> ## Documentation Index > Fetch the complete documentation index at: https://docs.slng.ai/llms.txt > Use this file to discover all available pages before exploring further. # Soniox TTS v1 > Stream real-time speech synthesis from Soniox TTS v1 over WebSocket with low-latency incremental audio output and SLNG's unified TTS protocol. **Hosting: routed through SLNG (Soniox).** This model runs on Soniox's servers; SLNG proxies each request through the nearest regional gateway. Available in Netherlands, Germany, United States (East, West), Australia, Brazil, United Kingdom, Indonesia, Israel, India, Japan, Singapore, South Africa. Connect to your region's gateway WebSocket endpoint: `wss://eu-north.api.slng.ai`, `wss://eu-west.api.slng.ai`, `wss://us-east.api.slng.ai`, `wss://us-west.api.slng.ai`, `wss://au.api.slng.ai`, `wss://br.api.slng.ai`, `wss://gb.api.slng.ai`, `wss://id.api.slng.ai`, `wss://il.api.slng.ai`, `wss://in.api.slng.ai`, `wss://jp.api.slng.ai`, `wss://sg.api.slng.ai`, `wss://za.api.slng.ai`. ## AsyncAPI ````yaml api-reference/asyncapi/tts-soniox.asyncapi.yaml /v1/tts/soniox/tts-rt:v1 id: /v1/tts/soniox/tts-rt:v1 title: Soniox TTS v1 description: >- Stream real-time speech synthesis from Soniox TTS v1 over WebSocket with low-latency incremental audio output and SLNG's unified TTS protocol. servers: - id: production-eu-north protocol: wss host: eu-north.api.slng.ai bindings: [] variables: [] - id: production-eu-west protocol: wss host: eu-west.api.slng.ai bindings: [] variables: [] - id: production-us-east protocol: wss host: us-east.api.slng.ai bindings: [] variables: [] - id: production-us-west protocol: wss host: us-west.api.slng.ai bindings: [] variables: [] - id: production-au protocol: wss host: au.api.slng.ai bindings: [] variables: [] - id: production-br protocol: wss host: br.api.slng.ai bindings: [] variables: [] - id: production-gb protocol: wss host: gb.api.slng.ai bindings: [] variables: [] - id: production-id protocol: wss host: id.api.slng.ai bindings: [] variables: [] - id: production-il protocol: wss host: il.api.slng.ai bindings: [] variables: [] - id: production-in protocol: wss host: in.api.slng.ai bindings: [] variables: [] - id: production-jp protocol: wss host: jp.api.slng.ai bindings: [] variables: [] - id: production-sg protocol: wss host: sg.api.slng.ai bindings: [] variables: [] - id: production-za protocol: wss host: za.api.slng.ai bindings: [] variables: [] address: /v1/tts/soniox/tts-rt:v1 parameters: [] bindings: - protocol: ws version: latest value: method: GET schemaProperties: - name: method type: string description: GET required: false operations: - &ref_1 id: ttsSonioxTtsRtV1ReceiveConfig title: Tts soniox tts rt v1 receive config description: Initialize a TTS stream type: receive messages: - &ref_7 id: SonioxTtsRtV1Config contentType: application/json payload: - name: Connection Config Message description: >- Initialize a TTS stream. Sent once per stream_id before any text frames. type: object properties: - name: type type: string description: >- Message type discriminator. Always `init` for the connection config message. required: true - name: api_key type: string description: >- Soniox API key or temporary API key. Created in Soniox Console. Optional on gateway routes — when provided it is ignored; upstream auth is injected by the gateway. required: false - name: stream_id type: string description: >- Client-generated unique stream identifier. Must be unique among active streams on the same connection. Can be reused only after the previous stream is terminated. required: true - name: model type: string description: TTS model to use. Example, `tts-rt-v1`. required: true - name: language type: string description: ISO 639-1 language code. Example, `en`. enumValues: - af - sq - ar - az - eu - be - bn - bs - bg - ca - zh - hr - cs - da - nl - en - et - fi - fr - gl - de - el - gu - he - hi - hu - id - it - ja - kn - kk - ko - lv - lt - mk - ms - ml - mr - 'no' - fa - pl - pt - pa - ro - ru - sr - sk - sl - es - sw - sv - tl - ta - te - th - tr - uk - ur - vi - cy required: true - name: voice type: string description: Voice name. Example, `Adrian`. required: true - name: audio_format type: string description: Output audio