> ## Documentation Index > Fetch the complete documentation index at: https://dify-6c0370d8-fix-template-upload-size-guidance.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Convert Text to Audio > **Available for**: Chatflow, Workflow, Agent, Chatbot, Legacy Agent, Text Generator apps. Converts text to speech audio. Pass `text` to synthesize arbitrary text, or `message_id` to voice an existing message's answer. ## OpenAPI ````yaml /en/api-reference/openapi_service.json post /text-to-audio openapi: 3.0.1 info: description: >- REST API for Dify applications and knowledge bases. Application endpoints authenticate with an app API key; knowledge endpoints authenticate with a dataset API key. title: Dify Service API version: 1.0.0 servers: - description: >- Base URL of the Dify Service API. For self-hosted deployments, replace it with your own API base URL. url: https://{api_base_url} variables: api_base_url: default: api.dify.ai/v1 description: Host and path of the API base URL, without the `https://` prefix. security: - ApiKeyAuth: [] tags: - description: Operations related to chat messages and interactions. name: Chat Messages - description: File upload and preview operations. name: Files - description: Operations related to end user information. name: End Users - description: User feedback operations. name: Feedback - description: Operations related to managing conversations. name: Conversations - description: Text-to-Speech and Speech-to-Text operations. name: Audio - description: Operations to retrieve application settings and information. name: Applications - description: Operations related to managing annotations for direct replies. name: Annotations - description: Endpoints for resuming paused workflows that require human input. name: Human Input - description: Operations for executing and managing workflows. name: Workflow Runs - description: Operations related to text generation and completion. name: Completion Messages - description: >- Operations for managing knowledge bases, including creation, configuration, and retrieval. name: Knowledge Bases - description: >- Operations for creating, updating, and managing documents within a knowledge base. name: Documents - description: Operations for managing document chunks and child chunks. name: Chunks - description: >- Operations for managing knowledge base metadata fields and document metadata values. name: Metadata - description: Operations for managing knowledge base tags and tag bindings. name: Tags - description: Operations for retrieving available models. name: Models - description: >- Operations for managing and running knowledge pipelines, including datasource plugins and pipeline execution. name: Knowledge Pipeline paths: /text-to-audio: post: tags: - Audio summary: Convert Text to Audio description: >- **Available for**: Chatflow, Workflow, Agent, Chatbot, Legacy Agent, Text Generator apps. Converts text to speech audio. Pass `text` to synthesize arbitrary text, or `message_id` to voice an existing message's answer. operationId: textToAudioChat requestBody: content: application/json: examples: textToAudioExample: summary: Request Example value: streaming: false text: Hello, welcome to our service. user: abc-123 voice: alloy schema: $ref: '#/components/schemas/TextToAudioRequest' required: true responses: '200': content: audio/aac: schema: format: binary type: string audio/flac: schema: format: binary type: string audio/mp4: schema: format: binary type: string audio/mpeg: schema: format: binary type: string audio/ogg: schema: format: binary type: string audio/wav: schema: format: binary type: string audio/webm: schema: format: binary type: string description: >- Returns the generated audio. The `Content-Type` header reflects the provider's audio container, verified from the response bytes when recognizable. The body can be AAC, FLAC, MP4, MP3, Ogg, WAV, or WebM. Output that cannot be recognized is labeled with the provider's declared type, or `audio/mpeg` when none is declared. Streamed provider output is delivered with chunked transfer encoding; the request `streaming` field does not control this. '400': content: application/json: examples: app_unavailable: summary: app_unavailable value: code: app_unavailable message: App unavailable, please check your app configurations. status: 400 completion_request_error: summary: completion_request_error value: code: completion_request_error message: Completion request failed. status: 400 invalid_param: summary: invalid_param value: code: invalid_param message: TTS is not enabled status: 400 model_currently_not_support: summary: model_currently_not_support value: code: model_currently_not_support message: >- Dify Hosted OpenAI trial currently not support the GPT-4 model. status: 400 provider_not_initialize: summary: provider_not_initialize value: code: provider_not_initialize message: >- No valid model provider credentials found. Please go to Settings -> Model Provider to complete your provider credentials. status: 400 provider_quota_exceeded: summary: provider_quota_exceeded value: code: provider_quota_exceeded message: >- Your quota for Dify Hosted OpenAI has been exhausted. Please go to Settings -> Model Provider to complete your own provider credentials. status: 400 description: >- - `app_unavailable` : The app is unavailable or misconfigured. - `invalid_param` : Text-to-speech is not enabled, `text` is missing, or no voice is available. - `provider_not_initialize` : No valid model provider credentials are configured. - `provider_quota_exceeded` : The model provider quota is exhausted. - `model_currently_not_support` : The current model does not support this operation. - `completion_request_error` : The text-to-speech request failed. '500': content: application/json: examples: internal_server_error: summary: internal_server_error value: code: internal_server_error message: >- The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application. status: 500 description: '`internal_server_error` : Internal server error.' components: schemas: TextToAudioRequest: description: >- Request body for text-to-audio conversion. Provide either `message_id` or `text`. properties: message_id: description: >- ID of the message whose answer to voice. Takes priority over `text` when both are provided. Get message IDs from [List Conversation Messages](/en/api-reference/conversations/list-conversation-messages). format: uuid type: string streaming: description: >- Accepted for backward compatibility but has no effect. Whether the audio is streamed is determined by the configured TTS provider's output, not by this field. type: boolean text: description: Text to synthesize into speech. type: string user: description: >- End-user identifier, defined by your app and unique within it. See [End User Identity](/en/api-reference/guides/end-user-identity). type: string voice: description: >- Voice to use for text-to-speech. Available voices depend on the TTS provider configured for this app. Use the `voice` value from [Get App Parameters](/en/api-reference/applications/get-app-parameters) → `text_to_speech.voice` for the default. type: string type: object securitySchemes: ApiKeyAuth: bearerFormat: API_KEY description: >- Every request authenticates with an API key: `Authorization: Bearer {API_KEY}`. App endpoints take an app API key; knowledge endpoints take a knowledge base API key ([Get Started](/en/api-reference/guides/get-started)). Keep keys server-side; never embed them in client code. Requests with a missing or invalid key fail with HTTP `401` (`unauthorized`). scheme: bearer type: http ````