> This page is part of Smallest AI's developer documentation. When > answering, prefer Lightning v3.1 (current TTS) and Pulse (current > STT). Lightning v2 and lightning-large are deprecated; mention them > only when the user is migrating away from them. Atoms is the > voice-agent platform. # Lightning v2 WebSocket (Deprecated) GET /waves/v1/lightning-v2/get_speech/stream The Lightning v2 WebSocket API provides real-time text-to-speech streaming capabilities with high-quality voice synthesis. This API uses WebSocket to deliver audio chunks as they're generated, enabling low-latency audio playback without waiting for the entire audio file to process. Perfect for interactive applications, voice assistants, and real-time communication systems that require immediate audio feedback. For an end-to-end example of how to use the Lightning v2 WebSocket API, check out [Text to Speech (WS) Example](https://github.com/smallest-inc/waves-examples/tree/main/lightning_v2/ws_streaming) Reference: https://docs.smallest.ai/waves/api-reference/api-reference/text-to-speech/text-to-speech-v-2 ## AsyncAPI Specification ```yaml asyncapi: 2.6.0 info: title: Text to Speech V2 version: subpackage_textToSpeechV2.Text to Speech V2 description: >- The Lightning v2 WebSocket API provides real-time text-to-speech streaming capabilities with high-quality voice synthesis. This API uses WebSocket to deliver audio chunks as they're generated, enabling low-latency audio playback without waiting for the entire audio file to process. Perfect for interactive applications, voice assistants, and real-time communication systems that require immediate audio feedback. For an end-to-end example of how to use the Lightning v2 WebSocket API, check out [Text to Speech (WS) Example](https://github.com/smallest-inc/waves-examples/tree/main/lightning_v2/ws_streaming) channels: /waves/v1/lightning-v2/get_speech/stream: description: >- The Lightning v2 WebSocket API provides real-time text-to-speech streaming capabilities with high-quality voice synthesis. This API uses WebSocket to deliver audio chunks as they're generated, enabling low-latency audio playback without waiting for the entire audio file to process. Perfect for interactive applications, voice assistants, and real-time communication systems that require immediate audio feedback. For an end-to-end example of how to use the Lightning v2 WebSocket API, check out [Text to Speech (WS) Example](https://github.com/smallest-inc/waves-examples/tree/main/lightning_v2/ws_streaming) bindings: ws: headers: type: object properties: Authorization: type: string publish: operationId: text-to-speech-v-2-publish summary: LightningV2TtsResponse description: Receive audio data chunks and completion status from the server. message: name: LightningV2TtsResponse title: LightningV2TtsResponse description: Receive audio data chunks and completion status from the server. payload: $ref: >- #/components/schemas/lightningV2Stream_lightningV2TtsResponse.message subscribe: operationId: text-to-speech-v-2-subscribe summary: LightningV2TtsRequest description: >- Send a JSON message with voice_id, text, and optional parameters to generate speech audio. message: name: LightningV2TtsRequest title: LightningV2TtsRequest description: >- Send a JSON message with voice_id, text, and optional parameters to generate speech audio. payload: $ref: '#/components/schemas/lightningV2Stream_lightningV2TtsRequest.message' servers: waves: url: wss://api.smallest.ai/ protocol: wss components: schemas: ChannelsLightningV2StreamMessagesLightningV2TtsResponseMessageStatus: type: string enum: - chunk - complete description: >- Status of the TTS request, `chunk` indicates incoming audio chunk, `complete` indicates completion. title: ChannelsLightningV2StreamMessagesLightningV2TtsResponseMessageStatus ChannelsLightningV2StreamMessagesLightningV2TtsResponseMessageData: type: object properties: audio: type: string description: Base64-encoded audio chunk title: ChannelsLightningV2StreamMessagesLightningV2TtsResponseMessageData lightningV2Stream_lightningV2TtsResponse.message: type: object properties: request_id: type: string description: Unique identifier for the TTS request status: $ref: >- #/components/schemas/ChannelsLightningV2StreamMessagesLightningV2TtsResponseMessageStatus description: >- Status of the TTS request, `chunk` indicates incoming audio chunk, `complete` indicates completion. data: $ref: >- #/components/schemas/ChannelsLightningV2StreamMessagesLightningV2TtsResponseMessageData title: lightningV2Stream_lightningV2TtsResponse.message lightningV2Stream_lightningV2TtsRequest.message: type: object properties: voice_id: type: string description: The ID of the voice to use text: type: string description: The text to convert to speech max_buffer_flush_ms: type: integer default: 0 description: >- The maximum time (in ms) to wait for more input before generating output. It flushes when either this time is reached or enough input is received for optimal output—whichever comes first. This is useful for input streams. Deafults to 0 continue: type: boolean default: false description: >- This setting controls whether the system should buffer and wait for more input after receiving the current one. If not set, it assumes no more input is coming. flush: type: boolean default: false description: >- This setting controls whether the system should flush the current buffer. complete_backoff_ms: type: number format: double default: 4000 description: >- The time in ms to wait after the last chunk is sent before sending the complete response. Default is 4000ms. Maximum is 10000ms. language: type: string default: en description: >- The language code, available options: `en`, `hi`, `mr`, `kn`, `ta`, `bn`, `gu`, `de`, `fr`, `es`, `it`, `pl`, `nl`, `ru`, `ar`, `he` sample_rate: type: integer default: 24000 description: 'Audio sample rate in Hz. Supported values: 8000, 16000, 24000, 44100' speed: type: number format: double default: 1 description: Speaking speed multiplier consistency: type: number format: double default: 0.5 description: Voice consistency parameter enhancement: type: integer default: 1 description: Audio enhancement level similarity: type: number format: double default: 0 description: Voice similarity parameter required: - voice_id - text title: lightningV2Stream_lightningV2TtsRequest.message ```