format. Example, `wav`. enumValues: - wav - mp3 - pcm_s16le - pcm_s16be required: true - name: sample_rate type: integer description: Output sample rate in Hz. Example, `24000`. required: false - name: bitrate type: integer description: >- Codec bitrate in bps. Only applicable to lossy compressed formats. Example, `128000`. required: false headers: [] jsonPayloadSchema: type: object description: >- Initialize a TTS stream. Sent once per stream_id before any text frames. required: - type - stream_id - model - language - voice - audio_format properties: type: type: string const: init description: >- Message type discriminator. Always `init` for the connection config message. x-parser-schema-id: api_key: type: string description: >- Soniox API key or temporary API key. Created in Soniox Console. Optional on gateway routes — when provided it is ignored; upstream auth is injected by the gateway. x-parser-schema-id: stream_id: type: string description: >- Client-generated unique stream identifier. Must be unique among active streams on the same connection. Can be reused only after the previous stream is terminated. x-parser-schema-id: model: type: string default: tts-rt-v1 description: TTS model to use. Example, `tts-rt-v1`. x-parser-schema-id: language: type: string default: en description: ISO 639-1 language code. Example, `en`. enum: - af - sq - ar - az - eu - be - bn - bs - bg - ca - zh - hr - cs - da - nl - en - et - fi - fr - gl - de - el - gu - he - hi - hu - id - it - ja - kn - kk - ko - lv - lt - mk - ms - ml - mr - 'no' - fa - pl - pt - pa - ro - ru - sr - sk - sl - es - sw - sv - tl - ta - te - th - tr - uk - ur - vi - cy x-parser-schema-id: voice: type: string description: Voice name. Example, `Adrian`. x-parser-schema-id: audio_format: type: string enum: - wav - mp3 - pcm_s16le - pcm_s16be description: Output audio format. Example, `wav`. x-parser-schema-id: sample_rate: type: integer description: Output sample rate in Hz. Example, `24000`. x-parser-schema-id: bitrate: type: integer description: >- Codec bitrate in bps. Only applicable to lossy compressed formats. Example, `128000`. x-parser-schema-id: x-parser-schema-id: title: Connection Config Message description: >- Initialize a TTS stream. Sent once per stream_id before any text frames. example: |- { "type": "init", "stream_id": "stream-1", "model": "tts-rt-v1", "language": "en", "voice": "Adrian", "audio_format": "wav", "sample_rate": 24000 } bindings: [] extensions: - id: x-parser-unique-object-id value: SonioxTtsRtV1Config bindings: [] extensions: &ref_0 - id: x-parser-unique-object-id value: /v1/tts/soniox/tts-rt:v1 - &ref_2 id: ttsSonioxTtsRtV1ReceiveTextStreaming title: Tts soniox tts rt v1 receive text streaming description: Stream text to synthesize type: receive messages: - &ref_8 id: SonioxTtsRtV1TextStreaming contentType: application/json payload: - name: Text Streaming Message description: >- Stream text incrementally to the active stream. Set text_end true on the final chunk. type: object properties: - name: type type: string description: >- Message type discriminator. Always `text` for streaming text chunks. required: true - name: stream_id type: string description: >- Must match the stream_id used in the connection config message. required: true - name: text type: string description: >- Text chunk to synthesize. Send incrementally as text is generated. required: true - name: text_end type: boolean description: >- Set to true on the final text chunk to signal end of input. False for intermediate chunks. required: true headers: [] jsonPayloadSchema: type: object description: >- Stream text incrementally to the active stream. Set text_end true on the final chunk. required: - type - stream_id - text - text_end properties: type: type: string const: text description: >- Message type discriminator. Always `text` for streaming text chunks. x-parser-schema-id: stream_id: type: string description: Must match the stream_id used in the connection config message. x-parser-schema-id: text: type: string description: >- Text chunk to synthesize. Send incrementally as text is generated. x-parser-schema-id: text_end: type: boolean description: >- Set to true on the final text chunk to signal end of input. False