à Paris. Au lever du soleil, la Seine scintille comme un ruban d'or, les cafés s'éveillent lentement, et la ville murmure déjà ses histoires. Écoutez le tintement des tasses, le pas pressé des passants, et le souffle léger du vent autour de la tour Eiffel. Ce voyage commence ici, avec élégance, lumière, et un peu de magie.", "voice": "eve", "language": "fr" } } ``` **Response**: ```json { "taskType": "audioInference", "taskUUID": "583bb6a1-3d00-484f-a442-f1e61bf53dd7", "audioUUID": "43b5f1e3-5853-42f9-9b34-a74c502f0001", "audioURL": "https://am.runware.ai/audio/os/a18d05/ws/5/ai/43b5f1e3-5853-42f9-9b34-a74c502f0001.mp3", "cost": 0.00174 } ``` --- ### Expressive Story Narration (Text to Audio) [Listen to audio](https://assets.runware.ai/examples/xai-tts/2659ccb3-fc27-412a-979f-28b91aa6eb7b.mp3) **Request**: ```json { "taskType": "audioInference", "taskUUID": "e844d206-9c52-4597-bc4a-f83313956968", "model": "xai:tts@0", "speech": { "text": "The observatory lights dimmed one by one. [pause] Above the mountain, the sky opened like black velvet stitched with stars. \"Do you see it?\" she whispered. [whisper] \"The comet is early.\" [pause] Then, with a sudden laugh, she pointed east. [laugh] \"There! A silver flame across the dark.\" And for one breathless moment, the whole world stood still.", "voice": "eve", "language": "en" } } ``` **Response**: ```json { "taskType": "audioInference", "taskUUID": "e844d206-9c52-4597-bc4a-f83313956968", "audioUUID": "21467765-7783-4630-8c0d-e618dca19eb7", "audioURL": "https://am.runware.ai/audio/os/a01d21/ws/5/ai/21467765-7783-4630-8c0d-e618dca19eb7.mp3", "cost": 0.00147 } ``` --- ### Spanish Travel Narration (Text to Audio) [Listen to audio](https://assets.runware.ai/examples/xai-tts/4d5b9404-fc88-41c0-8ff7-81c28382d6b0.mp3) **Request**: ```json { "taskType": "audioInference", "taskUUID": "3cc30108-1696-446e-9d02-3c77a94183ef", "model": "xai:tts@0", "speech": { "text": "Bienvenidos a Sevilla, una ciudad de luz dorada, patios llenos de flores y música que vibra en cada rincón. Al caer la tarde, la Giralda se recorta contra el cielo, y las calles estrechas invitan a perderse sin prisa. [pause] Respira hondo. Escucha el murmullo de las plazas, el eco de los pasos sobre la piedra y la calidez de una noche que apenas comienza.", "voice": "eve", "language": "es-ES" } } ``` **Response**: ```json { "taskType": "audioInference", "taskUUID": "3cc30108-1696-446e-9d02-3c77a94183ef", "audioUUID": "2457d5b1-ee39-4d7a-af4d-aab1cee49ed6", "audioURL": "https://am.runware.ai/audio/os/a10d08/ws/5/ai/2457d5b1-ee39-4d7a-af4d-aab1cee49ed6.mp3", "cost": 0.0015 } ``` --- ### Hindi Guided Meditation (Text to Audio) [Listen to audio](https://assets.runware.ai/examples/xai-tts/ebac7977-3764-4fb5-a8b0-abf7b0971896.mp3) **Request**: ```json { "taskType": "audioInference", "taskUUID": "4a9f110c-7e7a-4f76-91f5-f5e9648d85af", "model": "xai:tts@0", "speech": { "text": "अपनी आँखें धीरे से बंद करें, और एक लंबी, गहरी साँस लें। महसूस करें कि हर साँस के साथ आपका मन शांत होता जा रहा है। आपके आसपास एक कोमल, सुनहरी रोशनी फैल रही है, जो आपको सुरक्षा, स्थिरता और सुकून का एहसास दे रही है। अब धीरे-धीरे साँस छोड़ें, और दिन भर का तनाव अपने शरीर से बाहर जाने दें।", "voice": "ara", "language": "hi" } } ``` **Response**: ```json { "taskType": "audioInference", "taskUUID": "4a9f110c-7e7a-4f76-91f5-f5e9648d85af", "audioUUID": "dcbcc15a-5273-4c3a-b87c-569f95adf918", "audioURL": "https://am.runware.ai/audio/os/a19d05/ws/5/ai/dcbcc15a-5273-4c3a-b87c-569f95adf918.mp3", "cost": 0.00145 } ```