for intermediate chunks. x-parser-schema-id: x-parser-schema-id: title: Text Streaming Message description: >- Stream text incrementally to the active stream. Set text_end true on the final chunk. example: |- { "type": "text", "stream_id": "stream-1", "text": "Hello from Soniox text-to-speech.", "text_end": false } bindings: [] extensions: - id: x-parser-unique-object-id value: SonioxTtsRtV1TextStreaming bindings: [] extensions: *ref_0 - &ref_3 id: ttsSonioxTtsRtV1ReceiveCancel title: Tts soniox tts rt v1 receive cancel description: Cancel an in-flight stream type: receive messages: - &ref_9 id: SonioxTtsRtV1Cancel contentType: application/json payload: - name: Cancel Message description: >- Cancel an in-flight stream. Server stops audio and terminates the stream. type: object properties: - name: type type: string description: >- Message type discriminator. Always `clear` for the cancel message. required: true - name: stream_id type: string description: Stream to cancel. required: true - name: const type: boolean required: false - name: description type: string description: >- Must be `true` to trigger cancellation. Server will not send further audio and will terminate the stream. required: false headers: [] jsonPayloadSchema: type: object description: >- Cancel an in-flight stream. Server stops audio and terminates the stream. required: - type - stream_id - cancel properties: type: type: string const: clear description: >- Message type discriminator. Always `clear` for the cancel message. x-parser-schema-id: stream_id: type: string description: Stream to cancel. x-parser-schema-id: cancel: const: true description: >- Must be `true` to trigger cancellation. Server will not send further audio and will terminate the stream. x-parser-schema-id: x-parser-schema-id: title: Cancel Message description: >- Cancel an in-flight stream. Server stops audio and terminates the stream. example: |- { "type": "clear", "stream_id": "stream-1", "cancel": true } bindings: [] extensions: - id: x-parser-unique-object-id value: SonioxTtsRtV1Cancel bindings: [] extensions: *ref_0 - &ref_4 id: ttsSonioxTtsRtV1SendAudioChunk title: Tts soniox tts rt v1 send audio chunk description: Receive synthesized audio chunks type: send messages: - &ref_10 id: SonioxTtsRtV1AudioChunk contentType: application/json payload: - name: Audio Response description: >- Audio bytes for the stream chunk. audio_end true marks the final audio payload (stream not yet terminated). type: object properties: - name: type type: string description: >- Message type discriminator. Always `audio_chunk` for audio response messages. required: true - name: audio type: string description: Base64-encoded audio bytes for the stream chunk. required: true - name: audio_end type: boolean description: >- True on the final audio chunk. No further audio payloads will follow, but the stream is not fully closed until a Terminal Stream Event arrives with terminated: true. required: true - name: stream_id type: string description: Identifies which stream this audio belongs to. required: true headers: [] jsonPayloadSchema: type: object description: >- Audio bytes for the stream chunk. audio_end true marks the final audio payload (stream not yet terminated). required: - type - audio - audio_end - stream_id properties: type: type: string const: audio_chunk description: >- Message type discriminator. Always `audio_chunk` for audio response messages. x-parser-schema-id: audio: type: string format: base64 description: Base64-encoded audio bytes for the stream chunk. x-parser-schema-id: audio_end: type: boolean description: >- True on the final audio chunk. No further audio payloads will follow, but the stream is not fully closed until a Terminal Stream Event arrives with terminated: true. x-parser-schema-id: stream_id: type: string description: Identifies which stream this audio belongs to. x-parser-schema-id: x-parser-schema-id: title: Audio Response description: >- Audio bytes for the stream chunk. audio_end true marks the final audio payload (stream not yet terminated). example: |- { "type": "audio_chunk", "audio": "UklGRiQAAABXQVZFZm10IBAAAAABAAEAQB8AAEAfAAABAAgAZGF0YQAAAAA=", "audio_end": false, "stream_id": "stream-1" } bindings: [] extensions: - id: x-parser-unique-object-id value: SonioxTtsRtV1AudioChunk bindings: [] extensions: *ref_0 - &ref_5 id: ttsSonioxTtsRtV1SendTerminated title: Tts soniox tts rt v1 send terminated description: Receive stream termination event type: send messages: - &ref_11 id: SonioxTtsRtV1Terminated contentType: application/json payload: - name: Terminal Stream Event description: >- Server has fully closed the stream and released resources. stream_id may now be reused. type: object properties: - name: type type: string description: >- Message type discriminator. Always `terminated` for the terminal stream event. required: true - name: const type: boolean required: false - name: description type: string description: >- True signals the server has fully closed the stream and released resources. Safe to reuse stream_id only after this event. required: false - name: stream_id type: string description: Stream this termination event applies to. required: true headers: [] jsonPayloadSchema: type: object description: >- Server has fully closed the stream and released resources. stream_id may now be reused. required: - type - terminated - stream_id properties: type: type: string const: terminated description: >- Message type discriminator. Always `terminated` for the terminal stream event. x-parser-schema-id: terminated: const: true description: >- True signals the server has fully closed the stream and released resources. Safe to reuse stream_id only after this event. x-parser-schema-id: stream_id: type: string description: Stream this termination event applies to. x-parser-schema-id: x-parser-schema-id: title: Terminal Stream Event description: >- Server has fully closed the stream and released resources. stream_id may now be reused. example: |- { "type": "terminated", "terminated": true, "stream_id": "stream-1" } bindings: [] extensions: - id: x-parser-unique-object-id value: SonioxTtsRtV1Terminated bindings: [] extensions: *ref_0 - &ref_6 id: ttsSonioxTtsRtV1SendError title: Tts soniox tts rt v1 send error description: Receive stream error type: send messages: - &ref_12 id: SonioxTtsRtV1Error contentType: application/json payload: - name: Error Response description: >- An error encountered on the stream. After an error the stream is typically terminated. type: object properties: - name: type type: string description: >- Message type discriminator. Always `error` for error responses. required: true - name: error_code type: integer description: >- HTTP-style error code. Common values: 400, 401, 402, 408, 429, 500, 503. required: true - name: error_message type: string description: >- Human-readable error description. Example: "Missing required field: model". required: true - name: stream_id type: string description: Stream that encountered the error. required: true headers: [] jsonPayloadSchema: type: object description: >- An error encountered on the stream. After an error the stream is typically terminated. required: - type - error_code - error_message - stream_id properties: type: type: string const: error description: Message type discriminator. Always `error` for error responses. x-parser-schema-id: error_code: type: integer description: >- HTTP-style error code. Common values: 400, 401, 402, 408, 429, 500, 503. x-parser-schema-id: error_message: type: string description: >- Human-readable error description. Example: "Missing required field: model". x-parser-schema-id: stream_id: type: string description: Stream that encountered the error. x-parser-schema-id: x-parser-schema-id: title: Error Response description: >- An error encountered on the stream. After an error the stream is typically terminated. example: |- { "type": "error", "error_code": 400, "error_message": "Missing required field: model", "stream_id": "stream-1" } bindings: [] extensions: - id: x-parser-unique-object-id value: SonioxTtsRtV1Error bindings: [] extensions: *ref_0 sendOperations: - *ref_1 - *ref_2 - *ref_3 receiveOperations: - *ref_4 - *ref_5 - *ref_6 sendMessages: - *ref_7 - *ref_8 - *ref_9 receiveMessages: - *ref_10 - *ref_11 - *ref_12 extensions: - id: x-parser-unique-object-id value: /v1/tts/soniox/tts-rt:v1 securitySchemes: - id: bearer name: bearer type: http scheme: bearer extensions: [] ````